Help with loss of power, noise and smell in cabin

[Mr.Linnet]

Just wondering whether anyone could offer some help and advice please.

2006 VW Golf MK5 2.0 diesel with around 120,000 miles on the clock. After returning home after a 80 mile journey the car seemed to lack the normal amount of power. Having used the car since there is now a distinct lack of power when accelerating and this is accompanied with a sound like a whoosing noise when the accelarator pedal is pressed hard, although once over about 2000rpm the car drives reasonably well. All this is coupled with a smell of what seems like exhaust fumes entering the cabin especially when the air con is operated.

I have checked and replaced the air cleaner element. I have also had a quick check of the air intake hoses for splits but cant seem to find any.

I read somewhere that a dodgy plug connection to the MAF sensor could also be the cause. Today I checked the MAF sensor, now after dis-connecting the plug and refitting it the eml has illuminated.

Do I need a diagnostic reader to turn off the eml?

I have also read that the egr valve might be worth cleaning, although this was changed around 8 months ago and in my opinion I would have thought the engine would be running rough in general but it ticks over nicely at idle and doesnt smoke.

Would be grateful for any suggestions as to the possible causes and rectification options to cure the hesitation/flat spot, smell and noise.

Many thanks in anticipation.

[VAG-Abound]

What engine is it? BKD perhaps?

Thinking about the work I did on our similar car, a split / opening in the EGR pipework would reduce the flow in the turbo (and hance affect performance) while also letting exhaust fumes into the cabin air intake area. What was the source of the replacement EGR valve? I'd be considering mechanical failure there, especially if non-VAG.

[Mr.Linnet]

Thank you very much for your reply

The engine is a BKD, it doesnt have a dpf. The egr valve was a pattern part.

I partially eliminated the egr valve because I assumed if it was playing up the engine would probably run rough all the time rather than just that one flat spot/hesitation area. However your comment makes complete sense and worthy of further investigation. As it happens I have just checked before writing this message and taken the car for a short drive in the hope that the eml would go out if there is no fault ( only came on after I unplugged and refitted the MAF sensor ) but the eml is still illuminated. I checked under the bonnet after switching my engine off and there is definately a noise (this is a different noise to the one when trying to accelerate) coming from the egr valve, it lasts about 10 or 15 seconds and sounds like the sound a telephone makes when you dial an unobtainable number, this is followed by a distinct clunk as if a valve is shutting. Could this help diagnose the problem?

Waiting for the rain to stop here today before progressing further.

Many thanks again

[Mr.Linnet]

Just a brief update to keep any interested informed.

EML light turned off and no fault codes to clear.

Have taken the EGR valve off, not too bad condition but obviously took the opportunity to clean it up before refitting. Tried the car up the road and still the same. Still has flat spot accompanied by noise similar to that of either sucking in or blowing out air. Once passed the flat spot the car performs well with no noises.

Will be checking the air intake hoses next and intake manifold ( wondering if intake gasket has failed? ).

[philipharmes]

If you have exhaust fumes then the problem will probably be on the exhaust system somewhere.

Check for leaks at the exhaust manifold/ downpipe, turbo & EGR.

The EGR isn't open all the time, so a leak from there might only occur under certain driving conditions.

It can sometimes be easier to find leaks at night, when a torch beam can pick out the exiting fumes.

[Mr.Linnet]

Thank you for taking the time to reply and the suggestions you raise.

Never thought about checking at night time for leaks......I`ll be trying that later

[Mr.Linnet]

VW Golf soot.jpg

Photo taken of water cooler behind the rocker cover ( after removing the intake pipe ). Top and sides covered in soot but gave the top a wipe but left soot on the sides to take photo. Didn`t explore any further as I didn`t want to disable the car without getting some spare parts first. I assume the soot must be coming from exhaust manifold gasket which sits directly below the water cooler.

Will be popping to get a replacement mainfold gasket tomorrow, can anyone think of anything else I might need?

[VAG-Abound]

Do you mean the main exhaust gasket between engine and manifold that is fitted on turbo? Or the smaller "diamond ones that sit at each end of the of the take pipe for EGR and could also be leaking?

Replacing main gasket will be a bit of a phaff as it is essentially turbo out, along with a few bits of intercooler pipe, turbo oil line, heat shields, etc. Nuts that keep turbo in place are specced for renewal rather than reuse IIRC, although reuse is very common.

So well worth double checking the smaller ones first as they are simple to get to, if a bit fiddly depending on which side you come from. I recall finding a short spanner / 1/4" ratchet useful for loosening the nuts on the turbo side. Not sure if the "top" bolts were spline or hex - again awkward to reach. I think I found going from below with a flexi-shaft screwdriver worked well on those after cracking the tension from above.

[Mr.Linnet]

Thank you very much for your continued interest in this thread.

I have ordered both a main exhaust gasket and the two smaller "diamond" shape ones you mentioned in your reply. I also appreciate the tips you enclose regarding carrying out the repair. I won`t know which ones I will need until I start stripping things down but here is hoping it is the two smaller ones