Hi,


I just wanted to let everyone know what happened to my new broken wagon.

I pulled off the cylinder head this evening and found out what caused a misfire on the forth cylinder.

A piece of the exhaust valve flew off and passed through the wastegate without impacting the turbo impeller. NEAT!! :)


I will post pictures later.


Goatman

I am very curious to see the pics. I wonder if the PO had iridium or platinum multi prong plugs with a missing prong? Something caused the valve to break and might have caused a dent in the valve seat???

Klaus
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Praying for Cynthia Amendt, heaven bound

I had the exact same problem when my 850 was fairly new--I had put in platinum plugs and the only thing we could figure (dealer shop didn't check the corresponding plug) was that a piece of insulator came off. I have heard others say this can be a problem, so I went back to standard copper plugs with no further problems.
--
96 850T, Bilstein HD, IPD swaybars-HD endlinks

Good call on the tear down then. Lets see those pics.
--
'97 855na, Mobil 1, K&N, various IPD's and eBay's

Hi,


I got the head tore down and it is pretty obvious that the previous owner used the cheapest fuel she could buy.

I believe that detonation damaged the valve during boost. This is how the piece was able to exit the engine through the wastegate. There was no engine damage other then the fractured valve.

http://www.unm.edu/~goatman/valve.jpg
http://www.unm.edu/~goatman/engine.jpg

Please don´t hesitate to ask any questions!


Goatman

That's quite a large piece missing. I agree that she used 87 octane, but the valve piece could have easily gone through the turbo vanes without any damage. Those vanes move at exhaust flow speed, so now there is a piece of valve in the CAT :)

Cleaning will be a chore! Number the board 1-5 in the center of each valve group, just in case it gets turned around by someone. The head looks pretty good and flat. New stem seals should be used.

Just before you put the head on, add a little motor oil to the rings for an aid to restart.

You are doing good. The $600 850 never responded to my email, I assume someone else is now driving it.

Klaus
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Praying for Cynthia Amendt, heaven bound

>Please don´t hesitate to ask any questions!

So ... how did you finally manage to get the head off? Looks like this project is going to keep you busy for awhile! Good luck with it.
--Bud

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'96 850 and '83 244 DL both at about 200K; gone but not forgotten '81 245 and '64 Amazon

Hello,


I attached some chain to a slide hammer and engaged the links to the protruding tabs on the camshaft cover.

http://www.unm.edu/~goatman/tabs.jpg
http://www.unm.edu/~goatman/tackle.jpg


Goatman

Nice, but it doesn't look like goatman's helper is a sheepdog ;-)

--
'96 850 and '83 244 DL both at about 200K; gone but not forgotten '81 245 and '64 Amazon

Awesome. Can you post pics when it's all nice and clean and going back together, so I can live vicariously? Just think how nice it's going to be. I hope you're replacing all the PCV parts and putting synthetic oil in.
Klaus he's got his board labeled front in the pic ;)
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'97 855na, Mobil 1, K&N, various IPD's and eBay's