Very smelly diesel engine

[MA3TDIQ]

I have been having some serious issues with a bad smell coming from the engine bay from my 2007 plate 2.0 TDI PD170 engine.

It has done about 70000 miles and not throwing up any engine fault codes.

I have tried diesel injector cleaning with no luck.

I have stopped it from going I through the vents somewhat by sealing the engine bay with some clean rubber strips.

It's really bad when stuck in traffic lights to point where I almost feel physically sick!

Has anyone got any advice on what I should look at to solve this issue?

 

[ThePhoenix]

I get exactly the same. Same car, same year, 130K miles. It can get so severe as to choke and burn your eyes. Putting the cabin air recirculate helps some, but is no solution. I have looked for an answer many times and not found one.

I am now of the opinion it is gas escaping from a worn swirl flap shaft. (see my post - A3 2.0 TDI inlet manifold - of an hour ago) and am planning to seal it this afternoon. At your mileage I would guess you have the same wear with oil accumulating near the flap actuator at the left side of the inlet manifold. If you dont have this fault then I am at a loss as to what it might be, as your issue seem so similar to mine.

 

[MA3TDIQ]

I was thinking it may be a build of carbon in the EGR valve and inlet manifold-would cleaning these out solve issues with smells?

I don't know what to do now tbh-I don't want to take it to Audi and pay an absolute fortune to have them investigate it.

I guess a good independent garage might be the way forward?

Any other suggestions that anyone can think of or had similar problems?

 

[Gazwould]

Renew activated charcoal pollen filter.

 

[MA3TDIQ]

Don't think the pollen filter will sort out the problem with exhaust smells in the engine bay

 

[ThePhoenix]

I was thinking it may be a build of carbon in the EGR valve and inlet manifold-would cleaning these out solve issues with smells?

Done both of those things; still the same smell. I had an independent at the bottom of my road do the last service and when I went to pick up the car he and a pal of his who is a diesel guru (apparently) were pouring over the engine in their car park, as they couldn't stand it running in the workshop because of the acrid fumes. He had called his diesel expert to take a look, as he had never experienced anything like it. They were both at a loss to explain it, as have forums and others I have asked been. If my swirl shaft 'repair' doesn't solve it, then I don't know what to else to try.

As you can imagine I am very interested in the responses you get here.

My repair won't be finished now until Monday, but I will report back with the results. BTW is your swirl shaft worn and are tar-like deposits being spat out the left-hand end of your inlet manifold?

 

[MA3TDIQ]

Would you be able to show a picture of what you mean by that? I can't see obvious deposits being spat out but I think the smell is coming from the top of the engine...
I'm actually on the verge of trading it in it's that bad-the rest of he car is still in mint shape

 

[ThePhoenix]

Remove the engine cover and look to the left end of the inlet manifold. ( I think you may be able to see it without removing the cover - not at the car at the moment)

You will see this. The clip to the left of the the area ringed in yellow is holding the cam-belt cover, Just above the yellow area is a round vacuum actuator. The rod that it drives can be seen disappearing behind the cam-belt cover, The hidden end of this rod controls the swirl valves. If your shaft is worn (w'hey!) looking around this area you will see oily deposits, or if it is really bad, tar-like splatter around and about.

Not good for you, but I hope you have it, because as I have said I am banking on this being the source of our problem. Please let me know what you discover.

 

[MA3TDIQ]

Remove the engine cover and look to the left end of the inlet manifold. ( I think you may be able to see it without removing the cover - not at the car at the moment)

You will see this. The clip to the left of the the area ringed in yellow is holding the cam-belt cover, Just above the yellow area is a round vacuum actuator. The rod that it drives can be seen disappearing behind the cam-belt cover, The hidden end of this rod controls the swirl valves. If your shaft is worn (w'hey!) looking around this area you will see oily deposits, or if it is really bad, tar-like splatter around and about.

Not good for you, but I hope you have it, because as I have said I am banking on this being the source of our problem. Please let me know what you discover.

I have just had a chance to look at my engine a bit more closely and there is definitely some oil sitting in that area!

Did you manage to solve it by replacing the shaft of that controls the swirl valves?

Cheers!

 

[ThePhoenix]

I think I've managed to do a reasonable repair in the swirl flap shaft. The bad news is that the acrid smell still exists.

I am of the opinion that this must be exhaust gas escaping before the catalyst gets to work on it, but for the life of me (and the local mechanic, and the MOT man) I can't find the source. I can't imagine that it is just you and I that are the only two to have encountered this issue; and on the very same model and year too.

If you discover anything then please let me know and I will do likewise.

Cheers.

 

[MA3TDIQ]

I had some more thoughts about this issue - maybe I'm talking nonsense so please correct me if I do.

I installed a TDI tuning box about a month after I got the car- it was great extra power and improved throttle response.

About half a year later I started to notice an emission light come on when I was driving so I was getting a little bit worried the tuning box wasn't working properly. So I disconnect the box and the emission light went off again. As soon as I would plug the box in again the same thing happened - the emission light came on again. So I investigated a little bit more and actually realised that the cable connecting my tuning box to the ECU had melted!! This may have been the result of increased engine temperatures when using V Power diesel.

May thoughts are - Has the tuning box malfunction caused an issue with my ECU? Is there a way to reset/retune it?

Could this be the cause of the smell and rough running?

Cheers!

 

[sliced]

Have you had your exhaust system checked?

 

[MA3TDIQ]

pretty sure its not the exhaust as the smell comes from under the bonnet...

 

[enc]

Total shot in the dark ...

Leak at fuel pump ?
Exhaus manifold t gasket leak ?
Exhaust Union leak
Clogged egr ? Lots of oil around egr

Sounds pretty serious ... Can you smell fumes on your clothes after being in the car ?

 

[MA3TDIQ]

Total shot in the dark ...

Leak at fuel pump ?
Exhaust gasket leak ?
Exhaust Union leak
Clogged egr ? Lots of oil around egr

Thanks for that,

It had a new fuel pump a couple of months ago along with an injector. I had an dependent garage look at my car and they said my EGR looked quite new also i guess that leaves exhaust gasket and exhaust union as possibilities amongst others -how would i diagnose those problems?

Strangely enough I have a VCDS and never has it thrown up any fault codes with the engine...

If it doesn't throw up any codes does that mean the problem I have isn't severe?

 

[Rhyso]

If the exhaust gases are escaping BEFORE they get to the exhaust then the logical place you will smell them is under the bonnet

No fault codes simply mean that the fault doesn't exist near a sensor for it to get its knickers in a twist and throw up either a code or a management light

 

[MA3TDIQ]

Still getting fumes and its driving me insane - can't see any oil leaking anywhere. Anyone have any further ideas? The garage I have been to have no clue!

 

[aqibi2000]

Has your DPF been removed on the PD170? I have the same issue I think

 

[MA3TDIQ]

Still has original DFP but never been a problem as never gone into limp mode so I never thought the need to remove. Exhaust gasses seem to be escaping under the bonnet not under the car so would that not indicate a different issue to the DPF?

 

[aqibi2000]

I was thinking more along the lines of a bad reweld of a dpf or leaking pipe

 

[killphil]

Renew activated charcoal pollen filter.

some people just have to put in there 2 pence worth. please dont make pointless comments as it clogs up the forum for serious people.

 

[Gazwould]

Breathing cleaner air is serious .

Exhaust fumes from manifold or whatever is going to come into the cabin , and there's a very good filter available to block out NOx and particulates .

Obviously he has to solve the issue .

 

[samuelh_888]

some people just have to put in there 2 pence worth. please dont make pointless comments as it clogs up the forum for serious people.

You say to a 4 year old post on a thread that hasn’t been active for over 2 years

Have you managed to solve the same issue as the OP?

 

[aqibi2000]

Root cause of this is the engine timing. Went though months of the same issue on a PPD170 and replaced every possible gasket, alongside using a Carbon activated cabin filter.