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View Full Version : Audi A6 1.9 TDI 110, W Reg getting noisy



tattyman
28-01-2007, 09:14 PM
I've just joined the forums, so apologies if the answer to this is elsewhere, I've searched before I've asked the question but come up blank.
I have an Audi A6 1.9 TDI, 110 BHP. It's a W Reg. I've had it for 2 years and overall I'm very pleased with it. I'm sure though that recently it's started getting noisier, both in terms of diesel "clatter" and also more of a deep note to the engine (like a blowing exhaust, but the exhaust is fine) It also occasionally "coughs" if I come out of a bend and floor the accelerator, accompanied by a little smoke just after the cough.

Any ideas anyone? I wondered if it was the MAF but MAF faults seem to be a bit more extreme (i.e. no power at all)

onzarob
28-01-2007, 09:27 PM
I would bet on the MAF as they can fail intermitantly. explaining the cough as you put it. If you get the fault codes read. It can be confirmed by a MAF implausible signal or intermintant short/open circuit.

Rob:D

tattyman
28-01-2007, 09:30 PM
Thanks onzarob.

Would the faulty MAF explain the extra noise? Every review I read of an A6 TDI of similar age to mine goes on about how smooth and refined the diesels are. My just doesn't feel that "smooth and refined"

onzarob
28-01-2007, 09:42 PM
What sort of mileage has it done. they are smooth, but not the same as a petrol. you may find if its high miles then the tappets are a little noiser when cold. And i have read that the engine mounts tend to go down hill on high milers. mines a little lumpy, but its got 130K and still does 53mpg. so i don't worry too much.

Rob:D

tattyman
28-01-2007, 09:55 PM
It's only got 88k on the clock. I do get the tappet noise you mention when it's cold (noticable this time of year), on starting up , but that settles down quite quickly once the oil starts to flow around.

It sounds harsh in low gears when under hard acceleration. It certainly pulls ok (apart from the odd cough as mentioned earlier)

The other thing I've noticed is that it's quite smokey in 1st and 2nd gear (looking in the rear view mirror at night when accelerating fast I can see smoke shown up by the following car's headlights), but once you get to 3rd gear the smoke stops.

VW Techniker
29-01-2007, 01:48 AM
It's only got 88k on the clock. I do get the tappet noise you mention when it's cold (noticable this time of year), on starting up , but that settles down quite quickly once the oil starts to flow around.

It sounds harsh in low gears when under hard acceleration. It certainly pulls ok (apart from the odd cough as mentioned earlier)

The other thing I've noticed is that it's quite smokey in 1st and 2nd gear (looking in the rear view mirror at night when accelerating fast I can see smoke shown up by the following car's headlights), but once you get to 3rd gear the smoke stops.

Hi,

Sounds to me like you have a build up of carbon in the intake manifold, unusual engine noise and some smoke are caused by this fault. Pull off the intake hose and check inside the manifold for a thick build up of oily carbon. If present the engine will not draw in enough air and will cause diesel knock... Take no notice of MAF readings until you have checked this first.

onzarob
29-01-2007, 12:58 PM
I must admit cleaning the intake manifold is on my list of thing to do. I was planning to do this before diagnosing any other reasons for a smokey back end.;)

Rob:D

tattyman
30-01-2007, 01:37 AM
I'll take a look this weekend (won't have time before.) Assuming it is gunked up, how easy is it to clean?

mr audi
05-02-2007, 09:41 PM
Hi, take a close look at the intake pipes. the small one about 4 inches near the top of engine tends to have small split.