No compression on 1 - burnt valve? Topic is solved

[songzunhuang]

So as the parts roll in for my repair, I thought I would catalog them and also ask a few people what some of the seals are for! There's one package (red arrow) that I can't figure out. I looked for the catalog number of the Victor Rienz site, but I just can't locate it. There are 5 sets of each, which leads me to believe it's injector or ignition related, but it matches nothing on my car.

Lots of bits to replace.

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You can see the new Volvo hydraulic lifters in the lower right in the picture above. They came individually packaged in a nice cylindrical container with oil in them. However, some of the lids came off in shipment and I have a very oily box. Also you can see the 2 new exhaust valves I bought, even though I only have 1 burnt valve. Not sure if I should replace them in pairs or if it matters at all.

During all this, II noticed a tiny bit of play in my water pump. Well, I figured that I've gone this far, I may has well replace that too. Off to order more stuff online. That meant the belts had to come off, etc., etc.

What do you guys use to get the old gasket off? The green ones for the water pump and related parts were really difficult. I even carefully used a razor at times because no plastic thing was doing anything useful.

One thing that was a major headache was a bolt for the thermostat housing. I basically couldn't make it budge and I ended up doing this.

Cutting off the bolt.

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So I had to order a new bolt with a 43mm hex head as well as a new thermostat housing. I just couldn't get that darn screw out. I figured I may as well get a new one instead of messing with drilling it out and re-tapping it.

My exhaust studs came out of the cylinder head as I was disassembling. When I was removing the nuts afterwards, I messed up the threads on a few studs because I had to use a vise grip. So those were ordered too. I understand that the studs need to be on the head to reinstall or it'll be really tricky to get the exhaust manifold gaskets in. I'm just playing it all by ear. All in all, I must have spent another 5 hours just cleaning off stuff and prepping (also factoring in the water pump removal and cleaning. Here's what I had at the end of that.

Ready for new head.

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So this week I take the head into the machine shop. I look forward to what I hope to get back.

[songzunhuang]

Well done! It is very satisfying to remove the head and clearly identify the problem. Think of the satisfaction you will feel when you restart the engine you repaired.
volvolugnut

Yea, it'll be great to get it going again. It was satisfying to know that my prognosis was correct. Also, getting the head off wasn't as bad as I was expecting. The main annoyance is when you discover other stuff that needs replacing. Scope creep!

[songzunhuang]

Get new exhaust studs and bolts and have the shop take them out for you.
Can you add more to the stripped intake valve hole screw? Not sure I understand where you are

I ordered 3 new studs since I damaged the threads on them when I cranked off the nuts. I also managed to lose one of the 4mm exhaust washers. My parts orders just keep expanding!

It's weird about the intake manifold screw. Off the car, I was able to insert the screw just fine and it seemed to hold. Visually the hole and threads doesn't look too bad. Not sure why I couldn't get purchase when it was on the car. I'll ask the machine shop to clean up what they can, but there may not be much. A slightly longer bolt may be good enough.

[songzunhuang]

That’s a lot of work. I did the exact thing in my trunk with parts in order!

What caused this? Too lean?
Is this a significant comment here?

Then there's a stripped screw hole in one of the intake valve holes.

I am not sure what the cause was. Most seem to attribute it to a valve seal issue or a lean condition. My issue was on 1, which isn't the cylinder that had the problem with the intake screw being loose. That screw was between 4 & 5.

I'm not really sure how to conclusively tell about the valve seal. I guess the top of the piston was a bit oily, but that must have been something to do with disassembly as any oil must get burned off in the temperatures during normal running. Maybe the machine shop guy can give some observations when he disassembles for cleaning. We shall see.

[abscate]

It is a lot easier to put that water pipe back in with the exhaust manifold removed. It is also worth removing it to check for cracks that are starting, especially on the RN turbo one.

To get the thermostat bolt off apply heat at the base of the bolt, on the lower side of the thermostat.

30-60 seconds of propane heat will bust up that thread corrosion and it will come out, replace with new of course.

[songzunhuang]

I finally got my remanufactured heads back from the machine shop. I knew what was coming, but the stark difference still startles me.
I'll just let the pictures do the talking. I can't wait until I get to put this on next week.

Before and after, the whole head.

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As you can see, amazing the difference.

Here's a closeup on the exhaust valves on #1. I purchased new valves from FCP Euro. They don't look quite like the stock Volvo valves, but I guess I'll never see these again after installation. As you can see in the "Before" picture, the bottom left exhaust valve had a chunk gone.

New Exhaust valves on #1

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Finally, here' how the other side looks. The valve cover still has some gasket residue, but I think that'll be much easier to get off now that the major stuff is gone.

The topside of the head.

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All in all, this work cost me $505.

Resurfacing was $75.
Valve job was $350.
Pressure test was $75.
Then there was a $5 Hazardous waste fee. I don't see an entry for cleaning. I guess they just wrapped it all into one of the other steps. The machine shop that did my head was the same as the one who did my BMW many years back. They do a really great job.

It'll be several days before I have time to tend to this, but I'm excited at the prospect of getting the red brick back on the road.

[hausmeister]

Lots of work.
I would also check the injectors, we don't know if they are the reason for it, but it won't hurt and is sensible imo. Maybe someone offers cleaning, or you can get refurbished ones...
You an also try to clean them by yourself, build something to actuate the injector and spry carb/intake cleaner through it... I tried it on my old ones after I bought refurbished ones. The old ones did not even have a spry pattern, more like a water hose.

This is one way, I used some hose and hoseclamps and glued an adapter together, also works.

[volvolugnut]

A 9 volt electronics battery will fire most injectors for these tests. You have to make and break the connections since the injector uses a pulse to fire.
volvolugnut

[BlackBart]

So are you guys saying a leaking valve seal is letting oil into the combustion chamber where it will burn hotter than the fuel mixture? Or that the oil cooks on the way down a hot exhaust valve and makes deposits on the lip of the valve so that it doesn't shut fully and burns a spot?

I can see where a clogged injector leans out that cylinder and burns a valve.

[abscate]

There are some pictures in the other burned valve thread where you can see how hot gases blew a gouge in the valve