Valvetronic Info

[c362137]

I just bought an 2008 750 a few weeks ago. We were driving it home and it started running like shit. I put the scanner on it and it had a misfire on cylinder 7.

Pulled the coil and it was covered in oil. Check all the others and they had oil too, so I changed out the Valve Cover gaskets and Spark Plug Tubes. So I put it all back together and I swapped #7 and #6 coils to test if the coil may have been damaged from the oil.

The car ran like shit. Put the code reader back on and now #6 is misfiring, so I got a new coil coming.

My trouble is, it seemed like it was running shitter than just one cylinder misfiring. I'm worried if I need to relearn the Valvetronic motors? I twisted them all the way down when I put them in, and when I took them out they were all the way out. When I took the last bolts out of them they popped out.

Do I need to have it hauled in somewhere to get them relearned or I've read about just turning the key on for a bit and they relearn themselves.

Thanks for any input.

[White94RX]

I responded in the other thread. No relearning necessary. Put the key in and start the engine.

[c362137]

Alright, got the coil in, valve covers changed, spark plug tubes changed...… Hopefully those damn tubes don't leak again.

Now I have multiple cylinder misfire. I've order a set of new plugs, the old ones didn't look so hot (108k miles). Is there a way to test the coils? Several of them had oil on them when I tore everything apart. I hate to buy all new ones without somehow testing the old ones.

I know I have fuel pressure. While trouble shooting I disconnected the fuel line to the rail and fuel spurted out. So it was under pressure. I guess the injectors could be screwed up, but coils seem more likely.

[White94RX]

Recheck your work. I've seen valve covers not bolted on flush with the head causing large vacuum leaks and misfires. I always remove the reddish plastic line-up things on the underside of the covers.

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[c362137]

Actually, I had to redo the left side. I went out yesterday to work on it and there was a puddle of oil in the driveway. I high temped RTV'ed everything this time, plug tubes too.

I took those plastic things off. They were cracked and I was afraid of them breaking off. I couldn't really see what they were for.

I ordered Delphi coils and Bosch plugs. If this doesn't work, I'll try redoing the right side cover. Those things are such a bitch I'd rather spend the $200 buck on coils and plugs than redo them.

[White94RX]

Are you using OEM parts? Replacing the rubber grommets? You noticed the hold down nuts are different sizes, right?

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[c362137]

I'm not sure about the gaskets, tubes, and rubber grommets. I paid a lot for them ($140) assuming they were OEM. They seemed like shit when I got them though. Actually, when I redid the left side I reused the old gasket I took off. I looked new. It seemed like someone had told the previous owner it need the valve cover gasket and they changed only the gaskets and not the spark plug tubes or grommets.

Yes the lower bolts are the short ones, and the hardest for me to get in. I'm always paranoid of dropping them and loosing them who knows where. Then the top two have the grounding points on them.

I got the new plugs and coils (OEM) today. I'll go out Friday and look at the whole deal again (busy with work). My big concern is oil in the tubes, but now you got me worried about the gasket/vacuum. I'm thinking if I find any oil in the tubes I'll bite the bullet and do the whole job again

My big concern now is messing up the new coils with oil contamination.

I hate doing those damn things, but at this point I'm getting faster at it...

Thanks for the help. Do you think I should just go to the dealer and get new gaskets/tubes/grommets?

Thanks again.

When it's all done, I update this.

[c362137]

How can I check if the valve cover is causing a vacuum leak? I can't find any oil leaking out....

OEM Coils and plugs didn't work.

[White94RX]

A smoke test will find vacuum leaks.

[c362137]

Got the car fixed finally and I wanted to let everyone know what I found just in case they are having problems too.

After installing new plugs and coils, and after doing the valve cover gaskets it still had multiple cylinders misfiring. I used Bosch plugs and coils not sure about if the gaskets were OEM or not. I want to note that above I mentioned I used Delphi coils, but turn out they weren't the right coils for my year of car. I returned them and bought Bosch.

Turns out three of the coils had rubber that wasn't properly cut away from the contact point up inside the coil. The rubber was keeping the coil from making proper contact with the spark plug. You would have thought that buying the Bosch coils that they would have been properly made, but no.

If this doesn't fix your problem, good luck to you.

[White94RX]

Glad you got it fixed. Here at the dealership, any coil that gets replaced is replaced with a Delphi coil. They are the upgraded replacement part from BMW. They don't even use the crappy Bosch coils anymore.