Slipped Snapped Broken Timing Belt T-Belt [merged]

[aznerd11]

a few weeks ago, my car started idling poorly so i never started it since. i checked for vacuum leaks, but i then found it to be a problem with the timing belt. When i lifted the top cover, i noticed a rip on the belt and the belt off a few teeth on the exhaust sprocket. So now im in the process of changing it but now im stuck. Please see pictures.

rip
http://img.photobucket.com/albums/v387/bboygenius016/tbelt011.jpg

off teeth on exhaust
http://img.photobucket.com/albums/v387/bboygenius016/tbelt010.jpg

after 1/4 turn of the crank, the teeth lined up again, which made it skip some more
http://img.photobucket.com/albums/v387/bboygenius016/tbelt012.jpg

how do i get the timing to TDC with the teeth off?- i started turning it softly but then i felt a restriction and it moved itself counterclockwise.
also how do i get the crank sprocket off without the tool?
This is on a 90 laser turbo

 

[Pure92TSi]

You've got a better chance of marrying Jessica Simpson than your valves not being bent. I'm goin through a head swap at the moment. At least yours will all be free...must be nice.

 

[endlessMyk]

I was only cruising at about 35 when my belt got shredded, and it didn't even snap the whole way, half of it just was torn off. All valves were bent. The loud clunk you heard, yeah, you might wanna put money on needing new pistons, too. Do a compression test, if you get 0's, then you need all new valves at least.

 

[tstkl]

you do realise that if you didnt hear anything when your sister tried to start the car, its because all the valves are already bent and they didnt hit the pistons because of that.... think about it, if you take the timing belt off and try and start your car, youll hear the pistons crush the valves, if you dont, the valves are already crushed....

 

[DSMcrazy3]

what are the chances of the valves being bent going 45...good, bad, any personal experiences?

It's not based on speed, it's whatever your RPMs are at when it happens. Mine broke at idle and I bent 2.

 

[TransDSM]

Pull the head and check you might have gotten lucky. I was part of the .001% that had a timing belt shred while taking off from a stop and came out of it without one bent valve. Not a single tweaked valve. The Mitsubishi mechanic was amazed. That was awhile ago now and I have never had a problem since. So who know you might have gotten lucky but the way you describe what happened it doesn't sound promising. When mine shredded the car just died with no thump. Sucks it happened, hopefully it isn't too bad

 

[TJGoSurf]

I'm willing to run the pool.

13 out of 16 is my guess.

 

[Drift_SM]

well i might as well put my own bet in...

i say 12 valves and 1 piston - my luck is bad..so hench my bet


i should have the numbers by monday or tuesday.

 

[AnkurJ0217]

How many miles has it been since you swapped the timing belt previously? or if you know if when the previous owner(s) changed the timing belt? I have a 99 GST with 93k miles (just bought it few days ago)...idk when the last time the belt was changed. Im scared .

 

[Old Mitsu Tech]

Doesn't matter how many you bent. Bent valves mean head removal. Just make sure new belt and tensioner, idlers and water pump are replaced. Since you are getting it done for a song and a dance. Log your miles on this and change at every 60k after that. Happy DSM'ing. Oh and by the way. Since 1991 I've seen around 6 engines break, throw, mill the teeth, etc on the timing belt and survive absolutely unscathed. It can happen but it's darn rare.

 

[GST with PSI]

i got lucky with my timing belt issues. my balance shaft belt shredded and caused my timing belt to jump three teeth. my crankshaft was 3 teeth out of phase with my cams, but my cams were still in phase with each other. it was at idle when it happened and after the balance shaft belt went, it was running like crap, making it seem like i had some bent valves. worst day of my life. luckily i took it apart and it was OK. i didn't have bent valves, but because my motor was so far out of time, it made it run like it did. i got lucky. and not many, such as yourself do. I'm sure you bent all 16, especially after you gave it one last crank after the belt was broke. hey, i guess if your going to go out, go out big right?

 

[SinaiTSi]

How do you do a compression test if you can't get your car to turn over? In the directions, it says get your car to normal operating temp. thanks.

 

[speed127]

I'm gonna put my 2 cents in.... if your gonna take it all apart and probably have to put new stuff in why not go bigger and better? my guess is all valves and no pistons.

 

[Drift_SM]

Doesn't matter how many you bent. Bent valves mean head removal. Just make sure new belt and tensioner, idlers and water pump are replaced. Since you are getting it done for a song and a dance. Log your miles on this and change at every 60k after that. Happy DSM'ing. Oh and by the way. Since 1991 I've seen around 6 engines break, throw, mill the teeth, etc on the timing belt and survive absolutely unscathed. It can happen but it's darn rare.

why do i have to replace water pump and idlers?

 

[DSMcrazy3]

why do i have to replace water pump and idlers?

You don't, "have to".

but think about it this way. Say you get all that work done(not replacing the timing belt, idle pulley, tensioner, water pump, etc..) and you get the car back together, for a pretty penny. Two months later those finally give it, if something goes very wrong with those pulleys, or tensioner, there goes your timing and there goes your valves and probably pistons in that case.

Those things are just things that get taken off, or see a wrench while pulling the head, so why not replace them since you're there. It's kinda like going to the grocery store for vegetables, but you hardly have any meat at the house. You get home, start to cook, but realize you need meat. You have to go back.

 

[Drift_SM]

good point...we didn't get a chance to take the engine apart tonight, but defiantly tomorrow. ill be sure to document the adventure.

ironical today when i was brousing around the parts shop...under the stairs, beneath a busted Evo bumper and card board was a wood crate with the an old 4G63 from a 97 eclipse. i ripped it open and there was 4 mint condition pistons!!!!....i cleaned em up and plan on using them if one of mine is damaged. I suspect that this came from a person who had crank walk. because the bearings were worn...but the pistons were mint.
even the rings looked good.

 

[JREPeru]

well it depends how long di you keep driving asfter the blet brok or did you turn it off right away if you kept driving the there is a 90% you might need a valve job

 

[Drift_SM]

well it depends how long di you keep driving asfter the blet brok or did you turn it off right away if you kept driving the there is a 90% you might need a valve job

um....no it does not depend on how long i was driving.....its impossible to keep driving....

the engine stalls right after the belt brakes....How could you think it would still run? WTF

when the belt brakes the engine cuts out right away, and the damage is done..depending on what your RPMs are will determine the number of valves bent, tweaked, ect...

this is because when you belt brakes the cams move - (out of timing, with the crank) - so which ever valves are down when the piston comes up get hit because your crank is still rotating for a few moments

i hope i explained that somewhat correct.

 

[Old Mitsu Tech]

Well, let's put it this way. It is an "interference fit" engine. This means at different times the pistons and valves occupy the same space. Key word being time. If you throw the belt, break the belt, shear the teeth off the belt, or anything like that the valves and pistons try to occupy the same space at exactly the same time. The results are bent valves at best, destroyed engine at worst. It doesn't matter if you are idling or running at 6000 rpm. Only in that if you are idling you probably won't destroy your engine. I've seen both sides. Neither one are pleasant. Like was said, when this happens your engine instantly is in a non running state until all and I mean all repairs are made.

The reason I suggest all the replacements is why would you want to do it over if one of these items fails later? Unless you know the others are new or very near new you run the risk of them failing and you are back to square one. I was trying to prevent you possibly ruining your engine if an idler or tensioner that you didn't replace fails. At least if it is new and you have the documentation you can get some sort of warranty depending on where you purchased the parts and consequently who installed them. Albeit the water pump is not driven by the timing belt, try to change it without pulling the timing belt and you will see what I mean. At least on the 4g63 engine.

Hope this cleared it up.

 

[Drift_SM]

im doing a new tensioner, but what idlers are your talking about..can you be a lil more specific.

thanks for all your help.

 

[Drift_SM]

we did a compression test tonight.

the numbers are

cylinder
..1.........2..........3..........4
179____178_____0______0

we did the test 3 times on each cylinder each time was about the same.

tomorrow night were going to take it apart and repace whats needed. also doing all the gaskets.

more info soon.

 

[mgcook]

6 bolt swap!!!!!

 

[BOOstGhost]

agreed.

 

[Catbox_95]

My balance shaft belt broke at 6,000 rpm and got lodged in my timing belt, causing it to slip. It appeared that I only bent all 8 intake valves, but at the head shop they noticed that I just slightly bent 4 exhaust valves too. No piston damage, just scratches. And a couple broken rocker arms.

So, a re-cap:

6,000 rpm
12 bent valves
0 piston damage
2 broken rocker arms

Not too bad. I feel I was lucky, especially at that rpm.

 

[Old Mitsu Tech]

The answer to your idler question. Idler pulleys are pulleys that the belt goes around and runs upon which serve no purpose other than guiding the belt. They are very important in that if they go out, they will and do occasionally seize which results in pulling the head again as they then burn the belt because they are not turning. Buy a complete timing kit with new tensioner if this is the route you are going to go. As far as 6 bolt swap, I guess this is as good a time as any, but let me iterate this. Put a new belt, tensioner, idlers, and water pump on the new engine "before" you install it. Much easier that way. And please make sure the tensioner is set properly. I can't stress this enough. That's where a lot of people get in trouble.

Good Luck

 

[Drift_SM]

Today we took off the head.
I'm sending it out to get pressure tested and checked over.

heres a pic of the valves...it ws surprisingly not bad at all. at most 8 valves at least maybe 4. - we know for a fact the intake valves on cylinder 3, 4 are bent because we could see it. but the 4 other exhaust valves on 3, and 4 could be tweaked.

heres a pic, cant tell much but w/e. the cause of the belt brake was the old tensioner was bad.


it goes 1234 left to right in this pic.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

to those who think the car is riced out...your right

i bought the car 3 months ago and I'm in the process of de ricing it with the help of my boss aiding in the re do of my gsx. lots of work, body, engine and interior are being done soon and i cant wait to show you...the car will be unrecognizable in a few weeks.