2002 M3

[central3 31]

Only now getting used to driving this vehicle – nowhere near as refined as my old 330i but these are obviously very different vehicles. The M3 has an intermittent surging thing going on - I would like to know if this is normal or not. Typically under light throttle in intermediate gears (2nd, 3rd, and 4th) the car sometimes surges – not quite a miss fire, more un-even acceleration. Seems to be there hot or cold but sometimes not there at all and sometimes quite intrusive. I would appreciate any comments from other E46 M3 owners etc

[Greg111 13]

Not an owner but i do work on them, i have experianced this problem on these M3s before, only when cold though, once warm the issue goes away, best to get it checked on the diag, see if any faults are present, was gonna say fuel filter could be blocked but you say sometimes the issue isn't there at all?

[central3 31]

Yeah but it's there more often than not but only at part throttle. At full throttle there is no surging at all - very smooth/aggresive. Agree re the diagnostics check but keen to hear form other owners as to whether it is normalish - not an issue on you E36 M3 I take it?

[Neal 512]

In my 2002 I only get surging in 1st & 2nd which its cold whilst travelling up the short hill where I live. Very smooth when warmed up. Only issue I have is running 96 oct after 98 oct where I get light pinking.

Edited November 20, 2011 by Neal

[Greg111 13]

Nah, never experianced on E36s. And yes there on part throttle but not at full throttle, the couple i had seemed to be an over fuelling fault. When warm they tend to lean out a bit.

[central3 31]

Cheers Neal - I too have noticed the slight pinking - wasn't until I drove the car with the windows down and loaded up the engine at low rpm - not constant and I (believe I) can hear the electronics managing this - I wonder if the surging is emphasied with a MT versus SMG

Edited November 20, 2011 by central3

[Neal 512]

A gentleman from Porirua European seeing my M3 told me he'd recently supercharged an M3 and pointed out that a comon issue for the e46 m3 is that the airflow meter/sensor is know for causing surging on E46 M3 and the E46 330. He was taking about some way of bypassing it as per CSL setup which improves drivablitiy.

I might have miss-understood as I'm an IT person rather than automotive expert but here could be your answer.

[Greg111 13]

A gentleman from Porirua European seeing my M3 told me he'd recently supercharged an M3 and pointed out that a comon issue for the e46 m3 is that the airflow meter/sensor is know for causing surging on E46 M3 and the E46 330. He was taking about some way of bypassing it as per CSL setup which improves drivablitiy.

I might have miss-understood as I'm an IT person rather than automotive expert but here could be your answer.

Never heard of this? The CSL has a map sensor, any car can be converted to map sensor if you could be bothered, not easy.