Aloha from Hawaii,

 

The passenger side plastic cam sprocket on my 2000 EJ253 Forester just disintegrated and broke through the cover. As this is an interference engine and the timing belt malfunctioned, what are the chances that I do not have other engine damage besides replacing the sprocket and the timing belt.

 

Be honest, I can handle the truth.

Edited June 2, 201213 yr by 2002ForesterGuy

there is a chance, but only a slim one that there is no other damage.

the good news is that you probably only have bent valves on one head, maybe.

 

you will likely find that the tooth idler sprocket is also bad. this is usually the one that fails and then causes the passenger side sprocket to collapse. not a big deal since you will replace ALL the idler sprockets AS WELL AS the tensioner and the water pump. this is the only way you can know for sure that you are good for 100k miles. you certainly don't want another idler to fail in 10k miles. and you can't really expect these idler bearing to last 200k+ miles. and certainly not 300k. (good parts to be had on ebay from ''theimportexperts''.)

 

so depending on where you take it and what the labor rate is you are looking at $1500 - 2500$, maybe more, give or take, depending on labor. (what does a six pack of bud cost where you are ?)

 

engine comes out

heads come off

both heads go to machine shop to be checked

''mill'' both heads if needed for flatness.

 

if this is all you need this is just a head gasket job.

 

replace bent valves, probably 4 - 8, maybe more.

reassemble the engine and re-install.

 

if you can buy known good heads (and have them shipped in) you may be able to save a little on the job. heads from an engine that threw a rod would be a pretty good bet.

 

do you know a good subaru shop in hiwaii??

 

but to answer your question, bent valves at the worst, no piston damage unless something much worse happened. which i have never heard of .

 

if you have the time, you can replace the busted parts, install a new belt and do a compression / leak down test. or just drive it and see. but if this is your only car and you need it yesterday, just get it fixed.

Edited June 2, 201213 yr by johnceggleston

John nailed it. You can replace the broken sprocket and any questionable idlers, hang a new belt and just see what it does, but there's a good chance it has bent valves. If the engine has been leaking oil or coolant from the head gaskets (common to leak externally on those) then this is as good a time as any to pull the heads and have them milled and put new gaskets in. Depending on how mechanically savvy you are, you could pull the engine and do the work yourself and only spend $500 - 800 on parts and machine work. Getting a shop to do it will be a couple $$$$.

 

Olnick (i think) is from HI, he might know of a good shop to take it to.

Too bad you're not on the Big Island. I know a guy over there. Oh well...

Olnick (i think) is from HI, he might know of a good shop to take it to.

 

Yes I am . . . and unfortunately no I don't!

 

2002ForesterGuy--I'd be happy to offer any input or help that I can (which may not be much!). Email me at ncarter1(at)hawaii(dot)rr(dot)com.

Also, the USMB member mtsmiths is from HI:

http://www.ultimatesubaru.org/forum/member.php?u=903

valves are not to badly priced 8 intake and 8 exhaust everyone iv'e seen loose belt gets evry valve bummer probly the coged idler pully failed and sent ball berrings trough evrything

replace the bent valves and call it good.

 

install a complete timing belt kit - belt, idlers, tensioner.