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2002 H6 - no compression!

21928 Views 59 Replies 11 Participants Last post by  Novablue
Hey guys. I'm hoping you can help me out. I have a 2002 LL Bean with the H6 engine. Went to start it this morning and it just cranked over fast, no start. If you've ever heard an engine trying to start with a broken timing belt, that is what it sounds like. I verified fuel, then spark and both are good. Plugged in my compression tester to the RH middle cylinder and I get zero compression. I don't even want to bother checking the other cylinders because they are such a PITA to get to and I'm fairly certain they all have zero compression also. So what the heck happened here?!? It has about 160k on it and car was running great last night.

My next thought is to pull the timing cover and start checking it out. I'm guessing I have a broken timing chain or stripped timing cog.

Does anyone know where I can find a guide on pulling the cover? I assume I just need to pull the radiator and then I can get at everything?
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do you have a check engine light on? I'd expect some kinda crank angle/cam angle code at least.

there are 4 different length bolts I think holding the cover on. I've heard some people start by drawing the cover's outline on a piece of cardboard so they can push the bolts through at the representative locations.

some people say the valves need adjusting around 200K so, may as well investigate that too before putting it all back together.

tough news
I did verify zero compression on the LH middle cylinder also. And just for the heck of it I checked my compression gauge is working correctly on another car.

I drove it the night before without any problems. The check engine light was not on at the time but it doesn't hurt to check. I'll hook up the scanner tonight before I tear into the cover. Thanks for the tip!

This is an interference engine so if it is a broken timing chain, my valves are most likely bent and I'll be shopping for a used engine. The car is just too nice to scrap at this point.
duh, yeah, I forgot the valves might be trashed.

bad luck, doesn't seem to be a common failure , though not impossible, for the H6es in general. I have seen pics of broken plastic chain guides and places where chains have chewed through aluminum bosses etc.

be interesting to see where the problem was. With zero psi on both sides, seems like a crank sprocket issue but certainly one chain could have created enough debris or interference to knock the other one off I guess.
I wonder if the starter is engaging?
he should see the serpentine belt moving - and maybe hear valve-crunch noises but, yeah - worth mentioning.
maybe try holding a strip of paper at the tailpipe. If it is 'sucked in' diruing portions of the rotation while someone cranks the engine, it's because valves are open when they shouldn't be.
if you have any doubt about the compressions tests, check for the cracked cap/blown o-ring on the fuel pump.

(I'd like to see a picture of how you do a compression test on this engine, especially cyl #6 !)
What does the fuel pump have to do with cylinder compression? :confused:
nothing, just suggesting the possibility the low/no compression is an incorrect reading. (with apologies to the OP)

I'm with gg, this is becoming bizarre.
I have seen exactly zero inside covers, but I think cardoc's observation about varnish/gum w'ever is interesting - seems quite dark or thick to me.

Is there something that could have been aspirated that would clog valves? intake parts or filter material?

was there some kinda oil pressure loss causing valves to seize?

has the car ever taken a hit to the oil pan?
how many total miles now? Some folks say the valves need adjustment at around 200K - though I can't see that being a primary issue here.

any carbon build-up on the plugs?

oil use seems too good to blame a PCV valve for gumming things up.

kinda feels like low oil pressure/ or oil that is foamy going to the heads but, all I got are wild ideas.
After every oil change, I notice the sound of lifters loudly clanging for the first few seconds until oil pressure builds.
I never get this on my 03, but i do partly pre-fill the filter with new oil. (can't fill it completely, but maybe by 1/3 or so of it's volume)
this thread is crazy.

is there someway the PCV system could have led to this?

if that color was on the plugs - what would it indicate?
seems like oil usage would have been much worse than 1qt/4K miles . Does poor oiling lead to this? overheating?
OK - I was researching for another post, ran across the following;

pay attention to where the compression was measured.
I admit, ffr may not have had 'cylinder wash-down' or w'ever it's called - but it seems possible, particularly with some of his other 'black smoke' issues.

But, he didn't mention seeing/smelling fuel soaked plugs and, as you say, seems like there was opportunity for evaporation.
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