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Old 08-06-2002, 02:37 PM   #1
Daveish
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Default Help me guess what happened to my broken engine!! (long)

Hi everybody. I'm trying to figure out how I broke the engine in my 2.5RS - if anyone could impart some wisdom on me I'd really appreciate it.


A little background info: I installed some cobb street cams, did the valve adjustment, and followed the break-in procedure for the cams (2k rpm for 15 minutes). Took the car for a test drive, and the car ran fine, except for the valves being a little loud (a poor valve adjustment, on my part). The power I expected to gain wasn't quite there, either.

Another 25 minutes later, as I was driving home, the exhaust started to get louder and louder, as well as the valves. The car slowly started to lose power, until the car stalled. It smelled like the car was running rich, as well...

I had the car towed at this point, figuring it would be safest before I could readjust the exhaust valves (which is what I figured the problem was).


Now: the dealer I took it to says the right camshaft broke near the front of the engine (where it attaches to the cam sprocket). The cam sprocket flew off and shattered my timing belt cover, and broke my timing belt. Obviously, this resulted in bent valves on the right side. The dealer guessed that I had overtightened the bolt holding on the right cam sprocket, causing it to seize, but I find that unlikely, since I used a torque wrench in the reinstallation of everything from the camshaft cap to the timing belt cover. I'm also 97% certain our marks on the timing belt lined up with the marks we made on the cam sprockets, so I don't think the two cams were out of sync.


My question(s):
- if this happened while I was driving it, wouldn't I have heard it, much less felt it, when the cam gear flew off and broke the cam?
- could it have been a bad camshaft?
- Any other ideas, that could cause my camshaft to break?
- Why me?!?
- The flow test on the good side (left/driver) showed an leakage @ 8% rate -- is it safe to say that the 8% loss is from rings/seals, and the left side is probably okay?
- Could this possibly be a warranty issue?


Hope someone can help me think of some answers... any help is really appreciated.

Dave
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Old 08-06-2002, 06:26 PM   #2
munkis
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Default

a warranty issue how?..

SOA is sure as hell not gonna warranty your engine with aftermarket cams

sicne I didnt see the install or how it was done, its really hard to place blame here..could it have been a bad camshaft...yes..could it have been in install mishap...yes.

Sorry about the engine...but it will be really hard to determine the exact cause...

This scares me too
Quote:
I'm also 97% certain our marks on the timing belt lined up with the marks we made on the cam sprockets, so I don't think the two cams were out of sync.
there is no room for error in this game. you should have put a new timing belt while you where int here, the new belt comes marked as to where it is suppose to line up with the marks on the front cover...did you line up the crank gear with the notch on the block and the notch on the gear before you took the belt off? did the driver side cam spin alot during the install?

Jay McDade
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Old 08-06-2002, 06:45 PM   #3
Daveish
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Yes, I figured i was SOL as far as warranty goes, but I thought I'd get people's opinion on the matter. I'm fully prepared to pay for the repair, but the only thing I see as strange is the fact that I didn't experience anything as violent as a cam gear flying through my timing belt cover when I was in the car. That's why I say "warranty". Which is why, if there is some possibility that the camshaft was not broken at the time I had the car towed, I don't see myself as responsible for (all) the damage that occured.

Also, the only reason I say 97% sure on the timing marks is because I did not visually inspect all three gears of importance myself. But, my friend who was helping with the install did, and I trust his eye as much as I trust my own.

Yes, all three gears were lined up with their appropriate marks on the engine, in the position they were in when the belt was removed.
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Old 08-18-2002, 09:16 PM   #4
ImportInvasion
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I donít think your valves would have "obviously" been bent because of a timing belt breaking. If your engine is SOHC I donít think you would be in any danger of bending your valves. Is it even possible for the valves two touch each other with only one cam on each side? The 2001 is SOHC right? With the DOHC you could damage the valves, but if the timing belt breaks, maybe its just me, but i would think the two camshafts on each side would slow down at an equal rate and not allow the valves to hit each other. Am i wrong?

NOah

Quote:
Now: the dealer I took it to says the right camshaft broke near the front of the engine (where it attaches to the cam sprocket). The cam sprocket flew off and shattered my timing belt cover, and broke my timing belt. Obviously, this resulted in bent valves on the right side...
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Old 08-18-2002, 10:42 PM   #5
Fred Zaplitny
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Quote:
Originally posted by (-ImportInvasion-)
I donít think your valves would have "obviously" been bent because of a timing belt breaking. If your engine is SOHC I donít think you would be in any danger of bending your valves. Is it even possible for the valves two touch each other with only one cam on each side? The 2001 is SOHC right? With the DOHC you could damage the valves, but if the timing belt breaks, maybe its just me, but i would think the two camshafts on each side would slow down at an equal rate and not allow the valves to hit each other. Am i wrong?

NOah

Quote:
Now: the dealer I took it to says the right camshaft broke near the front of the engine (where it attaches to the cam sprocket). The cam sprocket flew off and shattered my timing belt cover, and broke my timing belt. Obviously, this resulted in bent valves on the right side...
Bent valves happen when the piston hits the valves, not the valves hitting each other.
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Old 08-19-2002, 01:12 AM   #6
Daveish
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Yup. but without a timing belt to control the cam the valves will be open off-time with the pistons letting them collide. I left out that detail.
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Old 08-19-2002, 05:28 AM   #7
HndaTch627
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Default

did you properly pre-lube the cams???for a cam to sieze it would need to be starved of oil...now the only way this could have happened is if you clogged the passage with RTV when reinstalling the girdle or you forgot to put oil back in the car and were re-ciculating the 1/2 that was left in the motor...but that's all ic an think of/

jeremy

p.S.: i'd like to see a cam snap by over-torquing the cam gear
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Old 08-19-2002, 08:21 AM   #8
ImportInvasion
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I have been told by a number of people that all subaru engines are non-interference engines, meaning that the valves can never hit the pistons. However on the DOHC the valves can hit themselves. Good luck too you, by the way.
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Old 08-19-2002, 11:11 AM   #9
inpreza kid
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actually i think ALL phase 2 ej25's are interface.
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Old 08-19-2002, 01:31 PM   #10
HndaTch627
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Default

Quote:
Originally posted by (-ImportInvasion-)
I have been told by a number of people that all subaru engines are non-interference engines, meaning that the valves can never hit the pistons. However on the DOHC the valves can hit themselves. Good luck too you, by the way.
BUHAHAHAHAHAAHAHAHAHA!!! yeah so was i....and believe me they are INTERFEREANCE motors.

jeremy
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Old 04-14-2004, 12:01 AM   #11
Hugh Mayo
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I had a similar problem occur on my 1998 Legacy Outback (2.5L DOHC) except it is 100% stock. The engine started to squeel and then died. Turned out the upper cam on the drivers side seized up. They have to replace the head, camshaft, cam gears, timing belt cover, etc. (big bucks). The engine had 130,000 Kms but was well maintained, having regular service, tuneups, etc. The timing belt had been replaced at 128,000 Kms. I have been told that the engine must have ran without oil at some time but I do my own oil changes and know this is not the case. There is a thread in the Forester forum describing a similar situation and I have read this elsewhere. I have not heard of any explanation why this occurs and Subaru sure isn't admiting to a problem. Curious!!!!
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Old 04-14-2004, 12:04 AM   #12
ttboy19
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bummer man, good luck with your situation.
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Old 04-14-2004, 10:05 AM   #13
Warp3
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Quote:
Originally posted by (-ImportInvasion-)
I have been told by a number of people that all subaru engines are non-interference engines, meaning that the valves can never hit the pistons.
This was true on the older EA-engines found in the Loyale/XT/1600/1800 series (and some of the early EJ-engines, IIRC) but pretty much all the newer EJ-engines are interference engines now.

Shane
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