# All 6 cylinders misfiring!!!!



## Bimo135i (11 mo ago)

Can anybody help me I’m don’t know anymore what to . My car was running excellent then there was a small oil leak coming from valve cover, so I replaced the gasket but I screwed up the gasket wasn’t properly seated when I started the car it was leaking oil all over . So replaced the all 6 coils and spark plugs new gasket then reinstalled it. This time no leaks anywhere but engine is running loud than usual idling is rough and when I step on gas the engine is loud and I hear a whoosh sound.. the also has a check engine light on.. the mechanic I talked to said it could be the valve cover need to replaced it. Is he right? Why do I have to replace the valve cover if there was no leaks. Can someone please help me on what I need to diagnose. Any input is greatly appreciated.


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## ThisOldBob (Sep 13, 2021)

Do you have a reader to read the codes? Specific codes may help to troubleshoot.

I'd start by checking the connectors. I know when I put new coils in my car, I ended up with a misfire. I found that one of the coil electrical connectors was not fully seated. Those little clips on the coils are pretty cool but they are not stong enough to always pull the connector in tight. I tried with the clip several times and didn't make a difference. Pushing the connector in hard while lowering the clip seemed to do it. 

Other things to check - there are two ground wires on the coil harness that go to the center valve cover bolts, make sure those are on and tight. Also check the hose at the back of the valve cover. 

The only reason I could see that the valve cover would need to be replaced besides cracking is that there is a ventelation diaphragm built into the valve cover that could tear. I don't think that it would cause misfires but will cause a wistling noise. Lots of posts and youtube videos on it. There's also a possible cheap fix available which involves cutting off the old one and epoxying on a new diaphragm. 

I'm in N52 land though and not sure all those apply to N54/N55.


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