Hello guys,
Have had bimmers for quite some time but new to e24s and the M30.
I've searched the forum for likely answers but can't be sure so I would like to ask:
My M30 has a constant oscillating idle per the video below. ICV seems to be fine and there doesn't seem to be any leaks from the vacuum hoses, according to my mechanic. I'm thinking it's either AFM or injectors. Does anything else come to mind or has anyone had similar issues?
https://m.youtube.com/watch?v=8Ewi0HuwmlY
Another thing is cold starting. The engine will crank and turn on but can't maintain idle. It'll stall if I don't help with the gas pedal: both on cranking and when the engine is on, for the first 40 seconds, until it is warm enough to maintain idle. I've read about the cold start valve and temperature sensor being the culprit but it seems like they only work during key turn, right?
https://m.youtube.com/watch?v=T0ATygHeC2g
Appreciate any advice.
thanks!
Have you checked your Aux Air Slide Valve [part #13631284414]? Late '82-'84 Euros have this part, some discussion towards the end of this old thread here: https://www.bimmerforums.com/forum/s...ir+slide+valve
More visuals in this thread (the '80-'81 E12 part is the same as in our cars): http://www.firstfives.org/faq/aux_ai...air_valve.html
This fixed my issue when I was having similar symptoms. I'm a little confused when you say ICV seems to be fine as this generation of Euro doesn't technically have one (they arrived in '85).
Hi Lapis,
Thanks for your reply. I'll look into buiyng the air slide valve, if I can find it within the online stores. Given it's for a Euro motor, none of the traditional stores in the US carry it (Pelican, FCP, Turner, etc.)
When I mention "idle control valve", I'm referring to part #13411286065.
While I'm at it, might as well look into a new cold start valve and temperature switch, I guess.
THanks again,
Best,
Pedro
The cold start is a huge whore to change JFYI. Maximillian should be able to order the slide valve.
alpinweiß on anthrazit buffalo 1984 745i, 2014 Fiesta ST, 1984 635csi 1986 635csi 1987 L6 1999 M coupe 2002 M3 1995 325i 1976 2002, 2001 996 TT 1994 850 T5 wagon 1998 GTi VR6 1983 scirocco
Hi Freshbread,
Thanks for the info. Sorry but who is Maximillian? a member of the group here?
Also, if you or any of the viewers have any comments on the oscillating idle issue, per my original post, I'm all ears!!!
Best,
Pedro
Maximillian is a website that you can puchase from. They can get a lot of euro parts. I've ordered from them before.
Classic intake leak symptoms.
By that age, rubber intake boots and all vacuum hoses have deteriorated, if they've never been replaced.
Remove and carefully inspect all rubber boots and miscellaneous engine vacuum hoses,
Replace all with any sign of cracks.
Also, remove and inspect all tune-up parts:
Sparkplugs & gap, along with wires
Distributor cap, especially inside contacts condition
Got it.
Thanks dmac156 and Mikyzzz4!
Report back with your results.
Been a while but better late than never, also for future reference for those with similar problems. Air slide valve was the culprit. Thanks again for all the help given.
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