Ahh, the good old CEL - BMW Forum

4evrwyntr · 02-24-2006, 09:31 AM

Check engine light came on today, while car was running warm.
It flicked on either at the beginning or just before a left hand turn, downshifting from 3rd to 2nd.
No noticeable difference in power/revving, idle remained the same, engine felt normal.
No abnormal noises.
No abnormal smells.

The car has 90100 miles on it; new coolant radiator, new coolant radiator expansion tank w/ new thermostat, new water pump (bearings blew), new engine fan. It is missing some heat shields underneath the rear seats for the exhaust (rattling, so they were removed). Only other differences are non-engine light issues (K&N filter, slotted rotors, aftermarket pads).

I'm thinking I need to just change out the O2 sensors... I don't have a code-reader so I really have no clue. Any ideas?

kyle_baker · 02-24-2006, 09:58 AM

just check to make sure there is enough oil in it and that it's not running low. also, you might just want to check the level of coolant to make sure its not leaking out anywhere even tho its all new.

drz · 02-24-2006, 10:00 AM

Have the code read at an autoparts store. They do it for free. Once you know the code, come back and tell us what it was. Then we can help you determine a course of action. There are many things that can throw the CEL, including a lose gas cap (you a scientist, so I am guessing this one didn't slip by you). One cannot simply assume it is an O2 sensor, but at the current mileage, it just might be.

Furious · 02-24-2006, 10:10 AM

another note the K&N air filter is part of, one of the most important parts of the engine :P

drz · 02-24-2006, 02:19 PM

Very important, indeed.

4evrwyntr · 02-24-2006, 04:04 PM

Yes, yes it is. But a failure in the filter itself... :P

Anyway, yes, checked the filter, oil is fine, coolant is fine.

Actually, went to take it to an autoparts store (autozone) to get the code read and was going to update... except the light disappeared. Huh. I'm going to give it a better once over on Sunday, when I might have time. Time. Who has time.

Furious · 02-24-2006, 05:10 PM

Quote:

Originally Posted by 4evrwyntr

Yes, yes it is. But a failure in the filter itself... :P

Anyway, yes, checked the filter, oil is fine, coolant is fine.

Actually, went to take it to an autoparts store (autozone) to get the code read and was going to update... except the light disappeared. Huh. I'm going to give it a better once over on Sunday, when I might have time. Time. Who has time.

lol true, however if a filter is too clogged it can cause problems, and if your running forced induction, sometimes the filter will implode... haha my friends filter sucked right once on his turbo civic..

anyways i wont go too off topic.

back on topic. im guessing its the O2 sensor, i had the same crap happen to me when i had my first CEL, and it hasnt come back on in 3 years.

BImmerN2B · 02-24-2006, 06:19 PM

You could also buy the bmw code reader sold in bmw online parts stores or also can get one from a regular auto parts store like Pep boys or the like. The Bmw specific code reader is great cause you can also clear the oil and service lights. Or be cheap like me and steal the regular one from your ex-girlfriend and use it.

4evrwyntr · 02-24-2006, 11:05 PM

I would love to get a code reader and do the work myself. Except I do not have a garage. No garage -1 ftl.

Delmarco · 02-25-2006, 08:42 AM

is your gas cap on?

also you can read the codes yourself without any equipment.

1.stick key in ignition.

2. turn key to 1 spot.

3. firmly and fully depress gas pedal 5 times quickly

4. the CEL will begin a series or "morse-code" blinks. you will look for a string of 4 numbers or flashes followed by a long pause and then another string of four numbers. For eg. 1-2-3-4---------1-2-3-4---------4-3-2-1---------4-3-2-1--------1-1-1-4-----------1-1-1-4 . These four number (s) will provide your problem code (s). If you have more than one problem then look for a series of different numbers followed by their respective pauses.

Dude,
Your car has been giving you lots of problems. I'm feeling upgrade to
problem-free 1995 318i model.

4evrwyntr · 02-25-2006, 10:35 AM

Hmm.... that's a neat trick. I'll try that if the light comes back on.

And I'm pretty sure my car is giving me normal problems. Let's see... water pump and radiator as well as some fog light problems... Aside from the rust (which I don't know how that happened)... for an 8 year old m3... that I just put 30000 miles on in the last year...

Yeah, sounds about right IMO.

No, you can't have my car.