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[RESOLVED] Timing Jumped, Bent Valves?

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mikelv

15+ Year Contributor
566
10
Jun 17, 2006
Columbus, Georgia
Yeah, I'm sure this one has been out there, but please get me on track, I'm about to lose it all together.
The car won't turn over....
I went to turn the motor over by hand, to check timing marks, crank style and the intake cam gear jumped, I can't tell if the belt skipped or not, but I'm pretty sure it did? Right before the cam gear "jumped", the timing belt to have severe slack in it between the cam gears, then the intake cam gear like "popped" over and the slack retracted. (Making sense??)
When I installed the timing belt, I went exactly by the book, and the auto tensioner is within spec of the manual, and the belt felt ok. What did I miss? What specific about the tensioner pully did I miss?! Initially, I turned the whole engine 6 roatations and everything lined up fine! I even pulled the "lazy" exhaust cam to line up? I screwed up somewhere?

Did my timing belt jump and how can I tell? How can I tell I bent valves short of pulling the head? I can't check compression, because the car won't start? It wants to turn but has the symptoms of plug wires misrouted? (misfiring)

Did I bend the valves guys? Tell me there is something simple I can do, and tell me what more info you need from me for productive advice! Thanks all!:thumb:
 
Did you by chance turn the motor over counterclockwise? If so, you can jump timing. You should ALWAYS turn the motor over clockwise. That keeps the slack-part of the timing belt where the tensioner is. If you turn it over the other way, you apply tension to the tensioner part of the timing belt, compress the tensioner, and the tbelt gets slack.

So you heard it jump time while manually turning the motor over and then tried to start it? If so, you may have bent valves. If you just jumped time while manually turning it over and stopped there, you probably just have to re-time.

What guide did you follow when you did this?
 
Here this should help.http://www.dsmtuners.com/forums/articles-engine-fuel/182787-how-change-your-timing-belt.html Once youve got it timed correctly you can do a compression check. To do this you pull all the plug wires. Take out your plug and screw in the compression tester. Now have a buddy hold the throttle wide open, and have him/her turn the engine over till the gauge stops rising. Pay attention as to how each cylinder builds pressure on each compression stroke. Also be sure that your engine is at operating temp:thumb:
 
Did you by chance turn the motor over counterclockwise? If so, you can jump timing. You should ALWAYS turn the motor over clockwise. That keeps the slack-part of the timing belt where the tensioner is. If you turn it over the other way, you apply tension to the tensioner part of the timing belt, compress the tensioner, and the tbelt gets slack.

So you heard it jump time while manually turning the motor over and then tried to start it? If so, you may have bent valves. If you just jumped time while manually turning it over and stopped there, you probably just have to re-time.

What guide did you follow when you did this?

Thank you for the input. I'm sorry for being quite vague last night. I'll see if I can explain the situation a little better. I'm sorry, I'm just stressed out to the max over this.

What I had to do was replace a crankshaft, main bearings and rod bearings. Assembly went fine, and everything was ok. I timed the engine before re-installation. The method I used is the same method I've always used when timing the engine, and I also had my Haynes Manual for refresher.
I'll explain the best I can off the top of my head what happened and what I did.

Starting with the crankshaft and connecting rods. Before timing belt installation, I gently rotated the crank back and forth a few times (no complete rotations) just to ensure the bearings were well lubricated and the rotating assembly moved freely. From there I installed the Crank Sprocket, Disc, Gear, Oil Sprocket, Front Case, and all other related items. Balance Shafts excluded.
Then will all pistons and connecting rods nowhere near the top of the cylinders, I rotated the Cam Gears in a clockwise direction until the Dowel Pins faced the 12 o'clock position (upward) and the timing marks were aligned exhaust 3 o'clock and intake 9 o'clock. Then once the Cams were aligned TDC, I gently rotated the crankshaft and rotating assembly clockwise until my timing marks on my crank angle disc were aligned. Oil pump timing marks not being an issue in respect to no balance shafts. Once all my timing marks were aligned I installed the belt in the following sequence.

Compressed the auto tensioner and placed a small allen key to hold tension. Tq to spec

The moved the tensioner pulley so the two small holes faced to the left as you look at the front case. From there I pulled the pulley back hand tight tension, and tightened the bolt hand tight.

Using my left hand to hold the belt, I started the install at the tensioner pulley, routing in a counter-clockwise direction from tensior pulley, crank, oil, pulley, intake, then finally exhaust cam.

Ensured that I held the "lazy" exhaust gear with a 17mm wrench to ensure timing marks were aligned. Also ensure timing marks on the crank were good as well.

From there I tightened the tensioner pulley to tq spec, using a pry to compress the auto tensioner, and released the allen key. Measured the length of the depressed piston, and was within spec. This tensioner is bran new.

From there I rotated the entire assemble six times in a clockwise direction to ensure the timing was good. Actually I did it twelve times.

Okay, everything is hunky dory, fast forward:
complete install, turn key, car runs like doo- doo....did not test drive, only idle.
major vacuum leaks from TB Gasket, and TB Bolts loose. One thing I notice is the timing belt is excessively loose. More than normal, but I've read about reasons for loose timing belt. Subsequent to turning off the car, ect.... ect...

My problem here is I think I screwed it up the second go around, I can't remember even turning the crank more than once or twice the second time!

But what happen either way is afterward, the car fired up, drove it fifty feet at 2000 rpm avg, and swung back in the drive way. This is where I discovered the bad vacuum leaks.....idle in the drive way.

Killed the car, fixed the leaks, went to fired back up and never started again. Had the symptoms of misfiring, firing orders i.e. spark plugs wire misrouted.

Turned the crank in a clockwise direction, got about half way, and the belt created huge amount of slack, and I watched the intake cam "pop" ....the same way it snaps when your turning the cam gear w/o a belt installed. You know? The springs retracting. The thing is right before the "pop" the engine was never difficult to rotate? There was no indication that something was binding, or anything was making unwanted contact. It just turned, the belt looked loose, and cam gear "popped"

So, my question is if this car jumped a sprocket sitting there, or sometime during that idle or small drive, I bent those valves correct? I mean, if I belt valves and lost timing during operation, wouldn't the car just die right then and there???

My next step is to uninstall the belt, and reset timing. Manually turn the engine in a clockwise direction, and see if everything moves smoothly. Maybe I got lucky?

Is there anything else I missed here, and also, what am I missing about the timing job!?!?!
What specific am I missing regarding the tensioner pulley, and if you don't have the Mitsubishi special tool, what do I need to ensure I do correctly this time. Belt tension, how do I know I'm right?!
I mean how do I judge that beyond measuring the length of the exposed tensioner piston, and rotating the motor? I'm using the Haynes Manual as a guide, and always have the VFAQ opened up on my favorites. What is with the damn pulley that's so important, and what do I need to do to ensure it's in the right position before I tq it down?
I was under the impression that the special mitsu tool is just to compress the piston enough to pull the allen key and the auto tensioner does the rest, meaning as long as that item is serviceable, your in the green?
Help me out guys! :sosad:
 
I'd read through the following link including the articles it links to. That will explain things I think more clearly than Haynes. Maybe you'll realize you did something wrong/different, maybe not. After you retime, check your compression as tbonitz301 suggested, maybe even on a cold motor just to see if a cylinder is obviously out.

http://www.dsmtuners.com/forums/art...l-installing-timing-timing-belt-6bolt-2g.html
 
To me it sound like you timed the motor correctly, but you placed the belt on incorrectly. What I mean is that you may have aligned the intake and exhaust cam straight up with the #1 piston at TDC, BUT you may have placed the belt with slack on one side of the motor.

You may have placed too much of the belt on the oil pump (intake cam) side of the motor and too little of the belt on the tensioner pulley side. This would cause excessive slack on the oil pump side and too much tension on the Tensioner Pulley side. The auto tensioner would have been nice and tight, but all the play would have been on the intake cam/oil pump side of the motor. The exhaust cam would have plenty of tension, but very little on the intake side.

At idle and cruising conditions it would be fine, but the second you begin to decelerate, you end up placing even more slack on the intake cam side of the motor, and then the belt may have skipped there.

Everything above is theoritical, and that's the best I can do without the car in front of me.
 
Thank you Jeff, at least I can better understand the possibilties.
After work today I'll re-time the car with this case in point.
What do I need to do to ensure the slack is not prodominately on the intake cam/ oil pump?
 
Just keep the tension equal on both sides. You can tell when one side has more slack then the other.
 
Yeah, I'm pretty sure the valves are bent.

I re-timed the car, and everything manually turned over ok, just I didn't hear the pshhh sound of the compressed air in the cyl everytime i turned it..

Tell me this is normal, and I got lucky, because from my exp. this isn't normal and I'm totally screwed.

Sorry, I'm not exactly happy about this. :mad:

Guess I'll put it back together and try it.

Bent Valves :sosad:
 
I just re- timed the car, and she wont even start to to a compresion check

When I was turning the motor over manually to verify the marks, the motor didn't even make any compression noise.



The only thing that happens is the motor wants to turn, then the exhaust just backfires.
 
Sorry to hear, but I already knew you were f**ked the first time I read the thread. I just didn't want to give you the bad news. When timing skips the way you mentioned, you most likely were in motion and that just keeps the motor running even though timing is already lost. This just keeps the pistons and values continously hitting each other, instead of the motor stalling immediately.
 
Yeah well, I'll pull the head today and see the extend of the damage.
I hope the pistons will be ok. They're Wiseco (coated) so there's a good chance. The car rolled about twenty feet so hopefully the small engine load didn't do too much.

My guy will hook me up so it shouldn't be so bad. Turn around on the machine work will be about a week. No big deal, hey it happens. :|

Okay, Sunday I pulled the head off the car and this was just as I suspected.
From rolling out my driveway with improper time, caused me to bend 11 valves out of 16. That's batting over .600! :rocks:

The guides were fine, and no other significant damage was present. The Pistons were also fine, and no signs of warpage anywhere.

Right now, waiting for machine work to be completed and shoud have the car running by the weekend.

I'm not happy about all the gaskets and such that needed replacement. Let this be a lesson to all who are over-zealous in completing a project.

Intake Manifold Gasket, Head Gasket, Exhaust Manifold Gasket, CAS O-ring seal, Cam Seals, Valve Cover Gasket Set, Valves, and possible Timing Belt depending....all this at a minimum. :|

Well, I ended up paying $580.00 for parts alone shipping to my door via UPS ground. I also ordered a HKS Kevlar Timing Belt. This is not including machine work which is estimated around $350.00 or more. Now, if you decided to have a shop do your work, then you can do the additional math on that.
 
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