Subaru Outback Forums banner

1 - 20 of 60 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #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?
 

·
Registered
Joined
·
16,967 Posts
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
 

·
Registered
Joined
·
13 Posts
Discussion Starter #4
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.
 

·
Registered
Joined
·
16,967 Posts
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.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #10
he should see the serpentine belt moving - and maybe hear valve-crunch noises but, yeah - worth mentioning.
Yup I see the belt moving. And it has spark which must be triggered from the crank sensor. Anybody know of an easy way to check if the cams are turning without taking the timing cover off? Maybe my scanner can read the cam sensor, but I doubt it, I only have a basic one.
 

·
Registered
Joined
·
16,967 Posts
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.
 

·
Registered
Joined
·
2,926 Posts
Ouch... Not looking good.

My bad, right with spark the crank sensor must be getting triggered...
 

·
Registered
Joined
·
13 Posts
Discussion Starter #13
Well I got the timing cover off. I was expecting to see carnage but it all looks good. Timing marks all align where they should be. So now I'm really confused.

Got to thinking I need to do a cylinder leak down test (should have done that yesterday). So I dug out my tester put the timing marks all up and plugged it into the the forward-most drivers side cylinder. Can somebody confirm for me that this is indeed the #1 cylinder? I know the cylinder is at the top of its travel. I get 80% leak and it is coming out of the tailpipe.

Anybody have a diagram of firing order and cylinder identification?
 

·
Registered
Joined
·
12,308 Posts
Drivers seat
5 6
3 4
1 2
Front of car

1 is front passengers side, 2 is front drivers side.
1, 3, 5 on passengers side front to back. 2, 4, 6 drivers side front to back.
 

·
Registered
Joined
·
12,308 Posts
This is very bizarre, will be following along hopefully.

Any repair history at all?

Anybody know of an easy way to check if the cams are turning without taking the timing cover off? Maybe my scanner can read the cam sensor, but I doubt it, I only have a basic one.
bump the starter just for a second. it'll get oily but some proper cardboard will take care of that. i've bumped, and even ran for a second, an engine with exposed valve train, it's just a little messy. It's just like a timing belt except some of the oil won't get captured so to speak...

although you should just be able to turn the crank by hand and see all the cams moving.
 

·
Registered
Joined
·
2,342 Posts
Zero compression usually means one of a few things namely:

Valve issue

Piston issue

If when performing a leak down test the compression rises significantly it is a piston issue. If it stays the same it is a valve issue. I don't know your engine specs but 5-10% difference can be normal, more than that is bad.

If you have oil coming out the tailpipe, you likely did the leak down test incorrectly or your engine is toast. Rotten eggs is a tell tale smell of a blown engine btw. You only need a small amount of oil to perform the test. If you are confident you did the test correctly you may have a broken crankshaft. It is really rare to have zero compression in more than one cylinder on both sides of the engine and have it be a piston issue. What you are describing sounds like the valves are not sealing correctly.

Of Course if you have a broken crank, nothing would line up right and the valves would be open when you do the tests. Lets hope it's something simple. It sounds bad at the moment. If a pulley went bad or the chain/belt was loose or broken you might experience what you are describing.

If it were me:
Perform a compression test on all cylinders. If all cylinders are zero it is likely a valve or crank issue.
A) Compression is zero on all cylinders, most likely a valve issue: a) double verify timing belt is correct b) Verify that the crank is in the proper alignment which is more difficult.
B) Compression is good on other cylinders but not the two: Suspect bent valves on bad cylinders

From here we could check more but I'd need to know the results of that to proceed.

My first guess without seeing it is the chain/belt/pulley broke.

Edit: Also make sure you are using the correct threads for your compression tester. Line them up with the spark plugs to be sure.
 

·
Registered
Joined
·
16,967 Posts
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 !)
 

·
Registered
Joined
·
2,342 Posts
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:
 

·
Registered
Joined
·
13 Posts
Discussion Starter #20
Thanks for the replies. This is really rackin my brain.

I need more data. Now that I have the correct cylinder ID (thanks grossgary) and firing order, I'm going to do a cylinder leak test on at least the accessible cylinders tonight. Hopefully I will get somewhere. To get at all 6 cylinders I would need to loosen some engine mounts and jack up the engine. After all the parts I have out of this thing, that wouldn't be a huge deal, but the results from a few cylinders should tell me something.

I notice the spark plug threads are really long (~1.5") on this H6 but my compression tester only has threads that are much shorter (~.25") long so maybe all that extra air would affect my compression tester???
 
1 - 20 of 60 Posts
About this Discussion
59 Replies
11 Participants
Novablue
Subaru Outback Forums
Welcome to the Subaru Outback Owners Forum, we have tons of information about your Subaru Outback, from a Subaru Outback Wiki to customer reviews.
Full Forum Listing
Top