A3 2000 W Over Revving, then stalls, wont start again

[marmitejar]

Hi,

I wonder if anyone has had this same problem. I had it happen a while back, the car (Audi A3 SE 2000 W reg) suddenly starts over revving, I pull in, and the only way to stop it revving like mad is to turn off, or sometimes it just stalls itself (particularly at junctions)before I get to pull in. My garage recommended a throttle body clean. I had this done and then the car seemed to rev high all the time, but at least it never stalled. It went OK for 6 months or so and now I am back to the erratic over revving and stalling. It also takes a lot of turning over to get it started again. Anyway, I rang about a new throttle body and they quoted £550!! As my car is a 2000 W, it isnt worth paying that. I found one at the breakers (warranted for £60) but the garage say that it is likely to reject the different throttle body and have software problems??? I am now stuck, because no way am I paying £550 (which may not even solve the problem). I would like to try the breakers one, but could I end up with the car more knackered than it is now, if it rejects it? At this rate I may as well just sell the car for £500 and see if someone can sort it and get a bargain. Thanks for any help.

[zollaf]

i think you should find a garage that has half an idea of what they are talking about myself. just my opinion like.
what fault codes does it come up with when they plugged their computer into it.

[marmitejar]

Ok. I had a diagnostic last year when it first played up, and it said it found fault with IDL CONTROL VALVE. I had the throttle body cleaned and reset. Other faults are coolant sensor and lambda probe. My feelings are though that after I had the throttle body cleaned, it did change how the car was working. It didnt stall afterwards, I got 6 months without it stalling but now it is back to how it was. To me (Im no mechanic) that points to a fault with the throttle body. I just dont understand why I cant just have a warranted second hand one fitted without the car 'rejecting' it?? Can you not replace with one other that a 'new' one costing £400? Thanks a lot for your help.

[NickPicks]

If you replace the throttle body, I can't see why the engine management would 'reject' it. I'd check it either comes off the same engine code, or has the same part number. You will probably need to do a throttle body alignment with vcds.

I agree with zollaf's idea of finding a garage who know what they're talking about. Where abouts in the country are you?

Have you replaced the coolant temp sensor and lambda probe? What were the fault codes? (each of them have a number to look up for advice on the ross-tech wiki).

It's not necessarily a problem with the throtle body(TB). If there's something else causing the engine to over or under fuel, cleaning the TB may have just helped enough to get it running. The ambient temperature has recently gone up significantly, which might be pushing the problem over the edge.

You also need to tell us your engine code, as this is very helpful to know what car you're talking about. This will be a 3 digit code on the sticker in your service book, or in the spare wheel well - something like AGN.

I think your first action should be to have a code read. This'll probably cost you about £30, unless you live near me who'll do it for free. This'll tell you if there's any faults that the engine management wants fixing. I'd also be inclined to check that the throttle cable operates freely and doesn't get stuck. I'd also check the inlet pipework for any leaks letting air in to bypass the throttle body.

When you say 'revving like mad', what is the actual engine speed on the rev counter? If it's upto 2000, it might just be the engine thinking it needs to fast idle.

[marmitejar]

Hi,

The engine code is AKL 814670.The fault codes were 537 (P0219) Lambda Control Upper limit Stop Value (Sporadic Fault) and 522 (P020A) Sender for coolant temperature - G62 Implausible Signal (Sporadic Fault). I have not replaced the sensor and probe. The garage seemed adamant that it was the throttle body needed cleaning and now replacing. I guess what it comes down to is as like I said, the parts are just a total rip off (£400 for a new throttle body vs car worth about £750) when you cant fit secondhand parts. Gonna try and talk with them and find out why you cant do this. Thanks for all your help, appreciated.

[Crasher]

First rule of repairs and I am seeing this over and over and over again at the moment the way things are, “you simply cannot repair a car based on how much it is worth”. Just because a car is worth £750 now, it was still £15K when it was new so you are trying to fix a £750 car using the spares for a £15K car, the spares do not get cheaper as the car ages, neither does the labour rate go down and cars certainly do not get cheaper to fix as they get old, the converse is the case! The price of the throttle body was a little over the top when they could have bought a genuine VDO Siemens Pierburg unit from GSF at their trade price and sold it to you for £260 inc. VAT and still have made a good profit for themselves. The genuine Audi price is around £465 so they did not buy it there so I have a feeling they have lifted your leg a little on that one. The idle problems will be because they have not reset the learnt values in Adaptation 10 group 00 and then performed a throttle body alignment in Basic Settings 04 sub group 098. If everything else is in order, this should deal with your idle issues. Replace your coolant temperature sender and you may not be able to avoid needing a new lambda probe.