Quote:
Originally Posted by MrFixIt
Welcome and congrats on your new X5. We have the same model and year. Mine has 135,000 miles.
Misfires might be caused by loose electrical connections since it ran fine for 500 miles:
1. Check to see if the ground wires between coil #2/3 are properly connected/secured.
2. Check all connections (coils and electrical plugs to coils)
3. What type of plugs are installed, age/mileage?
4. Check fuel injector electrical connections.
5. Check cam wheel position sensor electrical connection.
6. It's doubtful that all four coils one bank 1 went bad at the same time. But to check it, you can switch one with bank 2.
Bank 1 cam position code? Is it P0011?
1. What's the mileage on your X?
2. Might be related to cam position sensor (try switching with Bank 2) or it could be that the timing on Bank 1 is off (chain skipped a tooth?)
3. Are/were there signs and symptoms of failing chain guides, like grinding /crunching noises?
I've just recently replaced all the plastic chain guides as preventive maintenance, they were so brittle and some had already broken off. The X had to no fault codes, but I'm glad I replaced them before the impending catastrophic failure. Now I'm in the process of retiming the cams(had P0011 code)--with a different set of timing tool. Hopefully it will be good to go this time.
Just take a good bright flash light and start your investigation. You have all the maintenance history on the X--very important? I'm wondering what else was done on it besides valve covers. Did they replace the upper timing cover gaskets as well?
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Thanks for the reply.
Vehicle has 98,350. I purchased from local dealer vehicle was a one owner no maintenance documentation. Dealer replaced valve covers at 97,800.
1. Checked and verified loose connections none present.
2. Plugs are BMW bosch 4 prong. Look aged and will replace them.
3. Fuel injection connections good though will be removing clips and box again.
4. I found oil in the plug hole for Cylinder 4. Saturated the plug and boot. Then upon removing the coils and plugs from 5,6,7,8 all but 5 have oil soaked plugs and boots.
I am going to replace both cps with bmw replacments, new plugs, 4 new coil pack boots, and both right and left valve covers again.
No crunching noise or signs of failing guides. I have heard the horror storys and the video footage of a bad guides. No upper timing gaskets seem to be replaced.
Quote:
Originally Posted by racingbmwm3
Agree on swapping cam sensor with bank 2, and double checking the ground connections. Just to verify, you are looking at the passenger side of the engine correct? Bank 1 - passenger, Bank 2 - Driver.
It should be very difficult to get the coils plugged in wrong, but verify that all the wiring going to the coils look nice and neat. All the coils are bolted down snug?
Harness from firewall looks ok, no cracks/tears/rodent damage?
I'm not so sure that the problem would be with the gasket itself, otherwise you should be getting mixture faults also. Most likely a wiring issue, but it could also be related to the cam sensor.
Also, nobody has mentioned this yet, but that first fault sounds like your thermostat is dead. do yourself a favor and disconnect the thermostat and inspect the connector for a coolant leak. The v8's had a tendency to leak coolant through the connector into the main wiring harness and over time coolant could travel all the way back to the DME. So if you have any coolant inside the thermostat connector, I'd check the DME next and look for coolant there.
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Thanks for the reply.
Yes working on bank 1 passenger side of engine. Coils were plugged in correctly and all injector clips were connected. I could not pull off the wire box without disengaging the fuel injector clips. No damage to the harness.
Serious amounts of oil present in 4, 6, 7, 8 plug wells.
Im thinking a combination of the old plugs and the failing cps is causing the misfires. But I need to remedy the oil issue in the vc.
I have a thermo on order to repair this issue. I checked the connector per your request no coolant traveled up through the wires or connector.
I have to fight this one still under the 30 day 1000 mile warranty. Since I have experience with repairs she didnt want me to take it to a repair shop. I need to work out details to get her to reimburse me for my labor. I have 2 hours in ts already wrapped in this thing. Never expected to have these problems 5 days into ownership.