1996 328i Check Engine Light

[khult]

Dear Bimmer Gurus --

I have found many partial answers to this question on this site and others, but nothing seems to tie everything together into a definitive answer...

My 1996 BMW 328i's "Check Engine" light is on, but everything seems to be running well.

The first thing I did was check my gas cap, which, in fact, was slightly loose. I have driven around 40 miles over four days since then, but the light is still on.

So I'm starting to guess that something more sinister is at work here. So lacking a diagnostic tool to formally check the error codes, is there a way to have the car tell me? I know that other older models would blink the codes if the accelerator was depressed five times before starting the car.

So is there a trick that might work with my car, or am I stuck paying a dealer a ton of money to spend two minutes to plug his tool into my car?

Thanks in advance for any help you can offer.

Kjell Hult

[LmtdSlip]

Being that your car is a 1996 it is probably OBD II and will require the use of a tool to determine the error.

Most likely it's your O2 sensor. Has it ever been changed?

This link will show you all you need to know about determining the fault that is causing your light to come on.
Error codes (http://www.pelicanparts.com/bmw/techarticles/Mult-Code_Reading/Mult-Code_Reading.htm)

If your car is an early build 1996 you may try the OBD I method to decode. Otherwise you will have to buy/borrow/pay for use of a toool to decode the fault.

By the way...Welcome to the fest

[jvr826]

You can go to auto zone or pep boys and have them read the codes for you for free, check their website and call first. I'm not 100% sure who does this for free.

When I had a 1996 my cam position sensor went, it was a known problem for those I6 motors. I also had it replaced in my 1999 528i with the same motor. One the '96 The initial symptom was just a CE light, but soon after the engine started bucking and chugging. I limped in just in time. All was perfect after it was replaced.

If your gas cap was loose, then the light may reset by itself, but it will take more than a few starts of the engine to get that to happen as I recall. Don't remember the range, but it was more than 2 or 3 IIRC.

[Bmwcat]

There may be a problem with emissions controls. Could be a sensor or hose. I had the same thing in my 328. Repairs may not be a lot of money if your mechanic is honest. I'd avoid BMW dealers...good luck! :p

[JRacko]

1996 is OBDII you need scan tool.

I have 96 328i and I have fault in secondary air system of cylinders 1-3 and 4-6. Anybody had that problem or know what to do?

Thaks.

[patelpk]

I just had my 328 checked as the check engine light came on. The codes the mechanic gave me were 251 and 254 Tank-leak detection: minor (major) respectively.

They told me 2-3 hours of labor to pressure test my fuel system and see if there is a leak and possible $200 in parts. Anyone run across this before? He also said maybe i have a 'miss' in my engine and it could be caused by this as well.

He reset the light and i drove home and decide to check this board. it didn't come back on while driving home. time to call a few other mechanics i guess with the error codes and see what they propose.


ok, so i called 2 more places, the dealership and a retired mechanic i use now and then. retired guy said change the gas cap and make sure that is on right, if that doesn't help bring it in. the dealership first said $190 labor to pressure test my fuel system and see if the canister is bad. i said what else could it be, then he said check the gas cap and see if it goes away in 4 days at most.. if not bring it in for the pressure test.

I asked if it is a major thing, he said not dangerous but since the fuel ration will be off, my emission will get worse over the next few weeks if the pressure sensor, canister or other things are bad....

I hope this helps someone else avoid $400 in labor and parts for testing something or overly worring about an issue that can wait a week of home diagnosis..

P

[khult]

I finally found a friend with a scan tool and borrowed it for five minutes. As it turns out, i apparently have a short in my catalytic convertor. The car continues to run perfectly and there is no blue smoke or other sign of an emissions problem. I was able to turn off the light with the tool.

Thank you everybody for answering my question and weighing in on likely culprits; I very much appreciate your help.

Kjell

[ImperialDuckM3]

A short in the cat :dunno: I don't know what kind of tools was used.

But all of those mechanic are bunch of B.S. Since you left your cap off, yes it will throw your CEL. But ususally it will go away by itself (self fixing error).