CDI EGR valves - servicing/cleaning?

[corned]

My E320CDI now has 125k on the clock, and it is going like a train. Great! However, when I read about the many EGR issues on here, I can't help but wonder if there is some mileage in having a look at my EGR and seeing if a good cleanout might be in order.

The big question is - how much of a job is this? I know it's off down the back of the motor somewhere - under the air cleaner assembly possibly?

I suppose the even bigger question is - if it ain't broke, should I attempt to fix it?

I'm not frightened about getting my hands dirty, but I am very frightened about screwing something up and ending up immobile.

Has anyone done (can anyone do) a write up or HowTo on EGR changing/cleaning/servicing?

Mine is the OM648 CDI if it needs to be specific, or would a generic guide suffice?

Thanks in advance!

 

[BlackC55]

If it aint broke......

 

[renault12ts]

You could just disconnect it and not use it. You would need to put a shunt in to fool the MAF.

 

[corned]

Thanks guys.

Renault - I'm not actively looking for something to do; I'm not that bored lol! As far as I know it is working perfectly. I was merely wondering if a good clearout might be considered as useful preventative maintenance, thus preventing it from becoming so clogged up at some point that it causes problems.

Happy to bow to Ollie's expert opinion though!!

 

[Stratman]

The following is an extract from the Honest John website on the Renault Clio 1.5 DCi Diesel.

On 1.5DCIs EGR valve should open to allow carbon dioxide, which acts as a cooling gas) into the combustion chambers when the engine is under load (>30% boost). This allows the combustion chamber temperature to drop and thus the temperature of the exhaust gases. If it sticks in the closed position the exhaust gas temperature will rise causing a) the turbo bearings to fail and b) engine oil into the induction system. This can cause the engine to run on its crankcase oil until it is either stalled or goes bang. Problems with EGR valves in Renault dCi engines are often the cause of rough running when the valve is stuck in the open position as well. In several cases turbos have blown but the EGR valve has not been replaced. Inevitably the new turbo unit will not last long

Is there a chance of this happening with our Mercs?

 

[BlackC55]

Nope.

 

[BlackC55]

Thanks guys.

Renault - I'm not actively looking for something to do; I'm not that bored lol! As far as I know it is working perfectly. I was merely wondering if a good clearout might be considered as useful preventative maintenance, thus preventing it from becoming so clogged up at some point that it causes problems.

Happy to bow to Ollie's expert opinion though!!

Your EGR is controlled by an electric motor. If the motor gets sticky or does not operate correctly you will know about it by limp mode and possible an engine warning light.

 

[allias]

Will it always trigger limp mode?

 

[BlackC55]

I can't say for certain but it is most probable.

 

[renault12ts]

Olly what are your thoughts on blanking them off by removing the power from the vacuum actuator and putting an electronic shunt in to fool the MAF? Dieselman has an interesting thread on this on the other side.

 

[radlet6]

Hello I am new here. However, having had a cRoma Diesel for two plus years I can tell you that EGR problems are quite common on all new diesels. The one in the FIAT is the same as the SAAB and Vectra C. THees can stick shut causing poor low down performance akin to severe turbo lag.

THe upshot is it seems that a sticking EGR valve affects different cars differently, and you are right, it seems that the Renault is one of the worse affected. I ran the FIAT for 5,000 miles before changing the valve with no ill effects on the turbo.

It is interesting that there is a method for blanking the valve off on the Merc, this can't be done on the FIAT.

 

[Vlad]

I think it all depends on the make of car you have....certain manufacturers seem to have better designs than other...for example...Renaults are just awful and have all manner of issues with EGR valves. We've also had to replace blocked up EGR valves on numerous Vauxhalls with the 1.9 CDTi engine....as low as 50,000 miles. Normally shows up with the engine management light coming on.

Never really had a problem with Mercs though.

 

[allias]

I di mine today. It took me 4 hours but it was worth it. EGR was working OK (acording to all reading) but it turns out the spring on mixing chamber was stuck. It wasnt easy but it was worth it. Breathes much better and there is no smoke coming out from tail pipe. Im loving this car even more. It fell so great to get this result.

Recommend to everyone who has similar problems. :bannana:

 

[GeekEcosse]

I di mine today. It took me 4 hours but it was worth it. EGR was working OK (acording to all reading) but it turns out the spring on mixing chamber was stuck. It wasnt easy but it was worth it. Breathes much better and there is no smoke coming out from tail pipe. Im loving this car even more. It fell so great to get this result.

Recommend to everyone who has similar problems. :bannana:

Did you have to take off the whole manifold to get access or could you "drop" the EGR ?

SP

 

[allias]

No - it was only chamber, cooler and egr. You can swivel them without removing manifold.