EGR Valve and effects

[jc_geddes]

Morning all,

My egr valve is broken - there is oil every where and it is making some funny noises, it sounds like the noise is coming from the back of the car but when you open the bonnet with the engine running and warm, then it is defiantly coming from the egr valve - the noise by the way is a low thudding from outside of the car - under the bonnet its more high pitched with the occasional duck thrown in.

I am going to get the parts to fix this, but I was wondering if this was also causing my passat to burn oil under boost for the first 5 mins of a cold start. I have read some where that a failed valve can cause oil to enter the inlet system.

So the question is what other, effects, issues could a split diaphragm on an egr valve cause?

Cheers

John

[snapdragon]

I don't see how it can let oil into the inlet as it has nothing to do with oil and is nowhere near any oil. It operates at idle and low load and it opens a valve and allows exhaust gas into the inlet air stream to reduce the oxygen percentage in the air charge. This in turn reduces the combustion temperature (only slightly) to below the thresh-hold temperature at which nitrogen and oxygen combine to form NOx (which is classed as a pollutant by the government.

The valve has a plunger which is pulled by the force of vacuum on a diaphragm. The diaphragm ruptures when old and can affect operation and make funny noises as it acts as a reed does in a trumpet.

You should get it fixed and in the meantime, unplug the rubber vacuum hose and blot it with a section artist's paintbrush handle or similar, as the vacuum system will now be drawing in smoke and it could damage/dirty up N75 solenoid valves etc....

[jc_geddes]

Okay,

but where does all the oil that is around the egr valve come from?

[kenney]

I take it this is a PD engine we are talking about and the oil is in the charge air system and is not unusual,Excess oil is a sign the turbo seals are leaking.

[Nodrog71]

I've got a 2004 v6 tdi with 106K on the clock and recently have noticed that car feels like it's lost 20 bhp and mpg have dropped to 35 on a run (usually 40/45). Also first thing in the morning I've noticed that some smoke appears from the exhausts for a short while. Now I thought that the MAF was faulty, reading this thread seems the EGR value might also be part of the problem. Just where do you go to find out exactly what the problem is?

[kenney]

You should start by having a fault code read

[Nodrog71]

Well, I managed to get to the root of the problem. Drove back from Dartmoor, car very, very sluggish and massive low mpg. Car started to make a dreadful noise from the front of engine, AA towed to BH Auto's (Binfield) who diagnosed that both tensioner and guide bearings had broken on the cam belt - this in turn meant that the timing was out. So I've had to pay for another cam belt replacement, which BM Autos have carried out.
I had the cam belt changed at 78K (car now 106K) with an alledged genuine VW cam belt kit, so I'm in the process claiming against VW Autos (Fleet) and VW parts.
BM Autos did a diagnostic test on my car and found no fault codes and I am happy to report that my car is running very well and mpg back to 40/45 on a run.