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

 

[ryanxiii]

I thought my Balance shaft belt had skipped but it didn't look like it had when I opened up the covers. Does anyone know what elese would cause the car to vibrate hard enogh for things to rattle at idle. Could the Crank pully deteriorate enough to cause this?

Later,

Ryan 95 Tsi FWD A/T
Las Vegas

 

[fastwaytech]

Oil pump sprocket not lined up when timing belt was done or is no longer lined up correctly.

 

[huafist]

It's worth noting that the oil pump sprocket can line up at TDC and the rear balance shaft still be out of phase. The only way to tell is to take out the check bolt in the rear of the block (level w/balance shaft, holds nothing on,) and stick long screwdriver through the hole. If it doesn't go in very far, the rear shaft is out of phase. You'll have to take the timing belt loose and spin the oil pump sprocket another 360* to bring it into phase.

 

[PennStateJoe21]

Ok, well Ill start by telling you I have a 97 TSI AWD with a 6 bolt swap. Drivin home on tuesday I noticed a loud tapping noise and I knew it wasnt my lifters. Popped the hood and my timing belt shifted about 1/4" to the right on the cams and was rubbing on the lower shield. So just to be sure it actually skipped I lined up the dows (straight up and down) and the timing marks on my cams. They lined up perfectly. Still not convinced I did a leak down test. This is where it gets confusing. When I ran air into the #1 cylinder and opened the throttle I heard air in the intake. Ok bent intake valves. Tried it on the #4 cylinder. NOTHING, sealed up tight. Now considering the 1 and 4 run in unison why did the #4 check out fine?? I still have my balance shafts in and I think that belt went and caused my timing belt to shift or jump. Why else would the #1 be leaking? Valve seals? head gasket? Is it possible for the belt to jump on the crank but stay perfect on the cams?? Please any help or insight would be great!! Thanks for reading, Joe

 

[tfoti]

It is totally possible to have your crank skip and have the cams perfectly lined up. It happened to me and bent all my intake valves. Take your timing cover off and take a look. But how does your car run? Did you just hear tapping and then you shut it off? Or did it start making noise and it just quit?

I'm a little confused as to how just valves in one cylinder can be bent. I don't see how its possible. But if this is worth anything: when the number 1 cylinder valves are open the #4 are closed.

 

[PennStateJoe21]

The car was running good. I was driving when i heard the noise (hard to hear over the exhaust) so I didnt get on it but everything felt fine. When I pulled over I shut the car off...the turbo timer kept it running for 40 seconds so I jumped out and popped the hood and thats when I saw the timing belt and called for the flat bed. But it was running before I shut it off. Ok so if it did jump at the crank why is my #4 checking out but the #1 isnt on the leak down test?? Im really just about to say screw it and rip the head off!! This is frustrating!! Thanks for the help, I appreciate it, Joe

 

[tfoti]

By leakdown test do you mean compression test? Leakdown tests your piston rings, you need to do a compression test to check cylinder compression. Even if your cams were off by one tooth it would idle horribly, might not run at all. From the sounds of it you probably did not bend any valves since if your timing went out of whack your motor still has momentum even after the car shuts off therefore still turning your crank/cams and bending valves. All my intake valves got screwed at idle, sounds like you have a different problem. But you still need to get that timing belt tightened properly before you do bend valves.

 

[PennStateJoe21]

Nah, I did a leak down test..You can tell if air is escaping through intake or exhaust valves with it which would be the case if they were bent... Check it out http://www.dsmgrrrl.com/FAQs/leakdown.htm

 

[GTM]

Nah, I did a leak down test..You can tell if air is escaping through intake or exhaust valves with it which would be the case if they were bent... Check it out http://www.dsmgrrrl.com/FAQs/leakdown.htm

Ummm, when #4 is up on ignition, #1 is on the rock. That means the cylinder has just about finished exhausting and the intake is opening (rock, overlap, rocking, etc.) thus will have NO compression.

You must check each cylinder at ignition at TDC for that cylinder.

Cheers,
GTM

 

[PennStateJoe21]

Yeah I know...I brought each piston to TDC before testing it and tested each cylinder separately

 

[PennStateJoe21]

At TDC all the valves are closed, so if there is any air coming out of the intake or exhaust manifd then you got yourself some bent valves

 

[GTM]

At TDC all the valves are closed, so if there is any air coming out of the intake or exhaust manifd then you got yourself some bent valves

Explain what you did and how you determined TDC?

Cheers,
GTM

 

[tfoti]

Doubtful you have bent valves man. Your car wouldn't run, it would've quit when the timing jumped. Open your oil caap and look for your rockers. If they are just floating willy nilly then your valves are bent. But its doubtful

 

[GTM]

Doubtful you have bent valves man. Your car wouldn't run, it would've quit when the timing jumped. Open your oil caap and look for your rockers. If they are just floating willy nilly then your valves are bent. But its doubtful

I don't understand why he didn't just do a compression chk first. Thought I explained it but he seems to think that when both pistons are up they are firing like a 2 stroke... oh well. What worries me he's trying to out think this and will end up getting himself into serious trouble.

Cheers,
GTM

 

[tfoti]

I don't understand why he didn't just do a compression chk first. Thought I explained it but he seems to think that when both pistons are up they are firing like a 2 stroke... oh well. What worries me he's trying to out think this and will end up getting himself into serious trouble.

Cheers,
GTM

For sure. Just do a compression test, let us know the numbers. If one cylinder is really low, i'd say maybe headgasket. But if your car is running fine you dont need to worry about bent valves. Get your timing belt readjusted, buy a new tensioner, whatever made it shift like that before mr. piston meets mr. valve

 

[Defiant]

Drivin home on tuesday I noticed a loud tapping noise and I knew it wasnt my lifters.

Rod or balance shaft bearing. Possibly a belt tensioner bearing.

Popped the hood and my timing belt shifted about 1/4" to the right on the cams and was rubbing on the lower shield.

That's not "jumped timing".

Do the compression test.

 

[GTM]

Rod or balance shaft bearing. Possibly a belt tensioner bearing.That's not "jumped timing".
Do the compression test.

I visited that site and while I didn't read everything I most certainly am not a happy camper.

http://www.dsmgrrrl.com/FAQs/leakdown.htm

Line #2 is what I expect from some mechanics but this girl is flirting with danger bordering on insanity. It's bad enough she suggests using a screwdriver she offers using a 3/8" drive extension (she calls it an extender) which is even stronger. Can you imagine what will happen should she pull the engine through with especially with the 3/8 drive stuck in the hole and a valve opens...

People, use a 3/16" or 1/4" wooden dowel, then should a valve foul on it at least it will bend the dowel.

Line #6 is where our poster got the idea he could do both 1&4 plus 2&3 at the same time. Maybe that's not what she meant to say but for sure it is absolutely INCORRECT.

Wonder how many others have taken their head off only to find no bent valves.

Cheers,
GTM

 

[PennStateJoe21]

first off I never said #1 and #4 fire at the same time...I said they run in unison..meaning each will be at top dead center at the same time and the test works if its done right. Ill do a compression test when I get home from work today and let you know the numbers. Hopefully itll be warm out! Thanks, Joe

 

[khartley]

Ok, I was driving and I got into boost and the car (91 GSX, 167K miles on all original engine) started running like crap, like it was on 2 cylinders or something. I thought it was ignition, and replaced a bunch of stuff but I did a compression test a few days ago, and the first 2 cylinders read 0...I think it jumped timing but I'm not totally sure...maybe it just skipped one tooth...cause it still runs and everything, my datalogger shows no knock until 5000 rpms, then it shows about 120 counts. So I do think it is timing related, but here's the thing...I had to drive it like that for a little while, only back and forth to work, for about a week. So I probably put about 20 miles on it like that. So do you think I'll be safe just getting a new head, or will I probably need a whole new engine?

 

[95gstHRCsuper20]

Are you doing the work or having somebody else do it. First things first check the timing belt, every single tooth if it is ok you need to redo compression check and keep all data remove all plugs and disconnect cas this shuts off fuel. After taking first readings add 1 teaspoon of oil to low cylinders, 15 psi lower than average of good. If compression goes up then ring problem and block needs work. If it stays it is only a head prob. Take advantage and have head ported and polished by machine shop. Get cams turned and come out flying.

 

[GTM]

...
So I do think it is timing related, but here's the thing...I had to drive it like that for a little while, only back and forth to work, for about a week. So I probably put about 20 miles on it like that. So do you think I'll be safe just getting a new head, or will I probably need a whole new engine?

While rare and much less common than years past it is possible to have deposits break off when removing spark plugs and then when doing a compression check they will lodge on the valve seats. This will give compression readings of 15-25 psi until you re-start, run, and recheck the compression.

If you did check using 3-4 compressions each while throttle was held wide open then in all probablility you have burned or bent valves on #'s 1-2. Pulling the valve cover you should see all the spring hats at the same level when the cam lobes are up (use a straight edge across several). If not, then bent valves. It probably isn't doing it a lot of good driving on 2+ cylrs for they are trying to do the work of 4 and can get damaged from heat but 20 miles over a week isn't bad.

You will have to pull the head to determine how extensively it is damaged and worn. You didn't mention what the compression was on the 2 good cylrs. Recheck compression and then go from there, yes, could have damaged guides with bent valves. This does not mean the head can't be fixed, you will just have to evaluate costs.

Cheers,
GTM

 

[kris_leblanc]

Hi, I own 3 talons, two turbo awds, and one 91 non turbo fwd. this car had a new timing belt and water pump installed by a mechanics shop not too long ago, maybe 9thousand k or so. i was cruising in third the other day and all of a sudden it dies, i coast to a stop, pull off the timing belt cover and notice it snapped clean in half. there were two small cracks elsewhere on the belt. i am pulling the motor (first time for me) and am going to try to rebuild it. any suggestions as to what went wrong, what might be damaged, and places of any good non-turbo engine rebuild guides?
Thankyou so much,
Kris LeBlanc

 

[plastic_phork]

Is the non turbo the one that had the timing belt break?

 

[K_Hill]

Yours valves are more than likely bent. Is this the turbo car or non-turbo car? Go to www.vfaq.com and they have directions on anything you want to know about your car.

 

[kris_leblanc]

this happened on the non-turbo. it died so quickly at such low rpms though... i wasnt racing or nothing, i drive it pretty easy. i am planning to take it apart and rebuild it, i just completed a rebuild on an engine in college and learned quite a bit, so i want to rebuild this one to see if i can, so that i can rebuild one of my two poor turbo cars that dont run.