Check engine light

[e30evolution]

ok... so here is the deal the other day i went to check my oil, and there was no oil cap.... it had come off for some reason. so i got a new one.... and now if my car sits idleing the check engine light comes on.... when i open the throttle plate the light goes out, which leads me to believe it is a vacuum problem, like there is too much vacuum being created...
the car runs fine, but if the check engine light comes on that means something is no working properly.

please let me know what you think

[Super Eta]

Finally im not the only one except i had the oil cap on all the time.

I just ignore it since the car runs just fine and i have bigger things to worry about.

[KevinM]

Turn the key to the ON position but don't start the car. After three seconds the check engine light will flash in intervals of one second.
1 flash: air flow sensor
2: o2 sensor
3: coolant temp sensor
4: throttle switch

From the sounds of it I would guess its 1 or 4.

[Erick]

Turn the key to the ON position but don't start the car. After three seconds the check engine light will flash in intervals of one second.
1 flash: air flow sensor
2: o2 sensor
3: coolant temp sensor
4: throttle switch

From the sounds of it I would guess its 1 or 4.

Interesting, I have a very similar problem with the check engine light, but whenever I flip the key ( once ) I never saw those flashes..... I'm going to try that again....

I know my coolant sensor is messed up....

[Super Eta]

Mine doesnt flash. :?

[e30evolution]

the air flow sensor is in between the MAF and the throttle body right? i think that is what the problem is... i got a new oil cap... the check engine light didnt come on until after i put the oil cap on... i think inside the valve cover is building up too much pressure and that is why the oil cap came off, and why the check engine light only started to come on when i put the new oil cap on.... i will check and see tho

[Erick]

I flipped my key and the check engine didnt flash at all.

By the way.... the airflow sensor is what you are calling the MAF. Remember, e30s dont have MAFs ( unless you put one there and I'm not aware )....

[AdamF 88iS]

Only Motronic 1.1 cars flash like that. This means 87 and some early 88 325i's.

If you have an 89 or up then you have to turn the key to the on position, FULLY floor and release the gas pedal 5 times in a smoothe rapid pace. After you do this the CE light will flash a 4 digit code to you.

If you have an '86 or older car, or an M3, then you dont have a check engine light at all.

[KevinM]

Sorry forgot to mention that. I just assumed you had an 'i' from your sig I guess. You shouldn't need to touch the gas pedal at all though.

[AdamF 88iS]

Sorry forgot to mention that. I just assumed you had an 'i' from your sig I guess. You shouldn't need to touch the gas pedal at all though.

They will both have to touch the gas pedal since they both have late 'i' cars. 5 times, all the way to the floor and back. This is for Motronic 1.3 and up.

Only 1987 'i' cars, 1988 super etas and a handful of very early 1988 'i' cars do the flash without hitting the gas. This is Motronic 1.1 style.

Only Ryan (Super Eta) doesnt get in on this. He has Motronic 1.0 since his car is 1986.

[KevinM]

Nice, that clears that up. I always figure my superE is basically like the i's ecu-wise. Oops

[OOMPH!]

e30evolution, my car has the same problem.......I went down to my buddies shop and hooked my car up to the computer and it read that the O2 Sensor was bad. I haven't replaced it yet, but I will soon. I'll Let you know........

[Brian 89 325i]

I did that thing to my car and it:

Flashed once then waited a while
Flashed again and waited a while
THEN i flashed 4 times. Does that mean i have a bad throttle switch?

Brian

Edit: Also on cold startup it seems like im missing or somthing. It runs perfect after like 40 seconds or idling but just real rough on cold startup.

[e30evolution]

when i turn the key to the on position and pres the gas pedal 5 times, the check engine light flashes.... but it is different each time.... how do you read the code.... it flashes then goes out for a second or so, is that second the division between code numbers? and if i do get the code, where can i find out what it means.... just call the dealership, or what?

[bmwe3]

check engine light

turn the ignition on not started pump gas 5 times with the same pace the check engine light will flash on pause on on on on pause thats mean the first 2 numbers are 14 if there are no codes it will be 1444