4.4 missing at cold startup
 

Hello, '01 4.4 with 99K slight miss at startup. It is somewhat sporadic and the engine may start and run fine for 2 seconds and then break into the miss for amout 2 to 5 seconds then be fine. All runs great otherwise once warm. It does this more at cold startup and also will do it less so when restarting when warm. It does not light the check engine light, but perhaps it will register miss fire? Any leads greatly appreciated.

how many miles do you have..? have you replaced spark plugs yet?

first thing is to read the codes, must be something stored. if its indeed a misfire you can start the diagnosis which cylinder is missing.

ok are you using the correct engine oil? if no codes stored than i cant really say whats what. maybe injectors are bad / fuel pump? maybe something is wrong with oxygen intake although cant really explain how these wouldnt be accounted for once car is warmed up. how do you feel that its missing? does the engine start to choke or does it shake? maybe someone else could take over and help... deff report back

Does the 4.4 have VVT? as there have been posts on the site about the units not working correctly on start up until they fill with oil. At least I think that was the conclusion. Try doing a search on 'intermediate levers'

IanP: Yes, I am aware of the startup rattling that can come prior to oil pump-up. This isn't doing that.
TEMA: don't know how to describe it, but there is a distinct quality to a V8 missing on one cylinder. This is displaying it. If the miss would continue, I would be able to identify the cylinder within a few minutes.

I'm not sure if the enhanced diagnostics at the dealer would give more missfire info, but the lack of any errors is leading me to think of temporary missfiring of the injector on a mechanical level. My theory being; if there was an electrical/coil problem, I would think that it would register, but I may be wrong.

here is what i found. 97 540i misfiring problems!! - Bimmerforums - The Ultimate BMW Forum

but you should also try and disconnect ignition coils one by one. i mean disconnect one if engine behaves different put it back and disconnect the next to identify which coil is bad if any are.

Thank you, now my only problem is that this is not happening at all. perhaps once and if it repeats, I can narrow down the problem