2010 D22 YD25 Coolant drain - My how to..

[Gorb]

Hi,

Just posting this out of general interest as I couldn't find any common thread of how to:

I managed to drain my coolant from block and radiator by doing this. I am not a mechanic but I like to tinker, so take this guidance as a possible easy way... Or not! Usual disclaimers, this worked for me.

Sorry I took no photos as I had hassle with block plug, but got it done.

Prep yourself for the job, if you have already started and are looking for help, this may not help.

Make sure you have the right tools:
14mm socket - 6 point socket is thoroughly recommended, 12 point will strip bolt if tight. I also own sockets that are designed to lock onto stripped heads, made by Irwin, don't know what they are called but they are excellent as my bolt was stripped from previous owner and I needed this..
Penetrating Oil. I used WD40 Specialist penetrating oil.
An extension bar of at least 500mm
Trim removal tool, like a little fork (not essential)
Portable light or torch
Jack and axle stands
Catch container, wide open one
If you are short, a step ladder

Locate the drain bolt, It is kind of under the alternator near the block end of the bottom radiator hose. You WILL NOT see it from looking through engine bay. Do it through wheel arch. Turn wheels full lock to the left.
Remove rubber trim at engine bay, use the trim tool or just be careful. The plastic studs pop out but be careful not to tear rubber.
Helps to jack car up slightly, just to raise body slightly but not necessary.
Use torch and look for bolt. IIRC, there is a Nissan Logo on block. Look to front of engine. It is recessed deeply.
When you find it, spray with penetrating oil. Go for a drive and do some stuff in car. When block is hot, repeat.
Leave for 24 hours.

Prep for a few hours and just to be sure, maybe don't need vehicle for tomorrow.
Take some deep breaths and get into it.
1. Undo plastic radiator bung and let that drain and whilst draining, remove airbox lid and the plastic pipe to manifold. (put a clean rag into manifold hole)
2. REMOVE front left wheel. Don't waste time trying to do this with wheel turned, trust me. Support vehicle with axle stands.
3. Remove rubber trim again.
4. I tried using extension bar and breaker bar to reach through past wheel arch and vehicle body but because of length, I need two extn bars and this gave to much flex and was useless. Because you have removed airbox cover, you can now work through engine bay. Use an extension bar that is long enough to work in the space in engine bay, which I think was my 500mm one. (Sorry if that bit is wrong, but I am sure its right). Again, DO NOT use two extension bars due to flex at joint.
5. Reaching through wheel guard, place socket and extension bar onto nut. If you are using a 6 point socket or a stripped socket nut, it will hold. My suggestion is DO NOT use a 12 point socket.
6. If you so desire, place a blanket across top of radiator and front of vehicle grill (to lie on) and lie across and using a normal ratchet, put onto extension bar in a position that you can pull it back towards (anticlockwise). Use step ladder if you are short..
7. Make sure you are on socket properly, now pull back slowly, making sure that socket is well onto bolt the whole time by using one arm to pull back and other to push extension bar toward engine block. DO NOT yank hard just firm force. If you feel it slip or start to round, STOP!! You are going to need the stripped nut sockets.
8. When you feel it slightly move, lube it up again with penetrating oil. Wait 15 - 20 minutes. Continue with point 6 again and it SHOULD start to move and then you are free. Be warned, fluid will pour all over chassis so make sure you have a wide open container.

A couple of precautions. When replacing block bolt, get right in under wheel arch and make sure you line it up. DO NOT try it blindly by feel reaching into engine bay. I dropped my bolt and lost it for 3 hours. Had to pull off bash plate and dick about, losing most of my day. Found it behind alternator bracket after using a piece of mirror, the most obscure spot.

As I lost so much time, I started to rush and don't know if I drained out all of the fluid. Wondering if heater core doesn't drain properly or if vehicle needs to be "nose down" for it to do so. Remember you are slightly up due to wheel off, but I only got about 6.5 litres to go back in. I MAY have an airlock which I will deal with later today, but I do have some odd symptoms.

Vehicle idling for ages with cap off, did not reach operating temp. Is running cool. Took it for a drive and it reached operating temp on gauge (half way), heater is warm but I noticed after drive that thermo may not be opening as I have no apparent circulation AND bottom radiator hose is COLD and top is warm. I have done all the ways I know how to bleed, then ran out of daylight and yet to attack it again this morning.

I notice on this and other general car forums, that others have had this problem with the response varying from "normal" to "cracked heads"... So odd thus far. No overheat, car runs well, in cab heater working, just no apparent flow when looking into radiator whilst car at op temp and cold bottom hose...........??????.......

Anyway, hope this helps someone... Good luck..

 

[grumpy too]

Think you got it all they don't hold much, bit late for me trying to find that block plug but got it eventually only because I had a spare motor on the floor.
Re filling in the manual it says to fill slowly, it gives a rate but I just did it extra slowly and haven't had to top it up at all but filled it pretty quickly previously and had to top it up 3 times after driving 20-30 kms despite trying nose down and nose up so it looks like the airlocks clear if you just dribble the coolant in very slowly?
You normally can't see the water moving in the radiator but it will rise and fall with revs I even put a clear hose on the first EGR hose and on the turbo feed both had no water haven't tried it again since I filled it properly?

 

[Gorb]

Think you got it all they don't hold much, bit late for me trying to find that block plug but got it eventually only because I had a spare motor on the floor.
Re filling in the manual it says to fill slowly, it gives a rate but I just did it extra slowly and haven't had to top it up at all but filled it pretty quickly previously and had to top it up 3 times after driving 20-30 kms despite trying nose down and nose up so it looks like the airlocks clear if you just dribble the coolant in very slowly?
You normally can't see the water moving in the radiator but it will rise and fall with revs I even put a clear hose on the first EGR hose and on the turbo feed both had no water haven't tried it again since I filled it properly?

Thanks Grumpy Too, from what I can garnish from info available, coolant capacity should be 9.4 litres. Your method to clear airlocks for vehicles without a bleed valve is pretty much spot on and that was my plan but the little person in my head told me stop and reconsider everything due to the cold bottom hose.

When I raised the revs on vehicle, coolant did rise and resettled on lower revs as you mention.

The little person in my head, whom I constantly argue with, got the better of me. I decided to start over. Putting aside my aggro of wasting fresh coolant (which was supplied green from Nissan, replacing orange, even though Blue is now the type apparently used since 2009 :roll eyes: ) and dreading taking out the thermostat - as previous vehicle was a nightmare to get to reseal and that was in an easier to get to spot - I bit the bullet. With our summer coming on, lets not P155 about.

*The short story for those who have experienced a COLD bottom radiator hose, warm to hot top hose - temperature gauge reading normal - heater blowing hot air as it should - car running normal and happy, check your thermostat. LATE EDIT In my case the thermostat was not opening. **See below post, my test protocol was flawed, thermo does work** This situation would seem normal for this vehicle. Leaves the thought on how accurate is the temperature gauge is or where do they place the sensor of gauge or how efficient is this cooling system? My test drive was two 15 - 20 minute drives, one was "cleaning out some carbon from previous owners city driving". Vehicle does not appear to have overheated, but who really knows. Certainly wasn't popping and pinging or smelling weird when I turned it off. Ambient temperature of the day was only about 12 degrees Celsius and I have had the car for about a week and I live rural, all highway driving.

* The long story. Removing the thermostat was a relief. The gasket is a beautiful thick rubber O ring that sits in its own recess. I could use it again (and have for now) as I have reassembled temporarily, without thermostat. I have not torqued up the bolts and no sign of leak but of course, system is running very cool so minimal pressure. I have small girlie hands, so it wasn't too bad a job to do to remove the 3 bolts holding housing, but I do recommend removing the air box lid and plastic tube to manifold. It's pretty straight forward, just working around air con hoses.

Thermostat is physically large compared to what I have seen on other vehicles. As a side note, rang my local generic parts store. Aftermarket one to order in was $60 at time of writing, plus another $6 O ring, need to order it in. Decided to ring Nissan to try and get one immediately, fearing the cost. In stock @ half the price! Yep, half the price!! Included O ring. I decided to also get a new engine block drain plug, only comes in a pack of 5 at a cost that I would have expected to pay for one. Be aware, the parts guy I dealt with was excellent and bolt was hard to find. Nissan parts list call it simply a threaded bolt from what I recall and it was only picked up from looking at diagrams. It's not a plug or bung or block off. Very annoying. Anyway, genuine prices surprised me.

With thermostat out, in my case I can see coolant moving/agitating through radiator top. Hopefully suggests water pump is currently pumping. Higher revs does raise the level up the spout, but not as much as it did prior to removing dodgy thermostat.

Going to pick up parts this morning ( a fun round trip of 130km's) then will hopefully be sorted in the cooling system..

COOLANT: Thought I would raise the issue of coolant as I briefly mentioned colours earlier. I try and keep this brief as I know I waffle on..
Coolants look to me to be a topic to send anyone insane. I don't have an owners manual and am still waiting arrival of my workshop manual, so I don't exactly know what was recommended specs originally.
I am no expert, but I do research the wazzoo out of things before making my own conclusion and spent most of last night reading all the crap on Google. In this case, I am going to bite the bullet and use blue... Whilst I don't have money to throw around, putting in blue, as it has no anything (silicate, borates, amines) so must be good for something, maybe the environment. I suspect prior to 2009, the original coolant had low silica formulation and long term use revealed problems. Advancement in tech etc has proven remove silica, all is well. That is my speculation only.

If you do the research and look at Nissan's latest tech bulletin, they switched to blue around late 2009, with some getting blue, some still green. Maybe the diff between Thai and Spain.. So common colours late last decade were "mainly" Red, Green and now Blue. BLUE is backward compatible with NISSAN green. I say Nissan green, because there maybe, possibly a difference between brands, I'm sure there is, but it's an issue about Silica. Many a comment on Google says Nissan branded Green is definitely silica free (so why did Nissan then change to blue if green is free of silica - Blue has been around for awhile for BMW, Audi etc) Apparently, Asian vehicles should have a NO silica formula... When this was decided or if it has been since beginning of time, I can not establish. This is something I had never heard of before but accepted it as there appears to be so much info about not using silica in Asian cars due to abrasion properties when coolant gets old. (Is a Spain built vehicle an Asian vehicle??)

I have some left over Nulon Green Long Life from another vehicle I recently serviced, enough for the D22. As mentioned, Nissan gave me green. I reckon prior to 2010, before the superseding with blue, this product would have been the norm for Nulon to supply (and maybe Penrite). So I jumped onto Nulon website and looked at their product finder. For 2020, they recommend three possible products. 1. is the new super duper ORANGE coolant, 10 year 1 million Km's compatible with EVERYTHING on Aus and NZ roads. Never seen this before.. 2. Then there is a reddish one, but it is not your normal old school Red OAT formulas for brass and copper stuff, it's a new high tech diesel specific, which I disregarded 3. Then there is Blue, specially formulated for Asian OEM, no silica formula, as per Nissan tech bulletin. Then there is a small note on the blue which says, if current coolant Green, Use LL coolant. Search their site and LL is their green long life, which I have. Read about the qualities of their green, and it is not a NO silica product, but a LOW silica product. All the wisdom of thousands of minds suggest Asian vehicles inc Nissan should have NO SILICA. Some even warn about LOW silica suggesting, How much is LOW?

Jump on Penrite, their number 1 is BLUE and number 2 is a new ORANGE mix with anything, any car super fluid.. It appears more of a multi compatible top up fluid as opposed to full replacement by the looks. No mention of green for Nissan on Penrite anywhere.

Then there is Preston Coolant and they have a red for Asian, Green for Asian and a blue for Asian. Good grief Charlie Brown.

So yeah, good luck with all that...

Hope this minutia is of value to someone, somewhere.. Cheers

EDIT: You've got to love propaganda and the confusion involved to make you buy the dearest product - Nissan Coolant Bottle shows their coolant is made to "Nissan Engineering Standards" and meets specification of JIS K2234 - searched that and found;

On Penrite
on Nulon

So maybe coolant is not the dark art that it is made out to be.... It would seem ANY Type A coolant is acceptable.

 

[Gorb]

For anyone seeking more information about COOLANT and Blue V Green and silicates in Asian Vehicles. Here is a great read that puts just about all of it in one spot. Water Chemistry would seem to have been the driver to lead to better advancement in coolant. Europe vs Asia - phosphates V silicates.
Australia MAY get away with low silicate formulas but it would seem if you want to change it and change it once and forget - go BLUE. Remember, soft water or demineralised water is the best mix or buy premix.
READ THIS

 

[grumpy too]

Thanks Grumpy Too, from what I can garnish from info available, coolant capacity should be 9.4 litres. Your method to clear airlocks for vehicles without a bleed valve is pretty much spot on and that was my plan but the little person in my head told me stop and reconsider everything due to the cold bottom hose.

When I raised the revs on vehicle, coolant did rise and resettled on lower revs as you mention.

The little person in my head, whom I constantly argue with, got the better of me. I decided to start over. Putting aside my aggro of wasting fresh coolant (which was supplied green from Nissan, replacing orange, even though Blue is now the type apparently used since 2009 :roll eyes: ) and dreading taking out the thermostat - as previous vehicle was a nightmare to get to reseal and that was in an easier to get to spot - I bit the bullet. With our summer coming on, lets not P155 about.

*The short story for those who have experienced a COLD bottom radiator hose, warm to hot top hose - temperature gauge reading normal - heater blowing hot air as it should - car running normal and happy, check your thermostat. In my case the thermostat was not opening. Leaves the thought on how accurate is the temperature gauge is or where do they place the sensor of gauge or how efficient is this cooling system? My test drive was two 15 - 20 minute drives, one was "cleaning out some carbon from previous owners city driving". Vehicle does not appear to have overheated, but who really knows. Certainly wasn't popping and pinging or smelling weird when I turned it off. Ambient temperature of the day was only about 12 degrees Celsius and I have had the car for about a week and I live rural, all highway driving.

* The long story. Removing the thermostat was a relief. The gasket is a beautiful thick rubber O ring that sits in its own recess. I could use it again (and have for now) as I have reassembled temporarily, without thermostat. I have not torqued up the bolts and no sign of leak but of course, system is running very cool so minimal pressure. I have small girlie hands, so it wasn't too bad a job to do to remove the 3 bolts holding housing, but I do recommend removing the air box lid and plastic tube to manifold. It's pretty straight forward, just working around air con hoses.

Thermostat is physically large compared to what I have seen on other vehicles. As a side note, rang my local generic parts store. Aftermarket one to order in was $60 at time of writing, plus another $6 O ring, need to order it in. Decided to ring Nissan to try and get one immediately, fearing the cost. In stock @ half the price! Yep, half the price!! Included O ring. I decided to also get a new engine block drain plug, only comes in a pack of 5 at a cost that I would have expected to pay for one. Be aware, the parts guy I dealt with was excellent and bolt was hard to find. Nissan parts list call it simply a threaded bolt from what I recall and it was only picked up from looking at diagrams. It's not a plug or bung or block off. Very annoying. Anyway, genuine prices surprised me.

With thermostat out, in my case I can see coolant moving through radiator top. Hopefully suggests water pump is currently pumping. Higher revs does raise the level up the spout, but not as much as it did prior to removing dodgy thermostat.

Going to pick up parts this morning ( a fun round trip of 130km's) then will hopefully be sorted in the cooling system..

COOLANT: Thought I would raise the issue of coolant as I briefly mentioned colours earlier. I try and keep this brief as I know I waffle on..
Coolants look to me to be a topic to send anyone insane. I don't have an owners manual and am still waiting arrival of my workshop manual, so I don't exactly know what was recommended specs originally.
I am no expert, but I do research the wazzoo out of things before making my own conclusion and spent most of last night reading all the crap on Google. In this case, I am going to bite the bullet and use blue... Whilst I don't have money to throw around, putting in blue, as it has no anything (silicate, borates, amines) so must be good for something, maybe the environment. I suspect prior to 2009, the original coolant had low silica formulation and long term use revealed problems. Advancement in tech etc has proven remove silica, all is well. That is my speculation only.

If you do the research and look at Nissan's latest tech bulletin, they switched to blue around late 2009, with some getting blue, some still green. Maybe the diff between Thai and Spain.. So common colours late last decade were "mainly" Red, Green and now Blue. BLUE is backward compatible with NISSAN green. I say Nissan green, because there maybe, possibly a difference between brands, I'm sure there is, but it's an issue about Silica. Many a comment on Google says Nissan branded Green is definitely silica free (so why did Nissan then change to blue if green is free of silica - Blue has been around for awhile for BMW, Audi etc) Apparently, Asian vehicles should have a NO silica formula... When this was decided or if it has been since beginning of time, I can not establish. This is something I had never heard of before but accepted it as there appears to be so much info about not using silica in Asian cars due to abrasion properties when coolant gets old. (Is a Spain built vehicle an Asian vehicle??)

I have some left over Nulon Green Long Life from another vehicle I recently serviced, enough for the D22. As mentioned, Nissan gave me green. I reckon prior to 2010, before the superseding with blue, this product would have been the norm for Nulon to supply (and maybe Penrite). So I jumped onto Nulon website and looked at their product finder. For 2020, they recommend three possible products. 1. is the new super duper ORANGE coolant, 10 year 1 million Km's compatible with EVERYTHING on Aus and NZ roads. Never seen this before.. 2. Then there is a reddish one, but it is not your normal old school Red OAT formulas for brass and copper stuff, it's a new high tech diesel specific, which I disregarded 3. Then there is Blue, specially formulated for Asian OEM, no silica formula, as per Nissan tech bulletin. Then there is a small note on the blue which says, if current coolant Green, Use LL coolant. Search their site and LL is their green long life, which I have. Read about the qualities of their green, and it is not a NO silica product, but a LOW silica product. All the wisdom of thousands of minds suggest Asian vehicles inc Nissan should have NO SILICA. Some even warn about LOW silica suggesting, How much is LOW?

Jump on Penrite, their number 1 is BLUE and number 2 is a new ORANGE mix with anything, any car super fluid.. It appears more of a multi compatible top up fluid as opposed to full replacement by the looks. No mention of green for Nissan on Penrite anywhere.

Then there is Preston Coolant and they have a red for Asian, Green for Asian and a blue for Asian. Good grief Charlie Brown.

So yeah, good luck with all that...

Hope this minutia is of value to someone, somewhere.. Cheers

EDIT: You've got to love propaganda and the confusion involved to make you buy the dearest product - Nissan Coolant Bottle shows their coolant is made to "Nissan Engineering Standards" and meets specification of JIS K2234 - searched that and found;

On Penrite
on Nulon

So maybe coolant is not the dark art that it is made out to be.... It would seem ANY Type A coolant is acceptable.

Crikey bloke you are way worse (fickle) than me at researching but nowadays tend to take a few shortcuts just used the Nulon LL which is green (engine has done 280k).
Don't know how you checked your thermostat but I have usually just dropped it in hot water but these engines seem to run really cool unless worked hard or at least most of the radiator is cool, I ran this one here for long periods and the radiator was still very cool and even the EGR hose which seems to take the water in preference to the radiator so if your heater is on it will also cool it down.

 

[Gorb]

Crikey bloke you are way worse (fickle) than me at researching but nowadays tend to take a few shortcuts just used the Nulon LL which is green (engine has done 280k).
Don't know how you checked your thermostat but I have usually just dropped it in hot water but these engines seem to run really cool unless worked hard or at least most of the radiator is cool, I ran this one here for long periods and the radiator was still very cool and even the EGR hose which seems to take the water in preference to the radiator so if your heater is on it will also cool it down.

Yeah fair call GT!! I think you are actually spot on and I learned some lessons. I was going to totally edit my previous posts because there was some failures by me, but figure I'll just expand here.
Story continues:
Got the new thermostat today and some Penrite Blue. Figured I would go the blue as it's an 8 year life or 500 thou km's and as it has no phosphate, instructions say you can use tap water. Where I live, I only have rain water and it is very soft. It's filtered to tiny something and I also boiled it down. Anyway.... Went to put in new thermostat and thought, knowing my luck it won't work so I better test it. Drop it into boiled water and nothing.. NO WAY!!
Thinking what the... It must be my testing conditions. Wife was at work so got out her fancy cooking temperature gauge, dropped it in water and it's 78 degrees. Hmmmm... Tried new boil in kettle, pour it into container and again 83 degrees. Clearly water from kettle cools quick and container exchange drops it quicker than I realised....
So it was my test methodology.. Lesson learnt, if you are testing thermostats, do not use a quick boil kettle and expect it to be hot enough. Somewhere deep down in my head, I think I knew this. So pot on stove, thermostat into it and bring to boil and watch it while boiling. The jokes on me, the old one works also.

Anyway, new thermostat in, full triple flush with shyte load of crud removed and new blue coolant. Job done. Gauge shows just under half at highway speeds, which is about a needle width cooler than previous, bottom hose is warmer, but still very cool not cold, so maybe cleaned out is giving me better flow

These things run cool for sure... I appear to have burnt out fan speed number 1 on heater though.. I'm keeping this one so I might invest in a decent temperature gauge and oil pressure gauge for my onw peace of mind..

Cheers

 

[fuzzylogic]

Interesting info here guys, much appreciated, I recently changed my coolant 2008 D40, and was/am perplexed by the coolness of the bottom radiator hose... car running perfectly, coolant temperature "normal", heater working. I've got an engine watchdog system fitted with 2 sensors on the block, both reading as normal. Drove 500kms over the weekend, 110km/h air-con on, and when I stopped, bottom hose felt quite cool... has anyone else noticed this on their D40's? Cheers

 

[Gorb]

Interesting info here guys, much appreciated, I recently changed my coolant 2008 D40, and was/am perplexed by the coolness of the bottom radiator hose... car running perfectly, coolant temperature "normal", heater working. I've got an engine watchdog system fitted with 2 sensors on the block, both reading as normal. Drove 500kms over the weekend, 110km/h air-con on, and when I stopped, bottom hose felt quite cool... has anyone else noticed this on their D40's? Cheers

Hello fuzzylogic

Presumably you have a YD25, and with the engine watch dog, I'd be pretty comfortable in saying that it is normal for this engine and don't give it a second thought unless something else is presenting. Grumpy Too has offered some logic which also suggests it is not a problem for this vehicle. I can't remember if it is this forum or one of the other Navara forums out there which this topic has been vaguely touched on and suggestion it is normal. Don't go looking generically as you will find suggestions from normal to cracked head and you won't know who/what to trust.... Trust your instinct and YOUR vehicle and what it is doing (if anything other than normal).

It's amazing how certain situations can worry the human mind. I've had this car for a week and standard for me when buying unknown vehicle, is flush and change all fluids. In an agreement with the dealer, I obtained some free genuine Nissan Green Coolant (L248) and did a flush and replaced. It was immediately after that, I was ensuring that air had bled from system that I first noticed the cold bottom hose. I only noticed it because a Google voice suggested squeezing/pumping hoses to help bleed air. A cold hose on a hot engine does not appear to be a reasonable thing and arguably a cause for concern, but that doesn't really mean it's not normal for this car. For me, that concern expanded and led me back to everyone's trusted friend Mr Google (aka Dr Google when your sick) and the resulting overwhelming information available these days, led to inconclusive outcome. I know how my mind works and how doubt can enter, sometimes it runs away, sometimes I can get a grip of it. It got the better of me in this case. What I should have done was have (some) faith in the temp gauge, my own instinct with the smell of vehicle, the running and sounds of it and got on with my life and monitored it for a few days/weeks. But instead I ruminated on it which led me to investigate further and strip it down again, resulting in lost fluid, hassle of disposing 2 lots of coolant, cash etc etc.

When I tested my old thermostat and it appeared to not work, I had this strange sense of relief that there WAS a problem and I had done the right thing and discovered it and knew I could fix it. Then the mind argued, "What if it overheated or something else"... Head gasket, cracked block/head, heat stress blah blah blah... Suddenly I thought I could hear the timing chain, is my clutch working OK?? Pulled my head in and got back on track, got thermostat, outlayed more cash and added further hassle with stressing over coolant "as above" posts discuss, to find out, there was no real issue and it would actually appear to be normal. A lot of wastage and money I could have done without..

In the end, I can now relax with a super efficient cooling system, new thermostat, new engine drain bolt and the latest high tech coolant, but in reality, I could have used left over Nulon Green "LL" coolant still sitting on my shelf at no cost, old thermostat which seems perfectly fine at no cost and the old drain plug, whilst stripped, I had the tools to also re-use, let alone it was around 130km round trip to get parts as well as time and skinned knuckles..

So don't go down my path chasing potentially nothing, if all you have is a cool bottom rad hose, unless of course you enjoy it. Trust in the engine watch dog, I had one in my Patrol and it was excellent, you have the Nissan gauge as back up which should work good enough and your car is running fine....

That's my thought on this matter.. Good luck..

 

[Gorb]

Hi,

Just posting this out of general interest as I couldn't find any common thread of how to:

I managed to drain my coolant from block and radiator by doing this. I am not a mechanic but I like to tinker, so take this guidance as a possible easy way... Or not! Usual disclaimers, this worked for me.

Sorry I took no photos as I had hassle with block plug, but got it done.

Prep yourself for the job, if you have already started and are looking for help, this may not help.

Make sure you have the right tools:
14mm socket - 6 point socket is thoroughly recommended, 12 point will strip bolt if tight. I also own sockets that are designed to lock onto stripped heads, made by Irwin, don't know what they are called but they are excellent as my bolt was stripped from previous owner and I needed this..
Penetrating Oil. I used WD40 Specialist penetrating oil.
An extension bar of at least 500mm
Trim removal tool, like a little fork (not essential)
Portable light or torch
Jack and axle stands
Catch container, wide open one
If you are short, a step ladder

Locate the drain bolt, It is kind of under the alternator near the block end of the bottom radiator hose. You WILL NOT see it from looking through engine bay. Do it through wheel arch. Turn wheels full lock to the left.
Remove rubber trim at engine bay, use the trim tool or just be careful. The plastic studs pop out but be careful not to tear rubber.
Helps to jack car up slightly, just to raise body slightly but not necessary.
Use torch and look for bolt. IIRC, there is a Nissan Logo on block. Look to front of engine. It is recessed deeply.
When you find it, spray with penetrating oil. Go for a drive and do some stuff in car. When block is hot, repeat.
Leave for 24 hours.

Prep for a few hours and just to be sure, maybe don't need vehicle for tomorrow.
Take some deep breaths and get into it.
1. Undo plastic radiator bung and let that drain and whilst draining, remove airbox lid and the plastic pipe to manifold. (put a clean rag into manifold hole)
2. REMOVE front left wheel. Don't waste time trying to do this with wheel turned, trust me. Support vehicle with axle stands.
3. Remove rubber trim again.
4. I tried using extension bar and breaker bar to reach through past wheel arch and vehicle body but because of length, I need two extn bars and this gave to much flex and was useless. Because you have removed airbox cover, you can now work through engine bay. Use an extension bar that is long enough to work in the space in engine bay, which I think was my 500mm one. (Sorry if that bit is wrong, but I am sure its right). Again, DO NOT use two extension bars due to flex at joint.
5. Reaching through wheel guard, place socket and extension bar onto nut. If you are using a 6 point socket or a stripped socket nut, it will hold. My suggestion is DO NOT use a 12 point socket.
6. If you so desire, place a blanket across top of radiator and front of vehicle grill (to lie on) and lie across and using a normal ratchet, put onto extension bar in a position that you can pull it back towards (anticlockwise). Use step ladder if you are short..
7. Make sure you are on socket properly, now pull back slowly, making sure that socket is well onto bolt the whole time by using one arm to pull back and other to push extension bar toward engine block. DO NOT yank hard just firm force. If you feel it slip or start to round, STOP!! You are going to need the stripped nut sockets.
8. When you feel it slightly move, lube it up again with penetrating oil. Wait 15 - 20 minutes. Continue with point 6 again and it SHOULD start to move and then you are free. Be warned, fluid will pour all over chassis so make sure you have a wide open container.

A couple of precautions. When replacing block bolt, get right in under wheel arch and make sure you line it up. DO NOT try it blindly by feel reaching into engine bay. I dropped my bolt and lost it for 3 hours. Had to pull off bash plate and dick about, losing most of my day. Found it behind alternator bracket after using a piece of mirror, the most obscure spot.

As I lost so much time, I started to rush and don't know if I drained out all of the fluid. Wondering if heater core doesn't drain properly or if vehicle needs to be "nose down" for it to do so. Remember you are slightly up due to wheel off, but I only got about 6.5 litres to go back in. I MAY have an airlock which I will deal with later today, but I do have some odd symptoms.

Vehicle idling for ages with cap off, did not reach operating temp. Is running cool. Took it for a drive and it reached operating temp on gauge (half way), heater is warm but I noticed after drive that thermo may not be opening as I have no apparent circulation AND bottom radiator hose is COLD and top is warm. I have done all the ways I know how to bleed, then ran out of daylight and yet to attack it again this morning.

I notice on this and other general car forums, that others have had this problem with the response varying from "normal" to "cracked heads"... So odd thus far. No overheat, car runs well, in cab heater working, just no apparent flow when looking into radiator whilst car at op temp and cold bottom hose...........??????.......

Anyway, hope this helps someone... Good luck..

I can't edit initial post and wanted to add, having accessed the engine drain plug several times now, a couple of extra points to refine initial instructions.
1: Grab an old broom handle/stick/rod to hold your bonnet up from the right hand side so you can keep the factory bonnet prop thingy out of the way. This is really helpful.
2: Trying to locate engine drain bolt is still reasonably hard even when you have done it before. It is almost directly under thermostat housing, in a really deep recess into block. I previously mentioned NISSAN logo on block, it's actually above, in line roughly with the NI of Nissan. You will see it through the wheel arch using a good light. It's just a bolt on it's own, in a deep recess. From the wheel arch, the recess doesn't look that deep, by feel it is.
3: It is much easier to get at if you also remove the thermostat housing, maybe that is a design thing to force you to do it.
4: I drained, Chem flushed, fresh flushed, refilled coolant, drained, chem flushed again, backward flush, fresh water flush and too be sure, fresh water flushed again, and at best with radiator plug and engine block plug removed, could only get at most 6.5 litres out. Heater was open in case you were wondering.
What I wished I had done, at final flush with engine drains open, just turned over the motor for 30 seconds and see if water pump could have forced out a bit more. More curious than anything. That's about all I can really offer on how to...
Don't drop your block plug trying to put it back in, there are not many places for it to get lost, but it will find what is there. I dropped mine twice, not once did it fall through to ground even though visually and logic would suggest it's the most likely option.
The block plug seals really well, you do not need the biggest breaker bar to lock it up. I used some copper grease (any grease will do) as an anti seize on the thread and tighten by hand with an extension bar, then no more than about an 1/8 of a turn with handle. Sealed perfectly.

 

[grumpy too]

Re the comments about head gaskets or cracked head, the water in my overflow was bubbling but there didn't seem to be bubbles in the radiator which started my investigations and findings with the water and airlock issues.
I would suggest if you have a cracked head that will show up as water in oil or bubbles in the radiator but not necessarily in the D22 as the bubbles somehow like the water flow noticed in other cars just doesn't seem to happen visually anyway but if there is air in the water it will exit into the overflow.
In my case besides the water/air problems I had an oil leak at the back of the motor so removed the head and found the head gasket had been damaged presumably at installation and suspect the air/water leak was from the same cause and I suspect the head gasket was reused??
Head tested and reconditioned and filling slowly radiator was filled once only with no bubbles or oil leaks so hopefully all now ok but if not will just buy another wreck or a motor and replace.

 

[Gorb]

but if not will just buy another wreck or a motor and replace.

Me, I'll just drive mine over a cliff....
Good luck with yours, I'm sure having the head recon'd should solve any serious issue.

Cheers

 

[grumpy too]

Yeah if I hadn't put so much into this one I am doing as a project, a write-off would be ok but spent a lot of time on this one up to date, not a lot of money and most of the time has been good during the lockdown but have done this one up to keep.