M40 owners

[smithy318i]

Does your car shake when the engine is at idle?

[dobbie82]

Yes! it never used to but the idle is getting lower (should it be about 1500 till it warms up?) mine tries to idle at 850-900 from cold sometimes, i suspect the cold start sensor/switch!

[smithy318i]

mines at 900 whatever the engine temp. it idles like a bag of shit at the mo.

[dazleeds]

idle at 1500

thats a bit high aint it??

[dobbie82]

idle at 1500

thats a bit high aint it??

sorry I don't know what it should be at warm up, was a blind stab in the dark! I am used to rovers and thats what they do!

[Jhonno]

nope - rock solid steady

[jcjdavis1]

lump free

[slinky]

Yep mine does as well, got very little history with it so don't know when timing belt was changed last so going to replace that as a precaution and see if I get a smoother idle as a result as well. If not cold start sensor switch is next!

[Gibbo]

Loads of M40s seem to struggle at idle and mine's never really improved over 15 years of mentioning it to the service engineer. But this is different to a lumpy shacky experience on cold start. This seems to be common as the miles get high and I guess only some sort of rebuild will solve it.

[bmwe30mtech]

Mine is silent at idle now, not because it still stalls!!, but because its so smooth. They should idle arround 900rpm. 1500 is way too high.

[Bob_S]

my 316i was crap on cold startup would do alsorts of wierd shit, so I bought an is which incidentally is perfect! lol

[essexboy]

mine used to idle really lumpy wen the thermostat stopped working and was running hot resulted in a cracked head on the 316, 318 i have now idles well touch wood at about 900 rpm, there can be a phew causes for a lumpy idle

[bmwe30mtech]

The M40 idle is riddled with problems, i have seen/been in so many with problems. Mine dint idle for about a year, it just cut out, so you would constantly have to hold your foot in the acellerater a bit! . I just sdjusted the bulkhead in the end. If yours is lumpy its probably idleing too slow, what does it idle at?

Edit, just seen it idles at 900 , dont know then. ICV, AFM, air leak..

[burt]

yep it shakes. When i start it from cold the revs are all over the place and it almost stalls unless you get your foot on the pedal.

[NIX]

My 318i used to shake a lot on a dodgy idle. Replaced the inlet manifold gasket and it seemed to sort things out. Now being converted to a 325i so we'll see how that goes.

[jonbuoy]

Check for hole's or split's in the air pipe going from the afm to the throttle body. This would most probably be your problem, usually split underneath

[smithy318i]

could it be a faulty engine speed sensor?

[maxfield]

My dads M3 shakes afair bit at idle. Iknow I aint an M40 but maybe something to do with 4pot. And thats on freshly built engine.

[hammoj28]

My IS shakes a bit and is lumpyish but it runs good so im not really bothered anymore.lol. Someone told me all the M3's were lumpy at idle and shake and that IS's do the same.

[Bob_S]

because we have real engine mate ;) lol

I've yet to come across an e30 with a dead level idle