318i idle all over the place? and diff trouble

[666nobby]

Hi i have just acquired my 318i E30. The trouble is that the cars idle can be as low as 500rpm but does not stall, I think it could be the ICV but any one thats knows any differant ideas before i splash out on one would be gratefully recieved. also the rear diff is extreamly noisy, are they easily swap over. thanks

[E30BeemerLad]

don't know about the idle, check all vacum hoses for splits etc

What sort of noise is the diff making, a whine or a whooshing/metallic noise?

[Davenotouring]

Hi there.

It could be the ICV, it may be worth taking it out and cleaning it up with carb cleaner or similar before buying a new one. Clean out all the breather pipes too while you are there. Also check the rubber inlet pipe from the airflow meter to the throttle body for splits.

The diff...

Try putting a wanted ad in that section for a small case 318 diff. I'm pretty sure yours will be small case.
They are reasonably easy to swap.
You need to lift the rear of the car. Undo the driveshafts from both sides, using the hexagon type socket, undo the prop from the diff, four nuts. Undo the mouting points, there are five or six bolts onto the rear subframe I think they are 19mm (might be 17mm) and that's pretty much it.

Good luck!

[666nobby]

don't know about the idle, check all vacum hoses for splits etc

What sort of noise is the diff making, a whine or a whooshing/metallic noise?

It is a whining, there is oil in it.

[666nobby]

Hi there.

It could be the ICV, it may be worth taking it out and cleaning it up with carb cleaner or similar before buying a new one. Clean out all the breather pipes too while you are there. Also check the rubber inlet pipe from the airflow meter to the throttle body for splits.

The diff...

Try putting a wanted ad in that section for a small case 318 diff. I'm pretty sure yours will be small case.
They are reasonably easy to swap.
You need to lift the rear of the car. Undo the driveshafts from both sides, using the hexagon type socket, undo the prop from the diff, four nuts. Undo the mouting points, there are five or six bolts onto the rear subframe I think they are 19mm (might be 17mm) and that's pretty much it.

Good luck!

Thanks mate, do you know the best place to get an ICV if cleaning it does not work, is it an expensive bit.

[E30BeemerLad]

you're better off following Dav's advice and hunting down a replacement diff. If is was whooshing rather than whining then you could get away with just putting in new pinion bearings, if you could do the job yourself you're looking at less than Ԛ£50 in bits. But you can prob get a decent replacement diff for that and not have to worry about whether you put it back together properly or not.

[SwirlyE30]

Ive got a 318i and ive had problems with the idle ever since ive had it. Its so bad its unbeleiveable. Until the car warms up for the first 10 minutes it stalls all the time at junctions and in traffic its a twat.

I got a new intake hose, all the same. Got, or should have an ICV on the way, but mines all clean and seems to be ok, so im not sure it will work

[Davenotouring]

Put a wanted ad on this forum for a good one.

Failing that try www.gsfcarparts.com or www.eurocarparts.co.uk for a new replacement.

It could be something else at fault, thats the problem (ecu/wiring fault)
it's a minefield unfortunately.

[Nobby_N]

I bloody knew I joined this forum in 2005 when I had my firsy 316! I must have rejoined under a new name in 2007, must be a ban lol any admin check if this 666nobby was linked to my old email address

[Billwill]

The ICV on my 318i M40 gunges up about every six months and the idle goes for a loop.
Very easy to remove the ICV, give it a good clean and then spray with a bit of silicon spray.

If you briefly put +12 volts across the terminals it should snap open and close. A better way to test it is to leave the ICV out in the open but still electrically connected....block the hole in the inlet manifold where it came out of with a cork! Now when you run the engine you should see the ICV valve trying to make the required corrections ie. it flutters about.

Also make sure your TPS switch is adjusted properly and is electrically functional at the ECU connector and check for air leaks all around the inlet manifolds and pipes with some Carburetor Cleaner spray.

Finally if it is only a problem when cold...check the Blue sensor under the inlet manifold.