zero Compression in cylinder 8

SS1M3 · 02-11-2019, 09:39 PM

I had misfire in cylinder #8 on my M3 09 with 75k and had oil change two weeks ago. I was at the traffic lights and notice the RMP going up and down. later more vidration and car went to limp mode with “reduce power light on”
It went to the dealership, they swap coil and spark plugs and still misfire.
They a compressions test and Zero pressure in cylinder 8. the will remove the engine cover tomorrow and hope for a damage valve or spring.
I hope that this is not the end of this engine..

does anyone have any suggestions to diagnose the issue?
Who can rebuilt an engine?

Helmsman · 02-12-2019, 05:34 AM

Sorry to hear mate. Possible advice here: https://www.m3post.com/forums/showthread.php?t=1582566

pbonsalb · 02-12-2019, 05:43 AM

I assume the dealer has given you a diagnosis. The single cylinder issue might be a broken valve spring. It’s not common but has happened to a few cars. If the rod bearing was spinning rather than the rod moving, there would be a lot of friction and I think by now, given all the testing that has been done with the engine running, you would have bigger problems than misfires — the engine would be locked up and/or ruined.

As noted in the other post, there are good shops around the country that rebuild these motors if you need a rebuild. I am not sure you do but you will need some repair work. I’d rather give it to one of these independent shops than a dealer.

02-11-2019, 09:39 PM	#1
SS1M3 Private 1 Rep 54 Posts Drives: 2009 M3 E92 6 speed Join Date: Feb 2014 Location: Houston TX iTrader: (0) Garage List 2009 BMW/ e92 M3 [0.00]	zero Compression in cylinder 8 I had misfire in cylinder #8 on my M3 09 with 75k and had oil change two weeks ago. I was at the traffic lights and notice the RMP going up and down. later more vidration and car went to limp mode with “reduce power light on” It went to the dealership, they swap coil and spark plugs and still misfire. They a compressions test and Zero pressure in cylinder 8. the will remove the engine cover tomorrow and hope for a damage valve or spring. I hope that this is not the end of this engine.. does anyone have any suggestions to diagnose the issue? Who can rebuilt an engine? __________________
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02-12-2019, 05:34 AM	#2
Helmsman Major General 4465 Rep 7,109 Posts Drives: 2011 AW E90 M3 ZCP Join Date: Mar 2014 Location: Stockholm, Sweden iTrader: (0)	Sorry to hear mate. Possible advice here: https://www.m3post.com/forums/showthread.php?t=1582566
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02-12-2019, 05:43 AM	#3
pbonsalb Lieutenant General 5231 Rep 10,614 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	I assume the dealer has given you a diagnosis. The single cylinder issue might be a broken valve spring. It’s not common but has happened to a few cars. If the rod bearing was spinning rather than the rod moving, there would be a lot of friction and I think by now, given all the testing that has been done with the engine running, you would have bigger problems than misfires — the engine would be locked up and/or ruined. As noted in the other post, there are good shops around the country that rebuild these motors if you need a rebuild. I am not sure you do but you will need some repair work. I’d rather give it to one of these independent shops than a dealer.
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