BMW Werkz banner

Rough idle.... (help, please!

26K views 16 replies 9 participants last post by  greenlightracer 
#1 ·
My Engine idle pretty roughly, especially when started from cold but it continues through out the day. It also makes a clicking noise, which I beleive is just the valves that need to be adjusted. Am I correct? Any idea on the idle? its like a chug almost. The BMW dealer wants 120 to do the valves, but 400 to fix the idle along with 700 to do the timing belt.... grrr :banghead . I can barely afford this thing.
 
#3 ·
The timing belt is a weekend job and can be done yourself for under $100. I'd go ahead and pay for the valves, you can really screw yourself over trying to do it yourself, and $120 isn't too awful.

If he wants $400 to 'fix the idle' I'd at least have him explain the problem to you so you could debate tackling it yourself. You may just need a new O2 sensor or ICV.
 
#5 ·
Mine is a '87 325is, idle is a bit rough, and it does not changes when the engine warms up. But the engine revs up sweeeeeet, is as if it is all it realy wants is to run fas all the way, but the idle beats me.
I purchased it less than two months ago from a lady whos son had just replaced the radiator and hoses, the ac compresor and hoses, all brake calipers pads nad hoses, 4 new tires and he had some work done to the head. They did spend over $3000 on it and I paythem $1600 for it, but I cant get a hold on the kid to find out what exactly he did to the engine. I just now tha it has a lot of power; I can make it chip the tires when gearing to 3rd at almost 100 kph. :driving
 
#7 ·
yeah, spark plugs could cause that, i know the last time i changed my plugs they were gapped wrong (usually doesnt happen, they are pretty good about being gapped out of the box) and it caused my idle to suck and it ran like crap until i gapped them correctly.
 
#9 ·
If the motor actually sounds like it's going to die, not just that it dips really low, then try slipping the clutch a bit more and revving a little higher when you take off. That'll keep it from stalling - you may just have a bad throttle cable or something, I think that's what's causing some troubles with my car.

I really don't know if a lot of other BMWs do this, but most of the people I've talked to around here with Etas have slightly bouncy idles. I think it may just be the nature of the interference engine. Unless it's shooting up or down 500rpm, I don't think it's anything to worry about. If it's getting on your nerves, and you haven't done so already, try replacing the ICV and/or spark plugs, wires, injectors etc. Even if that's not causing the problem, it won't hurt anything.

It's also a twenty-four-year-old car.
That right there can explain a lot.
 
#10 ·
um, mine is only 14, with 90 k on it :blink: I dont think age is a problem here. Let me correct myself on this: the car more or less idles at about 700 RPM... it doesnt move. the engine actually vibrates. it "chugs" as does the entire exhast system. Its an automatic and I have an 325i, so, its not the ETA engine u were talking about.
 
#14 ·
cheack you Throtle position sensor (TPS).
If you say your idle goes to 3000 rpm, it could be the problem.
To test it real quick:

Stop the engine,
Open the throle by hand about 20 degre.
close it realy slowly. I should say let it close by itself slowly.
Listen for a "click" when it is almost closed.
You should hear it. If not, try to force it closed by hand .

This click tells your computer to go in "idle control mode"

If you dont hear it or have to force it, your TPS need an ajustment/replacment.
could be that your throtle cable is ajusted to short to.

try it, it only takes a minute.
 
#16 ·
I had this same issue on my 84 325E. Bouncy idle - up to around 2k then back down to around 700 (no stalling). I cleaned the IC which seemd to be working properly anyway. No effect. Finally, I dd some reading on the web and found a workaround that seems to hav fixed my idle problem for good. Take a penny and drill a 1/4 in hole in it. It doesn't have to be exactly on center or anything, just a hole. Put the penny in the vacuum hose on the intake side of the ICV and put the hose back on. Start the car. You may have to adjust the screw on the top of the ICV to get the idle where you want it, but mine stays solid at right around 750 rpm. I'm guessling on the actual RPM here, as i used the tach in the car to set it. Seems to work great for me.

If the engine is actually stalling, it almost has to be a vacuum leak or fuel pressure. I would guess that it's not fuel pressure if the car runs fine in all other respects.

Good luck!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top