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2002 H6 - no compression!

23K views 59 replies 11 participants last post by  Novablue 
#1 ·
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?
 
#36 ·
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!!!!

 
#37 ·
Phew! Way to go, and good luck! I'm sure there will be a clear issue once you get in there.
 
#38 ·
"That's a good price! Almost cheaper than having a dealer change your spark plugs....."

:29: Sometimes true. Of course the engine is in Jersey, so delivery may take a little extra time. I think the trucking is almost caught back up.

It's still seems like a possibility that the lifters stuck when it was shut down and then the damage was done on start up. Could also be a lot of carbon just causing poor seating of the valves.
 
#39 ·
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!?!?!?
 
#42 · (Edited)
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.


What do you guys think? Did I figure it out, or did I take apart my wife's car for nothing!?!?!?
No you didn't.

Take the heads to a shop that specializes in cleaning and machining. Not sure about the block because you didn't show picts of that.

This engine shows poor maintenance over it's life possibly cheap fuel and lack of cleaning. Once it's cleaned up I think you'll be happy assuming nothing is bent which is why you should have it checked out. It's possible to not "see" a bent valve. Get estimates and see if you want to go new or clean/repair.

Carbon build up causing no compression is possible in situations like this.

I agree with Cardoc. Other manufacture engines would not be worth repairing at this point because there would be more damage.

As to using sea foam, it works if you use it like Cardoc says, but I have had good luck by trying to make sure I always use premium fuel. I've put 100k on 3 engines now and all of them look like new with those miles. I have yet to use sea foam but I do use good synthetic oil and Chevron or Texaco fuel. "An ounce of prevention is worth a pound of cure."
 
#40 ·
No, you didn't. It's easier to do this work with the engine out. Less hassle and tension.

While you have it apart for the valve job, you may want to consider the condition of the lifters, cams, new bearings is a given and whether you want to do that water pump/chain assembly. At minimum you should replace the guides and tensioners.

This is a good example of why you should use a cleaner in the fuel, intake and quality oils. And don't go a long time between oil changes. If this wasn't a Subaru, it would be trashed.
 
#41 ·
. . . This is a good example of why you should use a cleaner in the fuel, intake and quality oils. And don't go a long time between oil changes. If this wasn't a Subaru, it would be trashed.
FFR5445: What is the record for the car in relation to cardoc's suggestions? (Any reason for the build up?) Also, was the car bought new, or second hand with an uncertain past?
 
#43 ·
A whole can of Sea Foam in the gas tank twice a year.

Up to two times a year, run the Sea Foam through a vacuum port on the intake with the engine running to dissolve the oil deposits created by the crankcase venting system. This would depend on he mileage you drive. Round it to every 15k.

Oil breaks down and creates carbon deposits within the engine. That's what that crusty brown caking is. When you go a lot of miles between oil changes or let it run low this occurs quicker. The carbon is baking to everything it contacts.

Higher quality fuel keeps the fuel system cleaner as well as improve the overall performance of the engine.

If you look at the photo of the full head you will see the oil build up on the edge of the combustion chamber on the bottoms side under the exhaust valves. This may be an indication of ring wear or valve seal wear allowing oil to seep into the chamber after shut down and settle on the base of the chamber. And that's a lot of build up. It could have been from more recent or over a period of time. I think more recent just because of its coloring. It's not burned up completely.
 
#45 ·
The PCV system allows the engine to pull gases out of the crankcase that are created normally from heat and pressure. At the same time it sucks oil particulates. The particulates adhere to the surfaces of the induction system and over time will thicken. This changes the flow of air. It adheres to the intake valves as well as the oil is pulled through to the combustion chamber. This is that black film you often see on the trottle body. When crankcase pressures are high during high engine rpm, the effect is greater.

Abnormally high crankcase pressure can be due to small things like using heavy oils to ring blowby.

On this engine it appears the valve seals are bad. When the engine is stopped, valves remain open. The oil deposit at the base of the head indicates the oil was draining into the head every time the engine was stopped and the next time it was started it probably smoked a bit until it burned off the loose oil in the chamber. Judging from the photo it looks to have been going on a while. It just got to the point the carbon and sludge lodged the valves open.

It is possible that a clogged PCV valve could accelerate internal leaks. The pressure will find a way out. Given the mileage of his engine, the seals were most likely worn.
 
#47 ·
PCV checks out good. Valve seals have been bad for the past 2 years and 40k miles so this engine failure doesn't come as a surprise. It has 160k on it now.

I'm debating whether or not to just throw a JDM engine in it. Aside from the hours and hours of cleaning, these timing covers are ridiculous and must have over 20 o-rings and 100 bolts. There are a lot of potential leak points.

I'm going to call some engine machine shops tomorrow for a few quotes on a valve job. Do I leave the cams on so they can do the valve adjustment too? What should I expect to pay?

Head gasket set seems to run about $250, plus water pump $60, valve seals $35. Don't think I would touch much else. I know people have problems with the chain guides but these are in perfect shape.
 
#49 ·
Not necessarily. If that deposit was liquid, it would have a smaller mass, but the large amount of deposit at the base indicates it got worse quick. I'd bet the engine was close to a quart low when he pulled it.

As far as the machine shop, I don't know about up where you are, but the shops down here will do the labor, the owner has to bring the parts. They can't get them through their suppliers. Weigh the cost. You also have to have the Fuji Bond or equivalent and a lot of it. It can add up in cost. You can't use regular RTV and not expect a leak. If it goes to a shop, leave the cams on.

If you go with replacement, you could recoup some cost selling it for rebuild or aluminum scrap.
 
#51 ·
That is interesting. Never had it happen.

It's always a what if. In this case on this thread he had tried sever times to start it, had the plugs out, turned it over several times. This should have blown it out. Given the time lapse between shop 1 and 2 in the above referenced post, the fuel most likely evaporated while sitting via the open valves. Along with the tech running into it before.
 
#52 ·
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.
 
#53 ·
dude that's crazy. nice job figuring it out.

that being said - i've actually seen a lot of Subaru EJ heads that leak some small amount. when filled with fluid, they leak some out, even on engines that ran fine.....so some bit of "hanging" happens, but at the kind of RPM's, insanely short durations, and pressures they have I guess it's not noticeable until a certain threshhold...which i suppose you reached.

very interesting, thanks for sharing.
 
#54 ·
head jobs get expensive quick. you can generally get a price, it's semi-standard, enough that you can get an estimate online or over the phone. shops i've used always have a "per valve" price for lapping....24 valves times $10 each is $240 for instance.

lapping valves, new valve stem seals, and adjusting the valves.

you can resurface the heads yourself if you want. it's actually really easy, fantastic write up on USMB about it. search "apocalyptic head resurface" or something and it comes up. of course that's generally not that expensive anyway. i do it because the closest shops to me are really far away and inconvenient. now that i've done a few it's unbelievably simple. if you pulled a motor you can resurface your heads in a couple minutes easily.

$50 clean, $250 for lapping valves, valve stem seals, resurface, they'll want to pressure test but i'd decline that myself.....pushing $500 in machine shop work unless you have unusually cheap prices.
 
#55 ·
The root of the problem was the bad the valve seals. There were bad since 125k and created the oil contamination and carbon buildup that you see here. It never ran low on oil and was never overheated. It certainly could have gotten worse at the end. It's not my car and so I rarely drive it. I can guarantee if it did get worse and mass quantities of blue (yes it has always been blue) smoke are pouring out the exhaust, my wife never would have noticed it.

The machine shop wanted $505 to do the valve job. That includes a valve adjustment and resurfacing. He said he does subaru heads all the time although mostly the 4 cylinder variety.

So I decided to go with the JDM engine. I was really worried after googling JDM Engine Depot Reviews. There are some bad experiences out there. But it is a used engine so there has to be some. The sales guy seemed nice enough. He took pictures of the actual engine I was going to buy and sent me a video of them doing a compression test on it. I got the engine yesterday. It seems ok. Only some minor seepage at the bottom of the timing cover. Valve covers are nice and clean. Lots of aluminum surface corrosion but that seems completely normal for its age. My biggest disappointment so far is the engine wire harness was all cut up. Not sure if they need to do that in Japan for some law because it was cut in several places. It's Friday evening, I don't have intake gaskets or fuel injector o-rings and won't be able to get them for several days so I'm trying like heck to swap the harness without pulling the intake manifold. It's not easy but I think I'm going to get it!
 
#56 ·
This same thing has happened to my mother's 2001 LL Bean H6, twice. Each time the engine was suspect, timing chain was checked, etc. interestingly, each time the oil was low, it was topped up, the engine was cranked for 30 seconds or so, then it came back to life. Somehow (don't ask me how) when the oil is low,and of the car is parked for a while, the hydraulic lifters collapse and the valves cease to function.
 
#58 ·
Another issue with the JDM engine (besides the engine harness being hacked to bits) was a dented oil pan; it was shipped resting on the pan. It probably would have worked but I decided to play it safe and swap oil pans.

Got it all back together. The torque converter bolts are tricky, but everything else is pretty straightforward. Only 1 trip to the parts store for exhaust bolts and some RTV. Filled it with fresh fluids and she fired right up. No leaks, no drive-ability issues so far. That 6 cylinder is a smooth engine.

Thanks to all that helped me. I'm off to relax with a cold beer.
 
#59 ·
another issue with the jdm engine (besides the engine harness being hacked to bits) was a dented oil pan; it was shipped resting on the pan. It probably would have worked but i decided to play it safe and swap oil pans.

Got it all back together. The torque converter bolts are tricky, but everything else is pretty straightforward. Only 1 trip to the parts store for exhaust bolts and some rtv. Filled it with fresh fluids and she fired right up. No leaks, no drive-ability issues so far. That 6 cylinder is a smooth engine.

Thanks to all that helped me. I'm off to relax with a cold beer.
road trip!!!!!
 
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