5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
Folks, I need some diagnostic help, and so does the car.
I've a 2002 530i that idles poorly and stalls at traffic lights. Actually, I've not experienced the stall but my wife has several times. I will attest to the rough idle. I used my Peake scanner and I get two major codes:
1. O2 Adaptation Limit
2. O2 Sensor Control Limit
There are a series of misfire codes for all cylinders but I thing these are the result or symptomatic of the above two.
Also, there is a sharp metallic or clacking sound underneath the intake manifold that is periodic. Sounds like a very loud soleniod action or perhaps a backfire.
The car has 120K on it so I've recently replaced all four O2 sensors and the plugs. Recently I found the rubber vacuum line to the Secondary Air Diverter Valve cracked so I replaced it and traced it back and replaced at the opposite end as it was also deteriorating.
I've also put a new throttle body on the car for another issue.
I really need some help with this. Thanks I appreciate it and so will my wife as she is now driving the old cherokee and wants the 5'r back.
I should have suspected that. I unplugged the MAF, the engine quit andI restarted. Smooth idle and no solenoid on steroids sound.
I recently replaced the MAF on my VW TDI. Those give you a pretty good sense of their failure. They start to slow down until the performance of the TDI rivals that of an old diesel rabbit; my old vw bus was faster (for a frame of reference). Unplug the MAF and it goes like a real car ought to.
I just wonder why there is no MAF code on the BMW or the VW. It must be a German thing.
I have exactly the same symptoms on my 2001 with 140K, including the solenoid on steroids noise. Did replacing the MAF solve the problem? That's a $400 part! Is the a way to test it to confirm it has failed?
Rough idle update. When working my way into the ICV for cleaning I noticed my intake manifold runner valve was damaged. It was not longer connected at the actuator end of the flapper. I replaced the part last night and when I started it up, it purred like a kitten. Problem solved. Thanks for the DIY stuff that lead me to clean the ICV and ultimately to the root cause of the idle problem. I wouldn't have gotten to it without BimmerWerkz to guide me.
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