cold start help!!!!

Thu Jul 07, 2011 10:10 pm

Hi all,Im new to the forum and had a wanted ad for an e30 on here after always having vw's gti/vr6 g60's etc and just being basically bored of them.

Anyway i was looking for a 2dr 320/325 but some how i have ended up with an immaculate low mileage 2dr 316i lol.Please dont slate me as i just had to as it was just so original and even has a period pioneer snatch stereo in(will be coming out to be replaced with more modern ice)

Anyway enough rambling

My problem is when i start it from cold it will not idle,Yet if i sit with some revs on for a period of time say 30 secs it will idle.My thoughts are auto choke not working or possible sensor,If it was a vw i would have fixed it allready but i have no knowledge of bmws.

yours or any help would be great as its the only niggle i have with it.

Fri Jul 08, 2011 10:10 am

mine did that the first couple of times i started it, however mine had been stood for 5 years. Service, fresh fuel and an engine bay and component clean up and started and idled fine.

Check plug, leads, coil, dizzy and clean them up (quick and easy to do), then try starting again. If you have the same issue, then check in air intake pipe for splits, then if all is ok you need to check the Blue Temp Sensor (route of almost all evil).

Fri Jul 08, 2011 10:50 am

i have been having a look and all is ok but where would i find the blue temp sensor?? i cant se any anywhere

Fri Jul 08, 2011 10:57 am

meltonbmw wrote:i have been having a look and all is ok but where would i find the blue temp sensor?? i cant se any anywhere

This must be an M40 engine,then!
Blue sensor is cunningly hidden under the inlet manifold,on the side of the head.

Test as I expect you would for a VW,should be a noticable difference when measured for resistance between hot/cold.They usually fail in the cold position,though,so this could not be your real problem,I would be searching for air leaks,as un-metered air is the usual cause of poor running.

Fri Jul 08, 2011 11:08 am

When was the air filter last changed?

Fri Jul 08, 2011 11:20 am

Found the problem fellas cheers,The blue sensor was broken at the end so am off to get a new one now.Dis find that the heater matrix was cunningly bypassed tho.Didnt notice when i bought it.Not very at this moment in time!!!!

Fri Jul 08, 2011 11:28 am

how difficult is the matrix too change?? it looks straight forward and im ok with a spanner but am unsure if there are anythings i should look out for before i tackle it lol

Fri Jul 08, 2011 11:37 am

meltonbmw wrote:how difficult is the matrix too change?? it looks straight forward and im ok with a spanner but am unsure if there are anythings i should look out for before i tackle it lol

I have not done one myself so cannot comment on exactly how to do this,but my impression is that the matrix slides out into the l/h footwell,you will need to clear out things like the glovebox and it's liner.

There's a pair of O rings on the matrix end of the pipes that cost pennies,make sure you get a couple!

Heater complete is a dash out job(and it's held by 4 bolts on the engine side of the bulkhead)

Fri Jul 08, 2011 11:55 am

heater matrix as a rule are not difficult regardless of what car they are in. Good news its only the blue temp sensor that needs replacing, they are pretty cheap and normally availble in your local ECP or GSF, failing that its a trip to the stealers, or just ask cotswold on here.

Fri Jul 08, 2011 9:23 pm

Well thanks for the info on the matrix,I have replaced the blue sensor but still the same unfortunatley.Does the 316i have any cold start valves on them or anything else??I have check for air leaks etc but all seems fine. am i barking up the wrong tree with the cold start valve or isv

cheers