[MR2Fanatic]

Hey guys,

car: 99 Forester w/193k miles

So the car died on the freeway and just shut off. I brought it home and took the timing belt cover off to inspect. Apparently the cogged idler seized and shredded the belt - shown below in pics

So, just for the heck of it, I put a new pulley on it along with a new timing belt. I started up the car and it appears to run fine. Its a tad noisy with a type of clacking sound, however thats not too uncommon for these motors when cold. I don't know if its any louder than normal because its my friends car and I never really paid attention to it.

To confirm no damage, I decided to perform a compression test. I know a leakdown test would be better however I would believe that a very low number would confirm a bent valve not closing. The results are below and the results are 135-145 psi across all 4 cylinders.

What I'm looking for are some opinions or confirmation that the engine is fine prior to installing the new water pump and rest of the pulleys.

Any help would be appreciated.

Thanks



PICS of shred belt: (crappy cell phone pic)

PICS of compression test:

Video of engine running with new belt and cogged idler installed:
Notice the "clacking sound"

 

[Dan]

Wow! Blown belt and the valves survived? Go buy a lottery ticket while luck is smiling on you.

Oh, and welcome to the forum from a fellow MR2 fan: http://home.centurytel.net/danandmarcy/Beauty and the Bus.JPG

 

[MR2Fanatic]

Wow! Blown belt and the valves survived? Go buy a lottery ticket while luck is smiling on you.

Oh, and welcome to the forum from a fellow MR2 fan:

Looking good. Are you on MR2oc.com or mr2.com? I am and have the same screen name. BTW, I PM'd you the text to paste on this thread. I'd appreciate it if you could do it. Thanks

 

[Dan]

Sorry - just got back from the accountant and it looks like you beat me to it on posting pics.

I'm on MR2OC as WI-MR2. I haven't been on in several weeks, for some reason. Since we love all cars over here (okay, not quite "all"), feel free to post up pics of your MR2 over in The Relatives.

 

[MR2Fanatic]

anyone else have an opinion?

 

[RadcomTxx]

I would think that perchance the timing is off a bit?

 

[TC2000]

Seems it is a bit noisy, can you line up the timing marks and snap a pic for us.

 

[flstffxe]

get a listening probe out and try to closer isolate where the sound is coming from.

A long screw driver, dowel, mechanics stethoscope..... all work well.
For reference.
How to Rebuild Small-Block Ford Engines - Google Books

A bad tensioner also sounds a lot like rod knock or really bad piston slap.

 

[The Black Box]

That does not sound good. Probably is the tensioner.

 

[MR2Fanatic]

Ok here are the pics when the cams are straight up:

I do think that the tensioner is shot as it flops around alot. I have a new water pump, tensioner, and idlers that I'm gonna install now. If someone can confirm that the belt is on correctly that would be great. I'm gonna mark it anyway just in case. If you are wondering why I'm pulling the belt off again it was only temporarily installed to see if the motor was bad.

I cant let the motor idle for more than 30 sec due to no radiator installed. I have a new one coming in a few days. Once thats installed I will break out my stethoscope and take a listen to see if the noise continues after the engine has warmed up.

 

[TC2000]

timing marks look lined up to me

 

[MR2Fanatic]

ok, so I guess I'm one of the fortunate ones. Car is all put back together along with a new radiator and she purrs like a kitten. The new pulleys and hydraulic tensioner quieted things down alot.



Thanks everyone.

 

[TractionMax]

Quite the story.

Does anyone know whether or not this engine is a "clearance" or "non-clearance" engine? If it's a so-called "clearance" engine (valves cannot touch piston faces even when completely out of time), a broken timing belt while driving is not a big deal.

btw - with the given mileage, do you know if this timing belt / tensioner were all original?

 

[funkymonkey1002]

Quite the story.

Does anyone know whether or not this engine is a "clearance" or "non-clearance" engine? If it's a so-called "clearance" engine (valves cannot touch piston faces even when completely out of time), a broken timing belt while driving is not a big deal.

btw - with the given mileage, do you know if this timing belt / tensioner were all original?

Its an interference engine, the pistons and valves in 99% of cases collide, just not in this one i guess!

 

[Mi_ka]

If the belt snaps at the just right point then no harm is done.
Go get yourself into some lottery competition!

 

[adc]

If the belt snaps at the just right point then no harm is done.
Go get yourself into some lottery competition!

True, the timing chain on my 94 Toyota truck failed andeven though the engine is interference it was fine.

 

[pleiad7]

The SOHC engines are also a lot less likely to sustain damage than the DOHC ones.

 

[boxer25]

The SOHC engines are also a lot less likely to sustain damage than the DOHC ones.

Educate me please: Is this because the intake and exhaust valves are not controlled by a common camshaft on the DOHC engine and can get out of sync when the belt breaks, leading to intake and exhaust valves butting heads in the cylinder?

 

[Wormguy]

That's an amazing story! Do count yourself fortunate.

 

[ramontana]

Educate me please: Is this because the intake and exhaust valves are not controlled by a common camshaft on the DOHC engine and can get out of sync when the belt breaks, leading to intake and exhaust valves butting heads in the cylinder?

I would like the thinking on this as well.


thks