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Check Engine Light Codes - HELP!

3K views 6 replies 4 participants last post by  chrisn7 
#1 ·
I have a 2001 BMW 740iL that has about 150,000 miles on it.

My check engine light keeps coming on so I went to the auto parts store for a free test. Here is what came back.

P0300 - Random/multiple cylinder misfire detected
P0301 - Cylinder 1 misfire detected
P0302 - Cylinder 2 misfire detected
P0303 - Cylinder 3 misfire detected
P0305 - Cylinder 5 misfire detected (Reported Fixes: Catalytic converter(s) replaced with P0306, P0308 - Ignition coil pack(s) replaced with P0306, P0308)

P1159 - Fuel Trim Adaptation Additive High (Bank 1)
P1161 - Fuel Trim Adaptation Additive High (Bank 2) (M52: Engine oil temperature sensor circuit)

Both of the cam shaft sensors have been replaced twice but we are still getting the check engine light. I was also told that it sounds like it might need the timing chain replaced. I about fell over when I was quoted $8,000 to fix that and they were not even sure if that was the issue.

Now we are also experiencing clicking when trying to start. I had noticed that the interior lights were coming on and off without touching the key or the car & the doors would lock & unlock on their own as well as when I would try to get into the trunk. We are getting a new battery since it will no longer hold a charge but am worried that there is a short somewhere in the alarm system that keeps draining the battery.

Any idea's or suggestions as to what needs to be done would be much appreciated!
 
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#2 ·
Everyone and their stupid quotes. Fuel trim adaptation is either O2 sensor or vacuum leak, but it sounds like you have a bad vacuum leak causing misfiring. Also a weak battery WILL cause misfiring. Its happened to me. Shorts can be found by removing the positive lead but leaving the negative than using a multi-meter. Put the positive side of the multimeter to the positive lead from the car not from the battery terminal, and than put the negative on the battery/terminal. If it has a reading there is a short. Fuel trims are almost ALWAYS vaccum leaks. Start with getting a can of brake cleaner, start the car, and spray around manifold. Listen for idle changes. Idle changes mean vacuum leak. And that shop who quoted you 8,000 is FU&KING YOU. I would've laughed. DEALER isn't even half that cost. Your start up rattle is 70% the side tensioner in the passenger side timing cover. Easy and cheap to replace. They've been updated because the springs weaken and compress. I paid 800 in total for all my timing parts and 300 for VANOS timing tool set. So 1100 and replaced all my timing stuff. This included coolant hoses, manifold gaskets too. That shop would've made HUUUUGE profits from you at 8k. Labor on that job is like 21-hours which comes out to no more than 2000 for the job.
 
#3 ·
Thank you for responding to my post! I will have to check out the vaccum leak and get that fixed. I hope I can find and repair the leak quickly. If it is not a vaccum leak how do you change & where is the 02 sensor?

As far as the battery goes, we have already replaced the battery and still have the same problem. I will get a multi-meter and test it out. I have asked a few people and they seem to think by disconnecting the alarm system it would stop the short but they also said it may cause the car to not start.

I am more use to fixing older "muscle car" issues so vehicles that are mostly computerized I am clueless on.

The shop that gave me the $8k quote was a BMW dealership. They said they would have to completely remove the engine to get to the timing chain and replace it. I had looked up a DIY on it and it was done without removing it. My husband was the one that got the quote & I had called to confirm the quote & to find out exactly what they were going to do. It sounded like we were getting screwed right from the get go so I cancelled the appointment my husband had made.
 
#4 ·
Thank you for responding to my post! I will have to check out the vaccum leak and get that fixed. I hope I can find and repair the leak quickly. If it is not a vaccum leak how do you change & where is the 02 sensor?

As far as the battery goes, we have already replaced the battery and still have the same problem. I will get a multi-meter and test it out. I have asked a few people and they seem to think by disconnecting the alarm system it would stop the short but they also said it may cause the car to not start.

I am more use to fixing older "muscle car" issues so vehicles that are mostly computerized I am clueless on.

The shop that gave me the $8k quote was a BMW dealership. They said they would have to completely remove the engine to get to the timing chain and replace it. I had looked up a DIY on it and it was done without removing it. My husband was the one that got the quote & I had called to confirm the quote & to find out exactly what they were going to do. It sounded like we were getting screwed right from the get go so I cancelled the appointment my husband had made.
That's non-sense. It would be even cheaper to get a replacement used motor with less miles, and buy all the timing parts. Those motors run anywhere from $ 2,000-2,500 with decent mileage. The O2 sensors you would want to replace are the Pre-Cat sensors which are Bosch 13559 run about 60ish at AutoZone. Definitely help with fuel economy anyway. Its recommended replacing those at 100,000 miles. It would be nice to get that car scanned with DIS/GT1 or better AutoLogic computer which will point out whats wrong. Usually BMW specific shops will have those. It could also be bad coils. You could check those by running the motor and pulled the coils out and listening for spark. That's not too hard to do. Just remove the 10mm nuts holding the coils down. Take a video, I'd like to hear/see whats going on
 
#5 ·
I will have to do that for you. You may end up hearing something I dont. Pulling the coils out it looks like there are 8 of them on this engine (one for each cylinder)?

Also the digital display needs to be replaced. We are not able to read anything on it regardless of it saying fluid is low or a bulb needing to be replaced, we cant even read the exact miles on the car. How difficult of a job is that if I can find a used display at a salvage yard (may just get brand new since they do not guantee electrical parts).
 
#6 ·
I read some where (a Dutch site Ithink) that the display can be fixed by cleaning some contacts behind the unit.
 
#7 ·
1) Remember that when doing a battery drain test, you must wait at least 16 minutes for the car to go to sleep. Open the boot, use your ignition key to close the latch on the lid (simulate closing), then wait. Here's how to do the test:
http://www.meeknet.co.uk/e38/E38_Battery_Drain.htm

2) Take care working with coils-they are not marked High Voltage for nothing

3) Pixels are fixable and here is (the Dutch) fix:
http://www.bimmerboard.com/forums/posts/543597
-however, with utmost respect to your skills, unless you are confident and can apply a delicate touch, this may not be for you. If you attempt it, do not under any circumstance remove the needles to the dials, however tempting this seems-as this will result in a scrap cluster.
 
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