318ci iratic idle

[Xpistos]

Hi all

First off let me introduce myself, names Chris and I've had a few bimmers over the years. Just got a used 318i n42 with 85k on the clock.

Cars been looked after got full service history loads of invoices for all the basic service level stuff (filters, fluid and plugs) however it's got a very iratic idle (splutters and makes the car shake). I did an odb fault check and it came up with both 2783 (maf) and 27c3 (oil sensor). Now I removed the maf cleaned with electrical contact cleaner and re fitted and it seemed to help for about 30 seconds then the car was back to spluttering. After clearing the codes the maf one is back.

I've looked alot into this issue and there are a number of reasons behind it but I'm struggling to narrow it down, currently it's only an idle issue and it gets worse the more the car warms up. It dosent effect driving in anyway and just putting the air con on to raise the idle slightly actually solves the issue.

What do you guys think? Any suggestions on where I should start looking?

Many thanks in advance guys, trying to get this car on the road for my mom she's just upgraded from a corsa!

[TonyAngel]

maybe a vacuum leak. check the intake plumbing. obd scans on bmw are next to useless. you need a scan with a bmw scanner. it may tell you something more.

[Xpistos]

Just for anyone else reading this down the line the issue turned out to be a vacuum leak, a big one someone hadn't connected the vacuum hose that runs fron the top rear of the rocker cover to the oil seporator, plugged it back in and the cars perfect again

[TonyAngel]

Good deal and kudos to you for helping your mom out. If you're gonna be doctoring this car for her, you want to get into the diagnostic and software section and set yourself up with a cable and software for a laptop. Could save you a lot of headaches in the future.

[TonyAngel]

Also, I don't know if the 318 is prone to the same cooling system issues as the other E46s but you may want to look into it. When I bought my E46 I had to redo the whole cooling system. Lots of plastic that gets brittle with age. Some had problems with water pump impellers letting go too.