EGR question

[kezza170]

has anybody that has done an egr block off actually not worried with putting half the egr crap back on the car as i cant see the point when it will be blocked off and useless anyhoo. But didnt want to just go do it incase there is a purpose of putting the parts back on there.
Cheers in advance

 

[tweak'e]

afaik removing emission gear is illegal in AU. best to just leave it there.

 

[Lewdy]

has anybody that has done an egr block off actually not worried with putting half the egr crap back on the car as i cant see the point when it will be blocked off and useless anyhoo. But didnt want to just go do it incase there is a purpose of putting the parts back on there.
Cheers in advance

Removing it is illegal, I’d imagine the only person who’d ever notice is your mechanic and he’d hopefully not report you, but better to be safe.

If you failed your MOT on emissions it would be better if it was there as the first thing they would probably want to do is put the exhaust system back to the way it’s meant to be.

 

[grumpy too]

You can get a cable to disable the egr instead of blocking or removing etc and then it can just be removed if needed and no one is the wiser but pretty exxy EGR BLANK MODULE to suit: Nissan Navara YD25 D40 D22 | eBay

 

[tweak'e]

You can get a cable to disable the egr instead of blocking or removing etc and then it can just be removed if needed and no one is the wiser but pretty exxy EGR BLANK MODULE to suit: Nissan Navara YD25 D40 D22 | eBay

wow, $119 for a few plugs and a resistor.
all it does is trick the air temp sensor into reading as very very cold. ecu responds by shutting off egr. however you have no idea what other cold weather related things the ecu does.

 

[sparkybg]

If this is the way it works, don't use it! Remap is the best thing that can be used.

 

[grumpy too]

wow, $119 for a few plugs and a resistor.
all it does is trick the air temp sensor into reading as very very cold. ecu responds by shutting off egr. however you have no idea what other cold weather related things the ecu does.

If it only has a resistor definitely more of a waste of money except it can be removed easily if needed but if you read down the description it does seem to do a bit more than that to work with the ECU???
Just read the full details on that cable again, it says if you use it you don't need or get any benefit with a catch can but I must be missing something, as I see it the catch can catches oily gas from the engine usually blow by which if not collected it goes straight into the inlet prior the intercooler which oils it and the inlet manifold up if excessive, so how does the egr bypass stop this oily gas?

 

[blackpete]

I have been using this cable mod. for over a year now no codes and no other problems.

 

[grumpy too]

Do you still get oil from the PCV hose though the turbo and intercooler? I can't see how any mod to the EGR setup will stop that as they say and that oil through the turbo can apparently cause problems if working hard and not using a timer to cool it.
My driver 2011 with EGR block and no catch can is dribbling oil at the intercooler inlet hose, my project 2009 has EGR block but very little oil in intercooler and pipes even though it has done 280k it has a cheap catch can but done no work with it yet and am changing catch can to a provent type just keep it clean.

 

[tweak'e]

Just read the full details on that cable again, it says if you use it you don't need or get any benefit with a catch can

thats just marketing BS. they are selling a $20 item for $100+, you kinda expect the BS.

 

[sparkybg]

I have been using this cable mod. for over a year now no codes and no other problems.

...so far.

The ECU absolutely MUST know the engine temperature.

 

[sparkybg]

Do you still get oil from the PCV hose though the turbo and intercooler? I can't see how any mod to the EGR setup will stop that as they say and that oil through the turbo can apparently cause problems if working hard and not using a timer to cool it.
My driver 2011 with EGR block and no catch can is dribbling oil at the intercooler inlet hose, my project 2009 has EGR block but very little oil in intercooler and pipes even though it has done 280k it has a cheap catch can but done no work with it yet and am changing catch can to a provent type just keep it clean.

Timer to cool what? The PCV oil is normal, unless the oil consumption is more than 300ml/1000km. And even then it is not that much of a problem if turbo is OK. Oil consumption of around 100ml/1000km is considered normal in most turbo engines, ZD30 included.

 

[Yogi_97]

...so far.

The ECU absolutely MUST know the engine temperature.

The cable only cheats the air intake temp not the engine temperature. The ambient temp on the dash is still accurate.
With this the EGR stays fully closed unlike the block off that needs an 8mm hole where Oil and crap still goes back into the intake and will eventually settle in the intercooler at the lowest point. (Be a good place to put a drain bung?)
Ive had a cable on for quite a while and its running sweet, I also changed the split intercooler for a full aftermarket system at same time.

 

[sparkybg]

The ambient temp on the dash is still accurate.

Of course it is accurate. Ambient temp sensor has nothing to do with the engine. It only shows outside temperature (which is different from air intake temperature) on the dash, but I cannot see such sensor on Navara D22's service manual.
Moreover, there's separate sensors for coolant temperature on the dash, and coolant temperature for the ECU. The sensor for the dash is placed on the RH side on the engine's head, and the ECU sensor is located on the LH side, on the water pipe coming from the water pump.

With this the EGR stays fully closed...

Wrong. The EGR is controlled by the coolant temperature and engine revs (I am looking at the ECU EGR map right now). Intake air temperature has nothing to do with the EGR. It is used together with MAP sensor and engine revs in order to calculate how much air gets into the engine, because there's no MAF sensor on navara's ZD30.

...and, IMHO, with EGR closed, the catch can is pointless. On the vehicles with intercooler it is placed in a way that prevents oil from settling in the intercooler - the intercooler intake port is higher than output port and all the oil goes to the engine's intake manifold. When using good oil, the intercooler never gets clogged - the oil constantly washes everything away from it. The oil in the intake manifold is a bad thing only when it is mixed with the carbon particles from the EGR. So no EGR - no problem. I mean when factory intercooler like on Patrol's ZD30 is used.

 

[grumpy too]

Timer to cool what? The PCV oil is normal, unless the oil consumption is more than 300ml/1000km. And even then it is not that much of a problem if turbo is OK. Oil consumption of around 100ml/1000km is considered normal in most turbo engines, ZD30 included.

Ok maybe we are talking different motors but it is my understanding that if the turbo has been working hard (towing) you should use a turbo timer to cool it down prior to switching off so the oil doesn't bake? in the cooling lines or maybe even that coming from the PCV to it.

With this the EGR stays fully closed unlike the block off that needs an 8mm hole where Oil and crap still goes back into the intake and will eventually settle in the intercooler at the lowest point.

Never seen a block plate with a hole in it of the four motors here blocked none have holes? but one I haven't stripped yet so maybe it has and maybe the 25YD is different also if intercooler input is higher it is only fractionally, re oil going from the PCV hose to input side of turbo, that oil is hot and can collect especially if turbo is hotter?
Your explanation of why the EGR valve can carbonise the oil in inlet manifold makes sense too and explains the blurb from the mob marketing the cable block thanks, but would prefer the shit in the oil from the PCV to be left in the catch can rather than be recirculated back into engine especially top of engine.
Grandson no2 put a catch can on his ZD30 and the engine oil instead of being black on changes was clean due to being filtered through can?

 

[bods]

D22 yd25 won't throw engine codes with the egr blocked. It hasn't got a flow sensor in it, my 2010 was blocked from around 7000km and I sold it with about 125k km on it and never had an engine light or any codes at all, let alone egr.

As for the turbo timer, all they do is allow the engine to idle without having the ignition turned on. Without an oil temp gauge or egt gauge, you have no idea how long you need to idle it for to cool the turbo down, plus the modern water cooled turbos aren't as critical and the siphon effect of the coolant removes heat.

A catch can just stops the oil being fed back into the intake manifold, as mentioned. Blocking the egr just stops the pcv oil from being baked onto the intake manifold, as well as not feeding exhaust gas back into the motor, obviously... As well as keeping the oily residue out of the intake manifold and intercooler, it can also stop oil vapour moving back out the inlet tubing to the air filter and dirtying the maf sensor on engines fitted with them.

 

[tweak'e]

Of course it is accurate. Ambient temp sensor has nothing to do with the engine. It only shows outside temperature (which is different from air intake temperature) on the dash, but I cannot see such sensor on Navara D22's service manual.
Moreover, there's separate sensors for coolant temperature on the dash, and coolant temperature for the ECU. The sensor for the dash is placed on the RH side on the engine's head, and the ECU sensor is located on the LH side, on the water pipe coming from the water pump.


Wrong. The EGR is controlled by the coolant temperature and engine revs (I am looking at the ECU EGR map right now). Intake air temperature has nothing to do with the EGR. It is used together with MAP sensor and engine revs in order to calculate how much air gets into the engine, because there's no MAF sensor on navara's ZD30.

...and, IMHO, with EGR closed, the catch can is pointless. On the vehicles with intercooler it is placed in a way that prevents oil from settling in the intercooler - the intercooler intake port is higher than output port and all the oil goes to the engine's intake manifold. When using good oil, the intercooler never gets clogged - the oil constantly washes everything away from it. The oil in the intake manifold is a bad thing only when it is mixed with the carbon particles from the EGR. So no EGR - no problem. I mean when factory intercooler like on Patrol's ZD30 is used.

common rail D22 probably has the air temp sensor, typically its in the MAF housing.
this discussion is more on the D40, tho i've seen the air temp hack for D23's.
zd30 has a more simpler setup due to the lower amount of egr it uses.

i suspect the way it works is manufactures knows that in very cold conditions the engine combustion temp doesn't get high enough to produce Nox, so egr is not required.
the catch of tricking the temp sensor is if its used for other features.

 

[sparkybg]

Blocking the egr just stops the pcv oil from being baked onto the intake manifold,

Intake manifold doesn't cook/bake anything. In fact it is one of the coolest parts of the engine when running, that's why the PCV oil condenses there. The trouble comes from mixing it with the particles form the EGR. There are several NISSAN engines that come with and without EGR, and you will never see blocked intake on engine without EGR. The baking/cooking comes from the EGR gasses temperature. I am driving my ZD30 with blocked EGR (with remap and 2 blanking plates without any holes) for more than 30000km now. The inside of the intercooler and intake manifold are as bright as they come from factory. There is some oil film and small quantities here and there, but absolutely no residues anywhere. And the oil stays transparent for at least 5000km - it just gets a little darker. I don't see what catch can can do if the EGR is shut off.

Tricking the ECU that either the intake air or coolant temperature is lower puts the engine in non-standart condition. Both the fuel and start of injection aren't as they should be. This is why it is a bad thing, especially on a modern engine without the bigger safety margins of the old ones. Remap of the ECU is the only proper way of shutting down the EGR. Then blanking plates can be used, just in case the EGR valve is not as tight as it should be.

Sure, on some engines there is no problem, but on some other engines (namely YD25 and ZD30, no matter CRD or not) it is definitely a problem, as these are prone to high EGTs even without blocking the EGR.

...and, there's nothing modern in water cooled turbos. Just the opposite - more modern turbos tend to be oil cooled. For example, TD27, ZD30 and several others had water cooled turbos, which were replaced with oil cooled at later time. Usually the oil gets to the turbo directly after the oil-water heat exchanger, so it is with similar temperature. Adding one more cooling agent just adds complexity to the turbo charger if the oil itself is capable enough to cool it down.

As for the timer - I just drive a bit slower some minutes before stopping, and eventually letting the engine work at idle for some 30-60 seconds. Never had any turbocharger issues. And I am replacing my oil twice a year (which in my case is around 7500-10000km, using only high quality fully synthetic oils which deteriorate considerably slower. Namely AMSOIL for example. Never had any issues with oil either.

 

[richNAV]

I thought I would resurrect this post as I’m about to do Catch Can and EGR blanking on my ZD30...and the responses above suggest an ECU remap is the way to go in conjunction with 2x blanking plates. But then a Catch Can is not really required. What’s other thoughts on this?

 

[Old.Tony]

The changes you're suggesting are for different things.

Catch can is designed to intercept oil vapour coming out of the crankcase breather (PCV). Intercepting this oil prevents it from entering the intercooler and reducing its effectiveness, and prevents it from entering the intake manifold where it combines with soot from EGR to form a black gluggy clump mess. Adding a catch can does not violate emission control measures,

EGR on the other hand is an emission control device. It dampens combustion to prevent oxides of nitrogen (greenhouse gases) from being formed during combustion. EGR is only active in mid-range throttle, so not at idle and not at full throttle. By dampening the combustion, the fuel isn't burnt to 100% completion (it'd be more like 95%) and there's an increase in soot production. This soot enters the intake manifold (via the EGR valve) along with the exhaust. It combines with the oil vapour from the PCV and makes that gluggy mess ... note that EGR does NOT affect the intercooler/turbocharger in any way. It has a minor effect on performance. You might notice a small reduction in black smoke under moderate loads and perhaps a marginal (depending on your driving consistency) reduction in fuel consumption. It is, however, illegal in Australia. Detecting its removal is difficult.

An ECU remap could remove EGR commands, or in later models, remove the sensor operation detecting EGR flow. It can't affect PCV operation (that's a physical emission caused by combustion gases seeping past the piston rings during a power stroke). If blanking plates are used (particularly on older engines without EGR flow sensors, which were introduced around 2013 or so) there's no real need to modify the ECU to remove the EGR commands, because no matter how hard the ECU tries to open the EGR valve, nothing's going to get past the blanking plate anyway.