timing belt self destructed

[nynor]

i think i might vomit...

timing belt is only 2.5 years old, my daily driver. maybe 20K on the belt.

car died coasting to a stop light. replaced fuses, just in case. changed to spare DME relay. then took the distributor cap off and cranked it over. no movement.

then i took the upper timing cover off. sure enough, the belt was not broken, even seemed like it had the proper tension. however, about half of most of the teeth were missing, and the belt was shredded lengthwise about 2/3 of the way around.

towed the car home with a borrowed chain and the wife's discovery.

now what? i know i'll be removing the head... where to begin.

[Karl2bdc]

Well, thats where you begin, remove the head and take it to a shop to check out how many valves are shot. Just think of it as an early way to get your head rebuilt and the headgasket replaced I had my head rebuilt at a local speed shop (who actually does mostly fords and chevys) when my belt went (i got lucky with only 1 bent valve). I orderd all new sleeves, seals, and the valve and shipped them straight to them, and they charged me 100 bucks to take it apart, machine it, put it all together, 3 angle valve job, etc. Not the end of the world by any means. You can get a rebuilt head from lindseyracing for 500 bucks if you want to just go that route.

Curious, how was the belt tensioned when it was replaced? My belt went because the previous owner who did the belt job, took out the timing belt idle roller because i guess he thought it wasn't necessary. I figure it got to slapping around and stripped, just like yours.

[nynor]

it was done properly. in fact, i think it still has proper tension on it.

[seaboltman]

Oh man that sucks. Good luck with everything.

[85944na]

I'd guess that not all of the rollers were replaced and one seized, or one of them was defective, that or your waterpump went but then you'd be running hot.

[jm951]

You might have gotten lucky, retime the engine, put a new belt on and do a compression check. Odds are that you bent valves, but if you don't have to remove the head, why do it? A compression check would tell you that. On another idea, if the belt is the age and proper tension as you say, it shouldn't have done that. For it to shred multiple teeth, you might have an oil leak that softened the belt (I've seen that one a couple times) or something else seized that the belt was driving, like the timing belt idler. Or the bal shaft belt went and caused the rest of the failure. If the belt is the age you say and properly tensioned, I'd bet on the timing belt tensioner sproket siezing at this point.

Back to the current problem, check to be sure you bent valves first. You might have gotten lucky.

[nynor]

no oil leak that i can see. in fact, the belt looks damn clean. balance belt looks proper. what are the odds that none of the valves are bent? billion to one?

[jm951]

You never know, but I would about bet they are bent. It is possible that you didn't but don't bet against it. Odds on, you bent a couple, but why not make sure first? From the lack of a major, ongoing oil leak, I'd say your idler sprocket seized.

[AFJuvat]

Your valves are bent.

I would venture to guess a siezed roller and\or an improperly tensioned belt.

Pop the head off and take it in. Use the opportunity to get your valve guides and seals replaced.

AFJuvat

[nynor]

idler sprocket sounds about right.

[nynor]

is there anyone else out there that thinks it is worth the time to do a compression check?

[scheistermeiste]

thats sucks, but i thought it was supposed to be replaced ever 2 years or 40k miles, which ever came first?

and there is one less kitten in the world...

[nynor]

3 years... i was on it for next spring.

[vital-transform]

age is just as important as miles...rubber gets brittle 30K or 2 years max
in fact you will soon see a advisement on all tires sold, warning about the effects of age on tire performnce!

[ae1969]

You bent valves...... I can't recall one belt that has not bent a valve?

Its actually not as bad when you really think about it.......

As has been mentioned perfect time to rebuild the head.

[bryanthompson]

Welcome to the order of the bent valve... My valve job was right about $2k, expect to be in the same ballpark.

The way I heard it, you replace every 3 years MAXIMUM. Tension checks at 5,000, 15,000, 20,000 and replace at 25,000.

[nynor]

2K? are you kidding? did you do the work yourself?

[bryanthompson]

No, I didn't do it myself. You can definitely save a ton of money if you can do it yourself.

*bryan digs out old invoice for t-belt break repair*

Parts:
4 exhaust valves: $225
1 gasket set: $110
1 timing belt: $36.80
1 balance belt: 55.90
1 92704 roller: 93.50
1 24103 roller: 41.50
2 20504 gears (that word's unreadable, so i may be wrong): $51
1 02507 Roller: 40
1 guide: 11.5
1 hose: 7

Total: $756 in parts, $810 in labor. $1881.03 after taxes. Not quite $2k.

[AFJuvat]

No, it isn't worth doing a compression check at this point. In fact, you are likely to bend more valves doing the check.

Easiest way to check for bent valves at this point is to remove the cam housing and look at the valve springs - You will see one or more valves "down"

Take the head to a machine shop and have all of the valves checked. It is possible to have 1 or 2 valves ever so slightly bent that it is hard to see.

As far as what the total damage would be, I've seen people get away with 1 or 2 valves, 3 - 4 is about average, 5+ is not uncommon

Some of your valves (exhaust) likely took a double hit - when you pop them out, you will see two bends in the valve - those valve guides are now destroyed.

You can do it yourself for less than $1500 (parts and machine shop costs) When I do one here at the shop, it normally runs around $2000.

The one thing to check at this point is to try to determine WHY this happened. Look at everything very closely. If you miss anything, you will be doing this again within 3 minutes of you starting the car.

Sheared teeth indicate one of the following:

1: Improper belt tension (belt too loose)
2: Siezed roller\waterpump\etc
3: Oil soaked belt

I would, at this point, replace all of your rollers and tensioners. Check the waterpump for free spinning of the pulley. Also check the waterpump for axial play.

Good luck

AFJuvat

[nynor]

if this is going to cost $1500, it is isn't worth it. the car is worth less than 3K, probably less than 2.5K.