Engine idling funny

[djz3r0]

Wassup, I'm a newbie and am not very mechanically inclined, but I got a few questions that I thought someone with more experience might be able to help me out with. First of all, i just bought a 96 240 a couple of months ago. Everything ran fine... for awhile. First the check engine light came on. I got it checked out and a local shop told me it was just a malfunctioning temp sensor or something, so I've been ignoring it for about a month now.
Since then, everything has gone downhill. Now my engine has started to idle at higher rpms (about 1500) every once in awhile, and it will do that every so often, but not all the time. The idling will also jump up and down, sometimes it'll cause the car to stall, at which point I always have a very hard time starting back up again. Now it has gotten so bad that I can barely drive the car anywhere without it stalling on me. I will probably take it to the dealer and have them look at it, but I'm broke as hell, and I know that I'm gonna get ripped off by them. I would REALLY appreciate any advice as to probable causes and solutions before I get screwed by the dealer. Thanks in advance.

[Jeff240sx]

Do not post questions in the FAQ section. This topic is moved to tech talk.
-Jeff

[Dousan_PG]

its most likely your O2 sensor. you car is running too rich at idle and stalling

go to your local auto store and get a new O2 sensor. dealer is much more expensive, i got my O2 sensor for like 25 bucks i think. youll also need the special tool for it (the shop should know) to make the job much easier

good luck. you can have it fixed today if you do it asap :) if that doesnt work let us know and we'll go from there.


edit: the O2 sensor is located on the manifold. it sticks out of the manifold cover, and has the wire attached to the tip of it. unplug the wire and use the O2 sensor socket to remove it. be careful you dotn want to strip it. it might be rusted in thre so prepare for the worst. you'll need a breaker bar too, (1/2 inch i think). it can be tough to get to, so take your time and be safe. also make sure engine is completely cooled down when you do this, dotn get burnt.

[djz3r0]

Sorry about the FAQ thing. That sounds good, I'll try it today if I can, and I'll let ya know if it works. -Thanks.

[Dousan_PG]

werd. just make sure you get the socket, makes the job easy. a normal socket cannot go on the plug because of the wire, this one is like a socket, but the side is cutout to allow the wire not to be crimped!


some auto stores might rent it??? might ask about it.

[Dousan_PG]

o2 sensor socket:

http://www.bmwe34.net/E34main/Maintenance/O2%20sensor_data/O2%20socket.gif

[djz3r0]

I forgot to ask, I have 2 on my car don' t I, one on the headers and one on the cat. converter? Should I go ahead and change both? I was also reading some of the earlier threads and I was wondering the problem might be with my engine running too rich? Cuz I've been having a strange smell coming outta my car after I changed the spark plugs and my tranny fluid. Could it also be the temp sensor also, or should I go ahead and get it all changed out. I really want my car runnin normal again but I don't wanna spend $$ on parts that might not be malfunctioning. Anyway I'm headed to the auto store right now to see if I can find an O2 sensor and that socket. -Thanks again.

[Dousan_PG]

dont know about 96
o2 sensor might go under exhaust temp sensor at the autoshop.

[russian]

i usially settle problems like this by beathing the **** out the car with a baseball bat and breaking empty beer bottles on it :)

its probably what someone already said your 02 sensor. your car has diagnostics on it, take it to Autozone, they have free engine light check will take 2 min, it will tell you exactly whats wrong. actually you might have ecm malfunction, it can be anything, get it checked again.

[Bbandit]

it is better to check your filter and throttle body first before getting yourself a new 02 sensor
i had the same idle problem
what i did was..
i took out the whole intake..
check my intake filter, clean it (or if its still stock and it looks dirty, replace it)
and then
get yourself a throttle body cleaner and a used toothbrush
clean the inside part of the throttle body by spraying the throttle body cleaner.. and then brushing it thoroughly...
start up the car..
if it still idle like sh*t.. get yourself a new 02 sensor

[Anubis]

im too lazy to read all the posts, but if your having idle probs, check ALL vaccum lines. One of mine was cut and it caused the s14 to stall at idle. I replaced the hose and now its great.

[djz3r0]

Hey, I got the car checked out, and the guy told me it was the temp sensor that was causing the idling problem. I replaced it and reset the engine. Everything seems fine for now but I only got to drive it to and from work. I still got a strange smell from my car though, smells kinda like trans fluid. Anyway, thanks alot for all the suggestions. Just hope the engine light doesn't come back on again. -Thanks again everyone

[Dousan_PG]

rad!

glad to hear its all good.

[AceInHole]

Originally posted by djz3r0
Hey, I got the car checked out, and the guy told me it was the temp sensor that was causing the idling problem. I replaced it and reset the engine. Everything seems fine for now but I only got to drive it to and from work. I still got a strange smell from my car though, smells kinda like trans fluid. Anyway, thanks alot for all the suggestions. Just hope the engine light doesn't come back on again. -Thanks again everyone

temp sensor is only used for onboard diagnostics.... the car should run fine without it, at least the 95 FSM says anyways.

Maybe the ECU just needed a reset overall?

[syco3d]

First off, how do you reset the ECU..and second, if you're not doing it because it's needed, could it possibly cause harm in doing so? Ie. can reseting the ECU just be considered part of general maitinance.