need some help

Mon Apr 15, 2013 4:59 pm

I have a 1990 e30 316i when Im at high revs the car won't go over 4500 rpm and not sure why feels like its hitting a restriction but there isn't one anyone have any idea much appreciated[/img][/quote][/url]

Mon Apr 15, 2013 5:01 pm

can you depress the pedal to the floor?

Mon Apr 15, 2013 5:04 pm

What you mean depress lol

Mon Apr 15, 2013 5:04 pm

Typical sign of a badly worn camshaft.

Good part is that it can be changed without removing the cylinder head.
Bad part is that the rockers and lifters are probably buggered as well,and although single parts are available,by the time you have bought eight lifters,eight rockers and a cam,you will have spent a lot more than the cost of a good s/h engine.

To check,remove the top cover and look for ridges on the cam shaft lobes.

Cause of the wear is usually oil starvation,from a blocked spray bar.

Welcome to the zone,BTW.

Mon Apr 15, 2013 5:05 pm

Sounds like you're suffering from the typical M40 knackered cam syndrome.

Mon Apr 15, 2013 5:06 pm

Cheers buddy and aaaa lol thought there might be a big job somewhere lol could it be caused from a breaking down spark eg coil dizzy leads

Mon Apr 15, 2013 5:09 pm

Lol is this a regular problem then

Mon Apr 15, 2013 5:24 pm

noodles-e30 wrote:Lol is this a regular problem then

Yep, mostly caused by neglect leading to a blocked oil spray bar as Malcolm says. Most M40 turds are notoriously tappy.

Mon Apr 15, 2013 5:33 pm

Shame coz Its clean but guess the lads who had it before just thought ooo BMW I'm gonna ragg it lol

Tue Apr 16, 2013 8:54 am

darkchild wrote:Most M40 turds are notoriously tappy.

Pretty sure I was lucky and that my old one was the exception to the rule!

Tue Apr 16, 2013 9:21 am

Cheapest and easiest solution is to swap the cylinder head, or even the whole engine for a good one.
An ignition fault can give symptoms like this as well, as you suggest, but in that case, the misfire tends to happen under load, rather than at a specific engine speed. If it feels exactly like it's hitting a rev. limiter, then it's the cam.
Take the rocker cover off and check the tips of the cam lobes. There's an 'unused' area at each side of each lobe which doesn't wear. Any step between this and the polished bit, and the cam is toast.
Note that this "tech help." section is for BMWs other than E30s. I've moved it to the correct forum for you, where there is much more activity.