Acceleration dies at 4,000 RPM

[marks]

Can anyone please tell me what my problem is likely to be please....

Within the last month or so I have noticed that the car is nowhere near as quick as it was (99 Avant). The most noticeable lack of pace is when the car hits 4,000RPM. Up to this mark it pulls ok, however when I hit this point ( no matter what gear I am in) the car seems to be straining against something and it really doesn't want to accelerate, gradually it does but with no conviction what so ever.

Thanks in advance

Mark

[mikeyquattro]

Get it vagcom'd asap

[Nige_RS4]

Usually MAF, but could be any number of things - as above - get VAG-COM on it - look for any error codes, then check the MAF output at WOT in 3rd & post results back on here.

[marks]

Thanks men.

I don't know if the MAF has ever been replaced. I have had the car 18 months and it is something I have been meaning to do. Could a mechanical <beep> (me) do this myself?

[s4yogi]

Yes very easy to change its between the airbox and acordian hose, replaced mine just after i got it, car wouldnt go over 70mph missing and spluttering

[marks]

Is this a pricey exercise?

[Nige_RS4]

Around £80-90 fro an exchange unit from a stealer, maybe cheaper if you ask Woody on this forum for a quote.

[marks]

Any idea what a stealer would cost to supply and fit; if it is an easy job, or would this be plain stupid....

[CliveH]

Mark - when I first acquired my S4, the MAF was knackered and in my ignorance I had it replaced and fitted by a stealer for around £250.

Since the education of this forum, I wouldn't hesitate in fitting a replacement myself - it really is very simple - and this is coming from someone who IS mechanically challenged (there's plenty on here who will vouch for that!)

If you're really not confident in doing it yourself, take it to a good independent specialist - that way, it will not only be cheaper, but it will be done properly (yes, I know it's an easy job, but you'd be surprised...), and they'll carry out a full health check for you too (for about £50).

[marks]

Cheers Clive.

I may well give the people who did the idler pulley, in the new year another shout, as they seemed competent and reasonably priced

I am not sure if they would give it a full health check though. Being near Norwich there is not an abundance of suitable venues, I am to and fro London at present so I can't zoom somewhere like MRC sadly.

[tartan_rob]

The MAF is an easy change. Order one from VAG-Parts and you'll work it out. It is only 2 jubilee clips on those cars I think.

I had something similiar a long time ago, turned out to be the mechanical timing out. MRC Diagnosed and mapped around it for a short time before we could agree a time for them to do it properly. I do hope it is not that...

[marks]

Rob, do I dare ask what that entailed ?

Mark

[tartan_rob]

Mark - Effectively replacing the timing belt. Front of car off job.

If the car was fine before the idler pulley was changed then when the idler pulley was done, was it possible they for some unknown reason, removed the timing belt or slipped it off a camshaft etc? Can't think why they would do this as the idler pulley replacement is quite an easy job with the front of the car still ON.

[Nige_RS4]

Rob, I think you're scaring the guy now!

It is more than likely to be the MAF or something simple like DV's than a slipped cam belt, bearing in mind the problem wasn't there before.

Get it vag-com'd and check the MAF output.

[tartan_rob]

Agreed Nige. Go for the simple things first, post some logs and the forum members will be able to help as best they can.

If it is mechancial though, best to isolate when it happened, aportion blame if it happened when idler pulley done and more importantly, get it fixed.