EGR Valve

[supermono]

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

[supermono]

I was thinking about blocking off the actual pipe between the manifolds by making a plate to fit between the flange/manifold one end or the other so it makes no difference if the EGR valve is open or closed...

What do you think?

SM

[supermono]

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.

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

[supermono]

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

[supermono]

So where were you when I asked about possible side effects before? Thanks for the heads up, I'll book it in to my local main dealer (a different one!) for the work to be done under warranty...

SM

[supermono]

AntMat said:

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.

You sound like you know what you're talking about but I've been doing some thinking. Since the EGR only opens on part throttle at cruise it does nothing to cool the turbo when it's working hardest -- ie at full beans.

Can you explain some more please, because this sounds like BS on the face of it.

Having said that <Bones from Star Trek mode>I'm a software engineer not a mechanic, Jim</>

SM

[supermono]

That sounds awfully petrol engine orientated though. Diesels always run very very lean or just right depending on zero to full throttle, right?

SM

[supermono]

But crucially does disabling the EGR valve increase exhaust temperatures? I can't understand why it would if it only operates on part load/throttle when little power/heat is being created by the engine.

SM