M20 wont rev past 4k rpm

[jmc330i]

Hi from the UK.

Ive just gone to view and am hoping to buy, a 1989 manual 325ise - 178000miles but with a lot of history. Its in pretty good condition for a 16-17 year old and it drives really well, nice and smooth, but it does have a problem.

It will rev from idle with no problems at all and is smooth until 6k rpm, but when driving and its under load it wont rev past 4k rpm and it stops with a jolt (only got to 4k rpm in 2nd and 3rd) - its almost like the rev limiter is cutting in. It will rev fine when coasting along in gear with the clutch in.

Ive heard it could be AFM, dodgy crank speed sensor or even the speed sensor on the diff, but Im not sure where to start.

The car was serviced just over a year ago, but has only covered 8k miles since.

I know there are a few differences between our Euro 325i and the US version, but can anyone please help shed some light on what the problem could be.

Cheers

[AdamF 88iS]

Could be the AFM, had a similar problem on my M3 before.

[chuckybob]

afm seems to be the most common cause of this

[jmc330i]

Thanks for the replies guys, but unfortunately I didnt buy the 325ise.

The trader selling it turned out to be a bit of a d*ckhead. When he started saying all 325i cut at 4k rpm when driven hard and that the clutch was at fault and it needed a new one, he talked himself out of selling a car, especially when he wouldnt drop the price at all, even though according to him it needed a new clutch.

I know for a fact the clutch wasnt slipping - during the test drive I found out the fun way it didnt have an LSD!!
And I also know that my 325i Sport doesnt cut at 4k rpm when driven hard.

Still, his loss and I can look out for a better 325i.

Cheers