Engine overheating??

[Leeboy]

Hey peoples,
I’ve recently bought a 2015 np300 st-x from an online auction and after buying it realised it has an obvious overheating issue.
Top hose was red hot and bottom hose cool so I figured no flow so replaced the thermostat ten realised the two electric egr cooler water pumps weren’t working so replaced them both which now work then replaced the radiator which was partially blocked by possibly chemy weld? But still the same. It seems the cooling system is pressurising which to me means cracked head or head gasket so this is the next plan or perhaps replace the engine with a second hand unit. Either way big bucks!
anyone else experienced these issues?
I will keep you all posted with what happens next as it may at least help someone else out there if the same happens to you.
Car has 147000kms and is very tidy looking/ well kept.
My only other thought was perhaps egr cooler cracked but it definitely holds pressure in the cooling system for days after shutting down.
Anyway any thoughts greatly appreciated.
Cheers, Lee.

 

[Tappet]

Sounds like it's been cooked, the fact it runs is a good start so the bottom end, pistons and rings has survived. If the vehicle is in good nick and you picked up cheap at auction. Which hopefully you did, I would be going down the repair route. You don't know what your going to end up with, with a second hand donk.

The fact that it maintains pressure in the coolant circuit does not mean combustion pressure is making it way into the coolant circuit via a cracked head or or gasket. Combustion pressure is far greater of course than coolant pressure when running.

Having found possible evidence of Chemiweld in the radiator is not encouraging. If you have the skills to DYI you will save a packet. Even then undertaking such repairs outside of a fully equipped workshop environment can be a little risky.

 

[Old.Tony]

I'd suggest that if the cooling system is holding pressure there's probably no gap in the head gasket/head - if there was one, it's probably sealed.

Do you know that the water pump is working and that there's been no damage to the blades of the pump, or the pump itself hasn't been blocked by anything (corrosion, chem-weld etc) ?

A few people I've spoken to have suggested that Chem-Weld isn't the worst thing you can do to your engine, a couple have insisted that by "repairing" their engine with this product they fixed the problem permanently. Let's say I'm not convinced about the longevity of a silicate (basically glass once it's been heated) added to a crack in a metal cylinder head!

 

[[email protected]]

i have had cracked heads on engines,they always caused overlow pushing water out of radiator... if you remove head make sure you bring up each piston and check for any movement forward and side ways . if there is its going to suck oil ,(thats what my farm ute is now doing ,wouldnt now pass roadworthy as it blows smoke on start up, i fitted a brand new head should have fixed that sloppy piston) you can get pistons resized , they pack them with some clay product which expands them( one engine i have has got water damage in one cylinder (flooding)which then badly scoured the cylinder and siezed a couple of rings , this one didnt show any air bubbles comming up through radiator(signs of compression leak into water) it would overheat then push water out

 

[Been a while]

There are test you can do to see if it is a cracked head, I think there's one that tests for combustion gasses in the radiator for very very minor cracks.. if it is, do it yourself, new head won't set you back much, if your cams and valves stack up ok and are with in specs buy a naked one and fit your valve train and cams..
I'm having issues with mine atm, coming back from QLD with a HUGE load and she got very very hot, turns out I'd cracked the over flow pipe slightly and it wouldn't suck the coolant back from the over flow tank! " well, that's what I'm thinking" Only worked that out when it finally let go completely! Derrr! Fixed it on the track with that plastic weld glue and it got me home...
They would have to be the worst design for a radiator I've seen, I can't be live I didn't break it off years ago with the amount of work I've done on her.. ordered a 3 core alloy job, hopefully that helps with colling..

As Tony wrote, and ill be looking into also if the new radiator doesnt help, is the water pump prop fins! I can't see it being the issue with mine as she has always had clean coolant but...... but you never know eh I'm hoping I can get a cam in there to take a look...

With yours, have a look at pictures of the head gasket, if it's like the zd30 and has these very small water gallery holes it may have chem welded those shut??? Have you tried running her with the thermostat drilled out or removed? Whilst it's out, air and water hose and reverse flush that baby ...

 

[Old.Tony]

Well, guys, it had to happen ...

We got to Bathurst and we're now without the Nav, which is in a workshop awaiting parts.

We stopped at Berry Park just on the east side of the bridge into Bathurst, everything was working fine at this point, engine purred like it's always done, gave it a couple of minutes to cool the turbo and shut her down. Caravan gas on, fridge over to gas, cook some dinner and go to sleep ...

Next morning, get up, coffee, pack things away, get in the car - it's 5 degrees celcius and foggy and even with 93C coolant we've got ZERO heat coming from the air conditioning ... maybe the heater matrix is blocked? Ok, I'll check when we get to the circuit.

So I park the van, disconnect and move the car ... and find a large pool of coolant on the ground. Oh shit. Ring around to a couple of mechanics because I can't see where it's coming from (looks like it might be from the turbocharger's coolant lines) and found one who could see my car today. As in right now. Great, see you soon ...

A few hours later I get a call. "Cracked head mate, right next to a stud".

I've no idea how it happened, I don't let her overheat, I don't rev the guts out of her, I try to keep engine load below 70%. Probably 361,000km on her now.

On the plus side, everything else is working smoothly, we look like we're losing coolant from a crack between the coolant jacket and the outer part of the head, so there's no indication that any coolant may have contaminated the sump or the sump has contaminated the coolant.

We've already ordered a new head (complete with camshafts and valves) which should arrive next week. Mechanic says it'll take him a couple of days. We've organised storage for the caravan, and train trips home on Tuesday. I'll catch the train back here to pick up the car and caravan when the repair's done.

But there you go, even a well-looked-after vehicle can cop head damage too. The mechanic said he's seen a Navara with a crack in the same spot - I might ask him to drop the old head in the tub so I can photograph it and put the pics up here.

As for symptoms - there was only the "no heat from the heater?!?!" and a slow coolant drip.

 

[fuzzylogic]

Well, guys, it had to happen ...

We got to Bathurst and we're now without the Nav, which is in a workshop awaiting parts.

We stopped at Berry Park just on the east side of the bridge into Bathurst, everything was working fine at this point, engine purred like it's always done, gave it a couple of minutes to cool the turbo and shut her down. Caravan gas on, fridge over to gas, cook some dinner and go to sleep ...

Next morning, get up, coffee, pack things away, get in the car - it's 5 degrees celcius and foggy and even with 93C coolant we've got ZERO heat coming from the air conditioning ... maybe the heater matrix is blocked? Ok, I'll check when we get to the circuit.

So I park the van, disconnect and move the car ... and find a large pool of coolant on the ground. Oh shit. Ring around to a couple of mechanics because I can't see where it's coming from (looks like it might be from the turbocharger's coolant lines) and found one who could see my car today. As in right now. Great, see you soon ...

A few hours later I get a call. "Cracked head mate, right next to a stud".

I've no idea how it happened, I don't let her overheat, I don't rev the guts out of her, I try to keep engine load below 70%. Probably 361,000km on her now.

On the plus side, everything else is working smoothly, we look like we're losing coolant from a crack between the coolant jacket and the outer part of the head, so there's no indication that any coolant may have contaminated the sump or the sump has contaminated the coolant.

We've already ordered a new head (complete with camshafts and valves) which should arrive next week. Mechanic says it'll take him a couple of days. We've organised storage for the caravan, and train trips home on Tuesday. I'll catch the train back here to pick up the car and caravan when the repair's done.

But there you go, even a well-looked-after vehicle can cop head damage too. The mechanic said he's seen a Navara with a crack in the same spot - I might ask him to drop the old head in the tub so I can photograph it and put the pics up here.

As for symptoms - there was only the "no heat from the heater?!?!" and a slow coolant drip.

Interesting story Tony, just goes to show how vehicles can fail in random ways, I'll be checking the picture if you post it. I hope the mechanic looks after you. Enjoy your weekend anyway...

 

[Been a while]

Well, guys, it had to happen ...

We got to Bathurst and we're now without the Nav, which is in a workshop awaiting parts.

We stopped at Berry Park just on the east side of the bridge into Bathurst, everything was working fine at this point, engine purred like it's always done, gave it a couple of minutes to cool the turbo and shut her down. Caravan gas on, fridge over to gas, cook some dinner and go to sleep ...

Next morning, get up, coffee, pack things away, get in the car - it's 5 degrees celcius and foggy and even with 93C coolant we've got ZERO heat coming from the air conditioning ... maybe the heater matrix is blocked? Ok, I'll check when we get to the circuit.

So I park the van, disconnect and move the car ... and find a large pool of coolant on the ground. Oh shit. Ring around to a couple of mechanics because I can't see where it's coming from (looks like it might be from the turbocharger's coolant lines) and found one who could see my car today. As in right now. Great, see you soon ...

A few hours later I get a call. "Cracked head mate, right next to a stud".

I've no idea how it happened, I don't let her overheat, I don't rev the guts out of her, I try to keep engine load below 70%. Probably 361,000km on her now.

On the plus side, everything else is working smoothly, we look like we're losing coolant from a crack between the coolant jacket and the outer part of the head, so there's no indication that any coolant may have contaminated the sump or the sump has contaminated the coolant.

We've already ordered a new head (complete with camshafts and valves) which should arrive next week. Mechanic says it'll take him a couple of days. We've organised storage for the caravan, and train trips home on Tuesday. I'll catch the train back here to pick up the car and caravan when the repair's done.

But there you go, even a well-looked-after vehicle can cop head damage too. The mechanic said he's seen a Navara with a crack in the same spot - I might ask him to drop the old head in the tub so I can photograph it and put the pics up here.

As for symptoms - there was only the "no heat from the heater?!?!" and a slow coolant drip.

Ohhh Noooooo... not good bloke, lucky catch in a way huh


man, i cant wait to see those pictures..

 

[ericcs]

Well, guys, it had to happen ...

We got to Bathurst and we're now without the Nav, which is in a workshop awaiting parts.

We stopped at Berry Park just on the east side of the bridge into Bathurst, everything was working fine at this point, engine purred like it's always done, gave it a couple of minutes to cool the turbo and shut her down. Caravan gas on, fridge over to gas, cook some dinner and go to sleep ...

Next morning, get up, coffee, pack things away, get in the car - it's 5 degrees celcius and foggy and even with 93C coolant we've got ZERO heat coming from the air conditioning ... maybe the heater matrix is blocked? Ok, I'll check when we get to the circuit.

So I park the van, disconnect and move the car ... and find a large pool of coolant on the ground. Oh shit. Ring around to a couple of mechanics because I can't see where it's coming from (looks like it might be from the turbocharger's coolant lines) and found one who could see my car today. As in right now. Great, see you soon ...

A few hours later I get a call. "Cracked head mate, right next to a stud".

I've no idea how it happened, I don't let her overheat, I don't rev the guts out of her, I try to keep engine load below 70%. Probably 361,000km on her now.

On the plus side, everything else is working smoothly, we look like we're losing coolant from a crack between the coolant jacket and the outer part of the head, so there's no indication that any coolant may have contaminated the sump or the sump has contaminated the coolant.

We've already ordered a new head (complete with camshafts and valves) which should arrive next week. Mechanic says it'll take him a couple of days. We've organised storage for the caravan, and train trips home on Tuesday. I'll catch the train back here to pick up the car and caravan when the repair's done.

But there you go, even a well-looked-after vehicle can cop head damage too. The mechanic said he's seen a Navara with a crack in the same spot - I might ask him to drop the old head in the tub so I can photograph it and put the pics up here.

As for symptoms - there was only the "no heat from the heater?!?!" and a slow coolant drip.

did you get your car going again Tony?

 

[Old.Tony]

It's still at the mechanics' at Bathurst. Will be ringing them today to make sure it's done, but I expect it to be ready. I can't get up to Bathurst until Monday - prior obligations that I can't shift.

However, the last word I had from the mechanic was very good - he asked me if I'd recently had a timing chain kit installed, because the gear looked near new. I told him he was the first to have seen the timing chain since the car left the factory and he was shocked!

 

[ericcs]

It's still at the mechanics' at Bathurst. Will be ringing them today to make sure it's done, but I expect it to be ready. I can't get up to Bathurst until Monday - prior obligations that I can't shift.

However, the last word I had from the mechanic was very good - he asked me if I'd recently had a timing chain kit installed, because the gear looked near new. I told him he was the first to have seen the timing chain since the car left the factory and he was shocked!

that's good to know about the chain. mine's at 290k, and still perfectly quiet, finger's crossed!

 

[Old.Tony]

So I got the call this afternoon ...

My Navara has done a couple of laps of Mt Panorama and there are no leaks, no odd noises, it's ready to go.

My train awaits! No idea of the cost yet, will find that out on Monday!