Buzz at idle

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Mark Paxman

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My new TDi has a buzz/rattle at idle when cold starting (0 deg C or less). It goes away if you rev the engine even a little, and then returns when it drops back to idle. It disappears when the engine warms up.

I don't think it's the "nominal" injector noise, hey it's not the quietest engine in the world when cold.

Any suggestions? I can see a nightmare taking it to a dealer because (a) it's intermittent and (b) I'd have to leave it overnight so they can cold start it.

I'll take the bonnet off on Saturday morning and have a listen, wake the neighbours up.

Cheers
 
It probably normal - piston slap, tappit noise, lack of oil etc when you start the engine from cold. Mine has been noticeably noisier this last few days, its been around 0 degrees most mornings. Once warmed up no problems.
 
Mine does exactly the same thing. My previous TDi didn't. Consolation is it goes within a couple of minutes. I must have got used to it because I can't remember hearing it recently.

Shaf

Nov 2002 TDi Sport, Silver,Black/grey interior,climate. Replaced previous Mar 2001 TDi SE
 
I get this too on my TDi. Its a kind of 'clacking' noise that seems to eminate from the central windscreen heater vent.
It only makes the noise when cold, and only when the engine is doing anything. By this, I mean that if you depress the clutch and coast along the noise stops. It also disappears when the engine has got some heat in it.

All of this lead me to believe that it is noise coming from the EGR valve. I mean, if the EGR valve does what it is supposed to do, then it would make sense that I can only hear it when the engine is cold, and exhaust gases are being created in any reasonable quantity.

Does this sound feasible? I certainly wouldnt like to think that it its caused by piston slap, tappits, or a lack of oil. If it were any of these things then I wouldnt expect to see many TDi engines living longer than a few thousand miles!

Phil. TDi Sport, silver, with Climate and OpenSky.
 
If the noise you describe is the EGR valve then that is very unusual. I went through several visits to the dealer regarding EGR valve problems - but all of them were only when the engine was fully warmed up, never when it was cold.

By the way, if you do have an older model of A2 (mine was born June 2001), then there is a modified EGR valve now available which I have had fitted under warranty and has completely eliminated the problem I had.

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I also have the cold TDI Problem but it is is not consistent on cold days
 
Hmm... I thought the EGR valve is there to pass gases around the engine a second time to improve heat efficency? Hence I would be hearing it in action when the engine is cold, but not when the engine has warmed up?

The clacking I hear seems to be in time with the stroke of the engine. That is, as I increase revs, the clacking 'speeds up' also. This again made me think of the EGR...

I'm getting concerned now. Should I pay the dealer a visit?

Phil. TDi Sport, silver, with Climate and OpenSky.
 
Phil, the clacking you describe seems to be different to the buzzy/rattle as this is only evident on tickover and goes if the revs are increased, whereas yours increases with revs. It does seem to come from somewhere in the general direction behind the air vents in the centre console.

Shaf

Nov 2002 TDi Sport, Silver,Black/grey interior,climate. Replaced previous Mar 2001 TDi SE
 
My old Saab made that noise when the (petrol) injectors were knackered so it's probably injection noise. It ain't quiet on a winter morning is it! Fortunately the insulation on the new ones seems pretty good so it's only the neighbours that get upset. At least they don't get a windowful of diesel smoke like they did with the old car.

Thanks for telling me it's normal, it lowers the blood pressure a little since dealing with dealers is my least favourite way to spend an afternoon
 
It's really bugging me, I went to wave my girlfriend off the other morning and the buzz was really loud. When the engine's warm I can make the same noise by pulling away at idle ie lifting the clutch without pressing the accelerator. Bzzzzzz. Sounds like a metal plate or something vibrating. Seems a bit rubbish for a new, quieter TDi.
Aaarrghhh! Might take it in to Audi but that's a lot of pain
 
It's bugging me too. My A2 does exactly what you describe in your last message: vibrating metal plate below the car. AND I also have/hear it when cruising at a steady speed with RPM's between 2000 and 3000. Very very annoying and also really silly for a car that should have Audi quality, shouldn't it?

My dealer already looked at it quite extensively for over half a day. They were unable to find anything out of the usual (but they did hear the sound. I and they can reproduce it without a problem). They gave me back my car with apoligies, probably hoping I'd leave it until the next service. But it's been doing it for 23000 km now and it will not go away.

I'm trying to make an appointment with them today. Hope they have time. I'll follow up with detail on the solution (if any)... That gives you something to ask for when bringing it in too.

--
(2003 Silver 1.4 Tdi Exclusive(SE), 95bhp/235Nm chiptuned by ABT, black interior, sport seats, heated mirrors, JVC KD-SH909RB cd-receiver, Infinity Kappa 63.1 + Vifa on-dash tweeters, 12" Subwoofer on 300w Amp)
 
Swiv, best of luck to you, keep taking the blood pressure tablets & let us know what happens
Do you reproduce it in the same way (load the engine at idle?)
Anyone else out there with the same sound?
Even better anyone who's had it FIXED!?
 
There's a small difference in when we both experience 'the sound'. Maybe I misread your post a little. But my 'sound' is present at rpms _above_ idle, more towards 2000-3000. Cold or warm, but worse when cold.
I especially hear it these days when half idling around town, accellerating slowly.

It is really loud and everybodt that I explain it to, hears it. I think yours is a bit more subtle (since we were talking injector noise and the like before...)

Well, whatever the source, I'll keep you posted with the solution for 'my sound', whenever found!

--
(2003 Silver 1.4 Tdi Exclusive(SE), 95bhp/235Nm chiptuned by ABT, black interior, sport seats, heated mirrors, JVC KD-SH909RB cd-receiver, Infinity Kappa 63.1 + Vifa on-dash tweeters, 12" Subwoofer on 300w Amp)
 
Swiv, you obviously don't have your 300W amp loud enough ;)
 
Exhaust system?


Steve - 2002 1.4SE petrol, Silver, black/black interior, Then an identical replacement 2003 A2. Now a Toyota Corolla 1.6 T-Spirit
 
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