Discussion
Our family stinkwheel (1.9jtd doblo) is showing all the signs of a stuck EGR. After unsuccessfully getting the local fiat agent to fix it under warranty yesterday (another story!) I've decided to do the simple job myself.
I'm in two minds though. Should I buy another EGR valve (can't be arsed to clean the old one for 5 minutes more use) and then another one in a couple more years etc, etc, or just make up a little steel plate to fit between the flange on the connecting pipe and the inlet manifold to disable the function?
As far as I understand it, the EGR valve is entirely to do with emmissions so is of zero use and blocking it off has no ill effects. Am I right?
What to do?
SM
I'm in two minds though. Should I buy another EGR valve (can't be arsed to clean the old one for 5 minutes more use) and then another one in a couple more years etc, etc, or just make up a little steel plate to fit between the flange on the connecting pipe and the inlet manifold to disable the function?
As far as I understand it, the EGR valve is entirely to do with emmissions so is of zero use and blocking it off has no ill effects. Am I right?
What to do?
SM
EGR valves feeds the engine its own sh*t. Took the EGR off the O-series perkins diesel in our elderly Maestro yonks ago and it improved the engines response and helped fuel econmy too. Could still produce huge clouds of Black sh*t on demand when clogging it (those O-series could smoke some!) - great for upsetting tailgaters 
That was on a mechanical pump diesel and so had no impact on fuelling.
If your Diesel is common rail with management of fuelling (and probably a closed loop input from downstream in the exhaust (giving input into the EGR in the exhaust) it may cause problems. See if you have an electric EGR valve - should be simple to check for wiring loom too/from.
That was on a mechanical pump diesel and so had no impact on fuelling.
If your Diesel is common rail with management of fuelling (and probably a closed loop input from downstream in the exhaust (giving input into the EGR in the exhaust) it may cause problems. See if you have an electric EGR valve - should be simple to check for wiring loom too/from.
On the scabby Maestro TD we took the valve out completely. 2 x blanking plates in made up in 4mm plate + 2 new gaskets. Job done.
If your EGR is Vacumm operated (per the MAestro) you'll have no bother. Just check it isn't an Electric EGR that has part open conditions at certain throttle/load conditions on your modern common rail unit.
If your EGR is Vacumm operated (per the MAestro) you'll have no bother. Just check it isn't an Electric EGR that has part open conditions at certain throttle/load conditions on your modern common rail unit.
Be careful blanking this off can trip a fault code error on some systems(dont know if your model is affected)the transit pushrod 2.5 diesels love it blanked,so do the earlier peugeot & citroen XUD engined models,if you can cap it off just do it,smoother running and cleaner intake manifold & unchoked inlet ports are just two of the benefits.EGR
supermono said:
Our family stinkwheel (1.9jtd doblo) is showing all the signs of a stuck EGR. After unsuccessfully getting the local fiat agent to fix it under warranty yesterday (another story!) I've decided to do the simple job myself.
I'm in two minds though. Should I buy another EGR valve (can't be arsed to clean the old one for 5 minutes more use) and then another one in a couple more years etc, etc, or just make up a little steel plate to fit between the flange on the connecting pipe and the inlet manifold to disable the function?
As far as I understand it, the EGR valve is entirely to do with emmissions so is of zero use and blocking it off has no ill effects. Am I right?
What to do?
SM
I'm in two minds though. Should I buy another EGR valve (can't be arsed to clean the old one for 5 minutes more use) and then another one in a couple more years etc, etc, or just make up a little steel plate to fit between the flange on the connecting pipe and the inlet manifold to disable the function?
As far as I understand it, the EGR valve is entirely to do with emmissions so is of zero use and blocking it off has no ill effects. Am I right?
What to do?
SM
Simple answer is to tell the dealer to put some effort into fixing the problem.
If the engine has a diagnostic function the use of a blanking plate could be detected and limit the engine performance. EGR should also improve part load fuel economy plus give emissions benefits, so it's probably best to have it working correctly.
On diesels i can not see EGR improving power,they only improve emmissions at high engine speeds,ie motorway speeds,round town big no no,just contaminates the fresh inlet charge with crap.Just another manafacturers were doing how bit for emmissions gadget,they do have benefits but not in the world these cars live in,Audi/vw engines suffer bad inlet contamination because of the EGR system,to the point where the inlet manifold runners reduce to nothing,how can that improve running and emmissions
This is a common rail Diesel and the engine management system expects the EGR to be there and working. There is no feedback to the engine management system with regard to the position of the EGR valve. Blanking off the EGR valve will help confirm if it is faulty but I would be wary of leaving it in this state for too long, personally.
When checking the EGR make sure that the valve spindle AND the solenoid spindle move freely. You will need to detach the solenoid to do this.
When checking the EGR make sure that the valve spindle AND the solenoid spindle move freely. You will need to detach the solenoid to do this.
GavinPearson said:
Simple answer is to tell the dealer to put some effort into fixing the problem.
If the engine has a diagnostic function the use of a blanking plate could be detected and limit the engine performance. EGR should also improve part load fuel economy plus give emissions benefits, so it's probably best to have it working correctly.
If the engine has a diagnostic function the use of a blanking plate could be detected and limit the engine performance. EGR should also improve part load fuel economy plus give emissions benefits, so it's probably best to have it working correctly.
The dealer in question became rather unprofessional. Even though the car was exhibiting textbook EGR valve fault (as I've now confirmed -- I blanked it off and it's now spot on), he decided to waste two hours thrashing the car up and down the road ("it was smoking, it's never gone over 40mph" was his "expert" assessment) and cleaning the exhaust manifold. For some reason when I told him I wasn't paying for this lunacy he got all upset.
I may take it to another dealer, but since there were no faults recorded already (and it's been very wrong for a couple of hundred miles) I'm doubtful that EGR function is actually monitored. Plus I'm not comfortable with a)pumping exhaust gas through the engine and b)fixing something that'll only go wrong again in another couple of years' time for absolutely no good reason.
SM
A quick update for those interested. I put a plate on the inlet manifold side of the pipe blocking off the faulty EGR valve. Immediately the car worked the way it should, though for the test drive it belched plenty of black shite out of the exhaust on WOT. But soon settled down and has been fine since. About 500 miles on no engine light, no running problems whatsoever.
So far I'd recommend it as a free fix to the crappy EGR / Treehugger valve problem.
Cheers
SM
So far I'd recommend it as a free fix to the crappy EGR / Treehugger valve problem.
Cheers
SM
No doubt I shall be shat upon from a great height for suggesting this but there is a thread on Parker's in the FAQ Forum. I make no apologies for the fact that I wrote it.
The EGR valve has a well defined function in modern common rail TDs. It's malfunction can, given time, cause a turbo to fail. TD engines, particularly TWAT (Thin Wall Alloy Technology) ones like Renault's 1.9dCi, rely on the introduction of NOx as a cooling gas to cut emissions. Failure to do so will increase both the temperature of the oil and the exhaust gasses. This, in turn, may well hasten the demise of the turbo.
The EGR valve has a well defined function in modern common rail TDs. It's malfunction can, given time, cause a turbo to fail. TD engines, particularly TWAT (Thin Wall Alloy Technology) ones like Renault's 1.9dCi, rely on the introduction of NOx as a cooling gas to cut emissions. Failure to do so will increase both the temperature of the oil and the exhaust gasses. This, in turn, may well hasten the demise of the turbo.
When you asked the question before I do not believe that I was a member of this august forum. Unhappily for some, though I shall no doubt have to continue with verbal abuse and bullying, I shall remain a member and try to contribute something useful as I do on a number of other forums and elsewhere
!
! You may not believe this Anthony but this comment isn't designed to disagree with you.
I am dubious of the benefits of NO or N2 as a cooling means as they are coming from the exhaust side and being fed in to the inlet side, (also not heard of t
t either but if it exists brilliant nickname!).
I would suggest the chap watches his water temp closely as his car won't have oil temp gauge, and if it does rise noticably then he replaces it (see I do agree with you at times) but really don't think he will have any major issues with turbo failure due to direct heat as they are fine on petrol engines which run hotter exhaust gasses.
I am dubious of the benefits of NO or N2 as a cooling means as they are coming from the exhaust side and being fed in to the inlet side, (also not heard of t
t either but if it exists brilliant nickname!). I would suggest the chap watches his water temp closely as his car won't have oil temp gauge, and if it does rise noticably then he replaces it (see I do agree with you at times) but really don't think he will have any major issues with turbo failure due to direct heat as they are fine on petrol engines which run hotter exhaust gasses.
Why therefore I wonder is the % rate of turbo failures higher on diesels than on turbos? What do you think Oliver?
My reckoning is that the amount of condensate produced is higher in TDs than in PDs. UK traffic conditions are not condusive to well blown out engines and this is far more so with diesels - just watch your black cabs letting loose on the M4 after the flyover
. Almost as bad as a WW1 destroyer on convoy duty! Whilst the heat generated in the combustion chamber of a petrol engine is higher, the heat loss is more rapid and I have noticed that coolant temperature on a diesel can run higher than on a similar model with a petrol engine.
Again this could be down to malfunctioning EGR valves which unfortunately have a tendency to stick closed rather than open
.
Mechatronic EGR valves are linked into the EMS so that if the valve is disconnected, the EMS could think that there is a malfunction and possibly cause the car to go into "limp home" mode.
It is very easy for dealers to check EGR valves as Pierburg has produced a number of testing tools for different makes. These are available and should form part of a main dealer's armoury.
My reckoning is that the amount of condensate produced is higher in TDs than in PDs. UK traffic conditions are not condusive to well blown out engines and this is far more so with diesels - just watch your black cabs letting loose on the M4 after the flyover
. Almost as bad as a WW1 destroyer on convoy duty! Whilst the heat generated in the combustion chamber of a petrol engine is higher, the heat loss is more rapid and I have noticed that coolant temperature on a diesel can run higher than on a similar model with a petrol engine. Again this could be down to malfunctioning EGR valves which unfortunately have a tendency to stick closed rather than open
. Mechatronic EGR valves are linked into the EMS so that if the valve is disconnected, the EMS could think that there is a malfunction and possibly cause the car to go into "limp home" mode.
It is very easy for dealers to check EGR valves as Pierburg has produced a number of testing tools for different makes. These are available and should form part of a main dealer's armoury.
I don't know, I would guess it could have something to do with more low down work which results in the turbo frequently stalling and having to wind back up which must be the most stressful part of a turbo's life, plus dirtier exhaust gases clogging them up, and lack of care from owners (switching engine straight off after run, thrashing from cold) dirtier oil, there are loads of possibles, but I don't know.
I don't think that letting the engine run on for a bit with a TD will help the turbo as there is less likelihood of "coking" due to lower bearing temperatures. I would still advocate a 100% synthetic oil though as it will further reduce the chance of turbo damage.
It is a well recorded fact that Renault, BMW and VAG have all had major problems with turbo failures in their TD lumps. It is rumoured that some ECUs have been remapped to account for UK road conditions. Who knows?
But my maxim is:
Clean Oil + Clean Air ~ Cooler Oil Less Aggrevation
equates to
Coca ~ Cola!
It is a well recorded fact that Renault, BMW and VAG have all had major problems with turbo failures in their TD lumps. It is rumoured that some ECUs have been remapped to account for UK road conditions. Who knows?
But my maxim is:
Clean Oil + Clean Air ~ Cooler Oil Less Aggrevation
equates to
Coca ~ Cola!
Edited by AntMat on Wednesday 4th April 20:45
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