Does this sound like a burnt valve?

[erikv11]

Don't touch the cam seals until you put it back together. You're going to want to replace all top end engine seals anyway.

Pull the cam cover and cams.
Pull the head. Loooonnnng breaker bar no impact tools.
Observe hole in burnt exhaust valve.
Find a local machine shop people trust. This is important, there are plenty of hacks out there.

Parts needed for next step:
Replacement exhaust valve(s) from p80 turbo head. I would get used one(s).
Full set of Volvo branded valve stem seals (you need 20; get the 24-pack).

Have the machine shop do:
resurface head
clean cam cover
replace all valve stem seals (must be Volvo branded)
reseat all valves
This will run 300-500 depending on where you live, their mood, etc.

Clean the block surface. Don't warp it or gouge it. No sandpaper!

Parts needed for next steps:
head gasket
new head bolts
all new cam seals (no Elring parts - Corteco)
spark plug tube seals (I'd buy from Volvo, up to you)
timing parts if it is due
anaerobic gasket sealer and little roller
ignition parts if it is time
PCV parts if it is time
intake manifold gasket
throttle body gasket
t-stat housing gasket
gasket for that PITA cooling pipe hole in the back of the head
exaust manifold gasket
turbo cooling hoses if they have never been done
Turbo oil drain return gasket and o-ring
all engine bay vacuum lines that haven't already been replaced.
other part(s) I forgot to list

Put it all back together.
The tutorial from the Tracey's True Soaps guy is the gold standard.

This will end up costing $700 ut you will have a brand new engine, assuming the rings aren't bad. The bottom is very hardy, the rings are probably not bad.

[Jazzer]

Thanks for the list; I have definitely been studying Tracy's write up as well as Robert's videos. The gasket kit is in the mail from FCP, and I'm picking up all the odds and ends over the next few days. A well-rated machine shop near me will do the head cleaning and valve job for around $270, which sounds pretty decent. Can I put new front cam seals on without taking off the sprockets? Or can I pull them over the cam lobes?

[erikv11]

Yeah, once the cams are out you can put the front seals on by wiggling them down over the lobes. I've done it that way, in fact have always left the sprockets on unless i wanted them off for something.

That's a good price on the head and valve work, nice. We're not just being snobby about the Volvo valve stem seals, it will be the best $80 you ever spent, buy them in the blue box. You don;t want to have them leaking in 14 months.

[Jazzer]

Well guys, I'm back... and I finally had a chance to dive into the head. 8 hours later, and I finally finished the disassembly; for those that guessed a burnt valve ( and that's pretty much everyone), you are correct! It did run smooth at higher speed, though. Anyways, here are a few pics of the cylinders and valves. Anybody have a good idea for cleaning up the top of the cylinders? They look like a bad oven in need of Easy Off...

[erikv11]

Chippy chippy little chip (not sure what that means, if anything ...).

Some people will say to not clean the pistons. I like to clean the tops, here's what I do: raise the piston to the top, coat a couple of flat layers of paper towel with a good carb cleaner (my favorite is B-12 Chemtool), lay the paper towel on the cylinder, then put a small pane of glass over it to stop the carb cleaner from evaporating. I use glass because I happened to have some in the garage when I first needed to clean a piston but anything flat that stops evaporation would do, e.g. a piece of flat sheet metal, etc. The glass needs to be wider across than the cylinder and its sleeve. Walk away, leave it 10-15 minutes, when you come back the majority of the crud will wipe right off. Do a second round if you need it, you probably will with those.

Then turn the crank until you raise the next piston to the top, and go to work on it.

Make sure your work space is well ventilated, otherwise the cleaner will get you dizzy in a hurry.

[rspi]

Those piston tops are the worse I have ever seen. As they said, DO USE VOLVO valve stem seals, ask me how I know... Doing the head job the 2nd time is a lot less fun than the 1st.

As for the build up on your pistons, what's going on there? My guess is that you have a PCV issue or the turbo is blowing oil into the intake.

What fuel do you use?
What oil do you use?
Was the PCV in need of replacement?
Does the turbo have shaft play?

[Jazzer]

Yes, I agree that they look quite horrible. The previous owners (I'm the 5th owner, ugh) did not service the pcv system (ever) and I did it about 8k ago at 180k miles. The damage is done, though: oil seeping out of pretty much every seal. As far as I know, the turbo is ok, though that will get my attention after all of this. I've been using 91 octane since I got it, along with Mobil 1 10w30. The first owner really babied her; I have the original service records with the dealer stamps in the maintenance book. After that, though, she was neglected. I'm slowly bringing it back to life..

[rspi]

I wouldn't clean that off but I'd try running some injector cleaner through there every 1000 miles and check it after 10,000 to see if they clean up any. Put one of those cell phone scopes through the spark plug hole on #4 since it looks worse.

[abscate]

You can send your head to Kally for cleaning...she sets the standard for cleaning cylinder heads

[Jazzer]

The machine shop did a beautiful job of cleaning the head as well as a valve job ($314), in 2 days to boot. As I clean up the block in preparation for assembly, I'm curious: I have read in this forum and others that scotch brite pads should not be used. Yet in multiple online resources the most common method of cleaning the surface is a green scotch bride pad, along with brake cleaner, wd40, oven cleaner, etc., etc. Should we not use the green pad, or are we referring to a different pad?