Rough Idle?
 

I've read many articles on the idle surge and they mostly only deal with the ICV. Here's what I did:

1)Replace or clean ECV, mine was crumbling, and air hose for it. The hose is actually 2 hoses, only available together. Here you can see the upper hose which connects to the ECV and Valve Cover.
http://img73.imageshack.us/img73/9272/p10000891vb.jpg
The lower hose connected to the bottom of teh ECV runs coolant so alittle will spill out when you pull it off (do this with a cold engine!) but its not enough to worry about--like maybe 2 oz. Now here's the fun part, the other end of the coolant hose connects to the back of the engine block, I removed the battery & battery tray to get better access.http://img96.imageshack.us/img96/6924/hose0xh.jpg
The ECV can be removed from its underside by removing two 5mm allen bolts.
http://img476.imageshack.us/img476/151/ecv5jq.jpg

2)Remove and clean or replace your ICV. There is a small green paper gasket for the ICV and if you're really careful, you don't have to replace it.http://img99.imageshack.us/img99/9304/p10000906qp.jpg With this I did the usual, spray down with carb cleaner (I prefer brake cleaner) working the little metal valve/door, q-tip etc. and after it dries a quick spray of WD-40 or the like.

3)Probably not necessary, but I did it anyway, I pulled the Smog Pump check valve and cleaned it and replaced it's air hose too.http://img66.imageshack.us/img66/4494/p10000876yl.jpg

4) I also pulled all of the Intake hoses and checked for cracks/blockages.
http://img236.imageshack.us/img236/307/p10000935sv.jpg

Final thoughts.....re-attaching the ECV is a pain. You might want to put a swear jar down in your garage, by the time you get it back on you'll have earned enough $ to get that DASC you've been wanting!

Wowee! that definatly helped! my hose was totally corroded. When i was replacing my microfilters i guess i pushed kinda hard against the hose and popped a hole in it. So i was getting rough idling and then squished the hose together and it FELL APART. $2.50 later and a trip to lordco to get a new hose and i dont have any idling problems.

woohoo!

still going to clean the ECV though, its probably pretty ugly. Same with the idle regulating valve

Should ECV be PCV (Positive Crankcase Ventilation)? That is the black disk on the intake manifold flange with the hose going to the top of the valve cover.

ECV/PCV same thing.

Ah yes! Technological advances----> I just bought some Sea-Foam in an aerosol can, no more WD-40 etc. for the Idle Reg. Valve, now I spray in the "real deal".

i just did this minus the smogg and as far as i no it work but still want to see at a cold start and if that doesnt work idk whats up then thanks

how do you get bottom hose off? bolts? Clamp?

Just replaced my PCV valve and hose...what a pain for only 2 bolts!

Hi
 

Fourth pic down is that you idle control vaule and if it is what is the thing your cleaning lol ::P

Hello,

I know this thread is a bit old, but I have been looking for that hose that connects to the PCV valve, and I cannot find it. Can someone give me the part # or the link to that hose?

Hi there you are right on the money in terms of replacing the two hoses and the PVC valve!

A former BMW mechanic advise me to just cut the hose off do try to remove it nicely its not worth it cut and replace.

M42 Rough Idle Last Resort Fix
 

Hi guys this may not be specific to you but if you have tried everything and have not gotten anywhere with the rough idle, poor performance, rich fuel check my video i discovered something today and uploaded a video on what i found that was causing my really rough idle, running rich, sounding like misfiring on idle etc,

I came across this out of frustration as i ordered in some parts from NZ one of them being the AFM out of an M44 but to no avail it was not a PNP to my M42 318ti. So out of frustration i took apart the M42 Air Meter and with just a little adjustment to the loaded spring for the barn door on the AFM this gave my car the new smooth idle feel, no more misfire like sounds on idle or even driving, and car runs much better on the road and iv seen a drastic change in my KM/L

here is the link to my youtube video. Hope this helps.

http://youtu.be/MTnB5X4lURk

Cool information! Thanks!


Dave