BMW Gurus in Northeast Georgia

[jdm333]

I've pretty much thrown in the towel on getting my 1998 BMW 740il running right so I'm looking for a good independent mechanic near Gainesville.

It was running fine until one day it started missing and backfiring. It will barely idle and if you try to rev it it will sputter and backfire.

I've replaced the cam and crank position sensors but I believe the intake needs to be pulled so all of the gaskets can be replaced. I'm looking for someone to properly diagnose and repair the car. Let me know if anyone here has experience with this type of car. It is the m60 engine and it is not throwing any codes.

 

[Lobo1]

Sounds like it has jumped time on you

 

[Gunfighter]

Lookup Bimmers South in Athens.
They'll hook you up!

 

[Dawgbrain]

These guys are in Braselton and have treated me very well in the past...
http://www.strictlygermanonline.com/
http://www.strictlygermanonline.com/

 

[jdm333]

Never thought about it jumping time but that does make sense. I was thinking huge vacuum leak based on common issues with this engine but timing does make sense. I replaced the sensors that control timing but didn't think about timing belt issues. I'll have to pull a plug and find tdc to confirm.

 

[jdm333]

Sounds like it has jumped time on you

Thanks for the pointer on timing. It thankfully didn't jump time but I did replace a faulty crank position sensor with one from Advanced Auto. It didn't fit just right but I didn't realize it since it is under the car near the bell housing.

I pulled it back out and compared to the original. There was a slight difference in the depth of the sensor and I was able to remove some material and make it work. I'll be replacing it with one from bmw vs aftermarket. The tip off that the sensor was bad was that the tach wasn't registering any RPMs when it was running.

 

[Lobo1]

Thanks for the pointer on timing. It thankfully didn't jump time but I did replace a faulty crank position sensor with one from Advanced Auto. It didn't fit just right but I didn't realize it since it is under the car near the bell housing.

I pulled it back out and compared to the original. There was a slight difference in the depth of the sensor and I was able to remove some material and make it work. I'll be replacing it with one from bmw vs aftermarket. The tip off that the sensor was bad was that the tach wasn't registering any RPMs when it was running.

We'll I am glad it didn't jump time. That's a headache on a BMW more so than other cars. I didn't mention the cam position sensor since you mentioned you had already changed it out. But your right. The tach in it picks up a milliamp signal that is supplied to the CPM from the cam position Spenser. Kinda like an encoder and the pulses per revolution it produces. Glad you found it and I hope you get many more miles out of it.

Edited to add: I kept referring to cam pssition. I meant crank shaft position sensor. My bad. Long day

 

[Wallace's]

Sounds like it has jumped time on you

Ummm, may have some bent valves from that.