misfire codes - removing cylinder head

[adamc]

So the '04 (16k miles) had a bit of a rough idle in the mornings. I wasn't thrilled about it, but it seemed to warm up pretty quickly and run fine. Thought I was slowly on my way to the ETM issue. A few weeks ago I got a check engine light. Took the car in, I had run the gas tank pretty low, they said I probably just got an air bubble or piece of sediment that caused the misfire. No big deal, sent me on my way.

A couple of days ago, got another check engine light. Dealer said they were going to keep the car so they could do compression tests this morning when engine was stone cold. I guess the tests weren't good because the service advisor said they're on the phone with Volvo, and Volvo is recommending to remove the cylinder head. I assume for further investigation, although the service advisor didn't explain more.

I'm quite nervous that they're already having to take apart the engine at 16k miles. Only used premium gas. 1st oil change at 3.5k. Amsoil at 7.5k.

Anyone else heard of/experienced this?

[gibbons]

Man, this sounds like a post from the Subaru forum :) Sorry, that's not funny.

Can you tell us what the compression readings are? Maybe we can all take an uneducated guess on how you stand. Removing the head isn't that big of a deal, heck, even I have done it. But I would want a thorough explanation of what and why first. I think I would be apt to say, "eat my shorts, I want a whole new engine".

[adamc]

I'll call the dealer in an attempt to get compression test readings. They're "guessing" it's a stuck valve that's remaining open.

Your thoughts that I should ask for a new engine have me concerned...

[tgrumaj]

adamc
What happened and how if was finally fixed. Was it a stuck valve? Bad gas? or just a prelude to the ETM failure? I've got a similar issue on my 99XC.

[adamc]

Ok, so the latest is that the dealer replaced the entire cylinder head assembly and all the valves. Car is back in our posession and seems to be running fine.

All that was on the documentation was that the compression test found the cylinder 5 was not producing spec compression. On the phone the dealer said they had to call Volvo for recommendations on what to do, Volvo recommended replacing cylinder head and valves. It definitely seems like a guess and check job. I never got a definitive answer as to what the specific problem was.

Does anyone (possibly Art) know how I can get the part number for the cylinder head? The documentation says they replaced the cylinder head and all associated parts, but I don't see a new cylinder head on the parts list, just valves and gaskets.

[bob]

A number of engines were produced with "too soft" valves, and after a time the valves would fail to seat properly, causing a missfire. Repair is to replace the faulty valves.

[Jack]

My copy of VADIS list these for the head:

8601962 REPL 1PCS 8251136-1
8251136 -2004 EXC B5254T2
8602773 2005- EXC B5254T2
8602635 B5254T2

[tgrumaj]

Took mine to the dealer today due to the misfiring issue (cyl. #1) and it was......a pinched wire. When my mechanic had done a replacement of the spark plugs he tightened the cover back on an prinched a wire to the coil. As it heated up when running it would short out causing the cylinder to misfire. Still not cheap but a lot less than it could have been...sometimes even I get lucky.

Good luck adamc I hope you get to the root of your misfiring issue.