Newbie. E39 problem - BMW Forum

stig101 · 03-13-2006, 12:34 PM

Hello all.
New to the forum,well

I have been here for a while but not registered till now

.
I own a 1999 E39 528i for about 3 months now , great car. but I have been having some problems I'll appreciate any help with. check engine light it just keeps coming back every time I erase it with no error codes what soever , I have read from previous post here that it could be an air pump issue

(where is the airpump )or an o2 sensor ? but if it is should'nt I get an error code ?
thanks for any help .

325isBaby · 03-13-2006, 03:52 PM

If you believe it is the air pump it is located on the right side of the engine compartment (could be next to shock tower) and looks like:

stig101 · 03-13-2006, 04:27 PM

325isbaby thnx for ur reply what is this airpump for anyways , and is there any way I can check it if it is bad.

thanks again.

LOS · 03-13-2006, 04:33 PM

Just wondering, how many miles on your car?

LOS

stig101 · 03-13-2006, 04:49 PM

about 78000...
LOS do you think it could be the o2 sensor? I do suspect it is that but the car runs fine and the m/Gallon is spot on ...

CosmosBlack · 03-14-2006, 06:10 PM

A good bet is the Mass Airflow sensor, if that has not been replaced yet.
It's about a $400 job.

LOS · 03-15-2006, 09:26 AM

http://www.bimmerzone.com/fcodes.htm

As you know, our cars have 4 sensors. I only replaced 2 when I hit 78k. My light did come on and got a code... Are you using the righ tool? The peak reader costs around $150. checkout the link above for codes.
Even if it was the mass flow sensors, you should get a code on your reader! Right?

Also, check autohausaz.com if you decide to buy the sensors. they usually have good prices on parts.