2002 H6 - no compression!

I have spark plugs removed from cyl 3, 4, and 2. I performed the cylinder leak down test on the three cylinders with very poor results. 80% leak is standard when I know the valves are be open, when the valves are supposed to close, the needle may jump to 75% leak. Its hard to tell, but I think the air is coming out the exhaust.

I triple checked my crank/cam timing. Its spot on. Triangles all point straight up. It looks just like picture 95 on page 29 of this guide.

What are the chances it jumped timing, bent the exhaust valves, then jumped back in perfect timing? I'm out of ideas. What do I do next? If I pull a valve cover will I be able to tell if a valve is not closing all the way?

Here is a picture in effort to share my misery.

Got me brainstorming on this one. 4 things necessary for and engine to operate: Fuel, Air, Fire and Compression. So a review.

You are sure the compression tester is working properly, so no compression on any cylinders. None.

You have spark. Spark means the crank turns otherwise you wouldn't have a signal for TDC to the computer. This is good. The crank is in one piece.

You have fuel. Pump works.

Do you smell raw fuel when the engine is turned over? Yes means the injectors are firing. No means the injectors are not firing. The computer uses the CMP, cam sensor, to fire the injectors.

The gears are rotating? All of them? Are the cams turning with the gears? I know it seems like an dumb question, but I've seen some weird things occur in an engine in the going on 26 years I've been building/repairing.

Air is heard in the exhaust during the leakdown test. Exhaust valves are open. Possibilities are seized lifters holding the valves open, which would also mean bent valves, maybe damaged pistons if the valves are full open. Depends on the force of the impact. Given the amount of sludge/carbon on the front of the engine from the photo, it is a possibility. It would be a fluke that enough lifters seized on shut down to cause a total loss of compression, but nothing is really impossible. It will only need 6 valves unseated to cause all cylinders to lose compression. Lifters could have been seized on start up and that's where the damage occurred. The lifters don't have to be seized now, just may have been a factor when the failure occurred. They don't even have to be seized at the same degree. The head covers will have to be removed to check the valves for open/closed at proper position in relation to the cams.

And you are sure of the cam positions when the leak down was tested on all the cylinders?

I know it may look like a chore, but you are most of the way there. Remove the engine. It can be done in less than an hour's time from where you are now and will make it easier to work with in tracking down the issue. If you rebuild or replace, you will be removing it anyway. And its looking like that's where you are headed.

A full rebuild on one of these can run $3k, parts and machine shop to do it completely. JDM Engine Depot is showing one EZ30D available for $1k. The other option is a salvage motor unless LockMedic has one lying around he can let loose.

Thank you to everybody contributing to the conversation. I really appreciate your experience and ideas.

A quick review
Fuel - I don't have a pressure tester so I did a volume check. It's pumping plenty of fuel. The spark plugs were also wet with fuel. I'm certain.
Spark - I have a spark tester and verified spark on cyl #3 while my wife cranked the engine over.
Compression - Zero confirmed by compression test on cylinder 3 and 4. Major compression leaks confirmed by cyl leak down test on cylinder 1,2,3,4. I'm certain the cam positions were good. I even rotated the crank by hand 720� deg while doing the test to make sure. The needle doesn't go better than 75% on any. When the valves should be closed, I feel air coming from the tailpipe. I haven't checked cylinder 5 and 6. They are hard to get at, and if the other 4 don't work, what is the point?

Some history on the car.
My parents bought it new and had very little problems with it. The oil was changed every 5k miles and they did primarily highway driving. I bought it 2.5 years ago at 108k miles and continued with the 5k oil change interval. After every oil change, I notice the sound of lifters loudly clanging for the first few seconds until oil pressure builds. According to my Dad, it did that after his oil changes from the get-go. Lately, I would pull the fuel pump fuse and crank the engine until the oil light goes off to prime it after oil changes. About 2 years ago, I noticed a small puff of black smoke from the tailpipe at cold start up in the morning. The oil puffs have grown bigger lately but always at cold start up and they never last. After a few seconds the engine runs normal. It burns about a quart of oil every 4k miles.

Interesting enough, this failure happened at cold start up.

I got the valve cover and off. 2 of the bottom screws were very loose and it was leaking oil from there. Was hoping to see a gap between the cam and lifter when off the lobe but that is not the case. At least now I can see the camshaft working. It verifies my same results. Working on cylinder #1, I can now see exactly when the valves should be closed. When #1 is at TDC and all the timing marks align, I send air into the cylinder and the air just pours out the exhaust. I have the O2 sensor removed and the tailpipe plugged with rags and it pours out the O2 sensor hole. My exhaust valves are not closing. I have no other choice but to remove the cylinder head for further inspection.

I'm going to pick up an engine hoist tonight and I took the day off work tomorrow. Try to stop me if you think I'm crazy, but please have a good logical reason. I know this is a strange one.

I found a used engine at nearby salvage yard but anything reasonably priced has over 100k miles on it. Tell me about these JDM engines if anybody has any personal experience. I used one about 12 years ago on a mitsubishi eclipse. It came nice and clean but I remember I had to swap the intake and a ton of other parts due to the difference in emission requirements. Maybe it's not like that anymore? Shipping cost it probably big too.

I got the engine out. Took me all day and I'm exhausted. Had trouble getting to the lower bell-housing bolts but finally got it. When I separated it from the trans, the torque converter came with it a bit and some fluid leaked out. I just pushed it back in the transmission. Do you think I damaged anything in there? Is there seal behind the torque converter I should replace?

I was hoping to get a cylinder head off today but its going to have to wait. I still need to remove the intake, timing chain, then another 50 or so timing cover bolts.

What am I going to see when I remove the cylinder head? Bent valve, burned seat, hole in valve? My biggest fear is it is perfectly normal and I'm completely crazy!!!!

The cylinder head is off. No bent valves, no holes anywhere. At first I was all upset because nothing was obvious and this is just so strange. But then I took a closer look. LOTS of carbon build up on cylinder and around valve and valve seat.




This appears to be the carbon build up that was holding the exhaust valve open!!! Really??? Will that hold the valve open!?!?



I should also mention that when I drove it the night before, I didn't go far, just moved it in the garage. Then when started the next day, it got another dose of oil and carbon from the bad valve seals. So I guess that was enough???

What do you guys think? Did I figure it out, or did I take apart my wife's car for nothing!?!?!?