Help, please -- messed up timing belt job
12-25-13, 06:35 PM
#1
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Help, please -- messed up timing belt job
OK, my first post. 
I have a 2001 GS300, I'm doing a timing belt job on it. Everything was fine until I tried to remove the VVTI cam gear. Basically, I used an impact wrench and the hex bolt was so stuck and the impact gun rotated the camshaft by 180 degrees counter clockwise. Yes timing belt was off.
My question, should I go ahead pull the head or continue to finish the job like nothing happened and see later? I suspect bent valves, of course.
Please help, especially you know this 2jz-ge engine well or in similar situations before.
Many thanks!!!
I have a 2001 GS300, I'm doing a timing belt job on it. Everything was fine until I tried to remove the VVTI cam gear. Basically, I used an impact wrench and the hex bolt was so stuck and the impact gun rotated the camshaft by 180 degrees counter clockwise. Yes timing belt was off.
My question, should I go ahead pull the head or continue to finish the job like nothing happened and see later? I suspect bent valves, of course.
Please help, especially you know this 2jz-ge engine well or in similar situations before.
Many thanks!!!
12-25-13, 08:30 PM
#3
Dont worry, this happened to me too. I was replacing the VVTi cam gear O-Ring and had to remove everything. When I had to remove the VVTi cam gear, I also used an impact gun and rotated the gear. After reading manuals and tutorials, I was a bit confused because the information I was receiving was no consistent.
If you didnt mark your timing belt you might as well remove it all the way. Remove the spark plug out of Cylinder #1 which should be the one closes to the front of the engine. Grab a screw driver with a long shaft and drop it on top of the piston. Make sure the screwdriver shaft is about 7" or longer. While keeping an eye on the screwdriver handle, rotate the crank so that the screwdriver is at its highest point. Pay attention to the screwdriver movement as the piston goes up. So you rotate the crank, the screw driver is at its highest position, that is your Top Dead Center.
If youve done it correct, you will notice that the first white notched marking on the crank pulley is lined up at the 0 degree mark if im not mistaking. Once youre crank pulley is lined up, now it is time to line up the cam gears. On the back of the cam gears you will notice a metal plate with a marked white timing notch at the very top of the pulleys.
Now this is the part that gets kind of fuzzy because I forgot how to align these two. But what I do know is that for the VVTi cam pulley, you have 30 degrees of movement left and right. You twist it all the way to the right and that is where you will mark your notch. So when rotating your cam, you make sure that pulley is turned clockwise until "you hit the bottom" like it says in the manual.
Good luck sir.
If you didnt mark your timing belt you might as well remove it all the way. Remove the spark plug out of Cylinder #1 which should be the one closes to the front of the engine. Grab a screw driver with a long shaft and drop it on top of the piston. Make sure the screwdriver shaft is about 7" or longer. While keeping an eye on the screwdriver handle, rotate the crank so that the screwdriver is at its highest point. Pay attention to the screwdriver movement as the piston goes up. So you rotate the crank, the screw driver is at its highest position, that is your Top Dead Center.
If youve done it correct, you will notice that the first white notched marking on the crank pulley is lined up at the 0 degree mark if im not mistaking. Once youre crank pulley is lined up, now it is time to line up the cam gears. On the back of the cam gears you will notice a metal plate with a marked white timing notch at the very top of the pulleys.
Now this is the part that gets kind of fuzzy because I forgot how to align these two. But what I do know is that for the VVTi cam pulley, you have 30 degrees of movement left and right. You twist it all the way to the right and that is where you will mark your notch. So when rotating your cam, you make sure that pulley is turned clockwise until "you hit the bottom" like it says in the manual.
Good luck sir.
12-25-13, 11:51 PM
#4
Hope you all don't mind me piggy-backing on this thread as I have a separate but related question. I am about to change the timing belt and associated parts on my '00 GS300; first time trying something like this. I am concerned about keeping the alignment of the crank and cams at TDC while loosening the bolts. Question is, is it OK to leave the timing belt on until I loosen the pulleys on the two cams and the crank in order to keep everything aligned? My thinking is if something moves dramatically while loosening a bolt or two it will be relatively easy to put back to TDC and much less likely to cause damage.
12-26-13, 07:46 AM
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Thank you VIP and Daniel, that gave me some relief. I set the timing before this happened. The crank and the exhaust didn't move, it's the intake moved. So I rotated it back and hope everything is OK.
ttaylor, I would leave the timing belt on to loosen the pulley bolts, then hand tighten them back until I'm ready to take them off --- if I have to do it again. To be safe, I would use the Schley tool to hold the crankshaft in position and find some way to help the camshafts not to move -- I don't want to put too much stress on timing belt, the only thing holding it from rotating othwise.
ttaylor, I would leave the timing belt on to loosen the pulley bolts, then hand tighten them back until I'm ready to take them off --- if I have to do it again. To be safe, I would use the Schley tool to hold the crankshaft in position and find some way to help the camshafts not to move -- I don't want to put too much stress on timing belt, the only thing holding it from rotating othwise.
12-26-13, 12:20 PM
#6
Hope you all don't mind me piggy-backing on this thread as I have a separate but related question. I am about to change the timing belt and associated parts on my '00 GS300; first time trying something like this. I am concerned about keeping the alignment of the crank and cams at TDC while loosening the bolts. Question is, is it OK to leave the timing belt on until I loosen the pulleys on the two cams and the crank in order to keep everything aligned? My thinking is if something moves dramatically while loosening a bolt or two it will be relatively easy to put back to TDC and much less likely to cause damage.
12-26-13, 04:22 PM
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another blunder
OK, I think I made another blunder. 
Look at the attached pictures. I found the mistake when I tried to put the crank timing gear back. It was stopped by that little piece of brass tap. I think I bent it when I pulled the gear out. (Couldn't believe that I missed it. I will blame bad lighting.
)
Now my questions: what is the function of it? Can I just bend it back? Was the original form straight?
Thanks a lot, guys!
Hope the car is still drivable after so many mishaps.
Look at the attached pictures. I found the mistake when I tried to put the crank timing gear back. It was stopped by that little piece of brass tap. I think I bent it when I pulled the gear out. (Couldn't believe that I missed it. I will blame bad lighting.
)Now my questions: what is the function of it? Can I just bend it back? Was the original form straight?
Thanks a lot, guys!
Hope the car is still drivable after so many mishaps.
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12-26-13, 04:42 PM
#8
The "brass tap" you refer to is the timing gear retainer. I guess its job is to prevent the timing gear from coming off in the event you lose the crank pulley. Very unlikely situation lol. But that piece is not really necessary to put back if you damaged it beyond repair. If it still looks ok then you can bend it back and put it in. Only thing you need to watch for is when you pulled off the timing gear and bet that piece. Make sure you didn't break any of the teeth off of the timing gear. If it's missing any, then you have to replace the gear or else the car will run like crap.
As for bending valves, yes it can happen if you're not careful. If you had the crank set at the sub mark which is the yellow mark on the pulley when you spun the cam then you're ok. If it was on the white mark (actual TDC) then you may have bent the valves.
The best way to test if you messed up the valves is to do a compression test after you put the timing belt back on and have it timed correctly. If there is a low cylinder, then that's the one you bent. The other option is to use a leak down tester and test each cylinder one by one. Using the leakdown tester you can do the bent valve test without setting the timing belt back on. Just rotate both cams so that the cylinder you are testing has the valves closed on both sides.
As for bending valves, yes it can happen if you're not careful. If you had the crank set at the sub mark which is the yellow mark on the pulley when you spun the cam then you're ok. If it was on the white mark (actual TDC) then you may have bent the valves.
The best way to test if you messed up the valves is to do a compression test after you put the timing belt back on and have it timed correctly. If there is a low cylinder, then that's the one you bent. The other option is to use a leak down tester and test each cylinder one by one. Using the leakdown tester you can do the bent valve test without setting the timing belt back on. Just rotate both cams so that the cylinder you are testing has the valves closed on both sides.
12-26-13, 05:29 PM
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Hey, Jeff:
Thanks a lot for your input. I will bend it back and the timing gear is fine.
I put the timing at the first mark on crank pulley (round dots on cams, not the lines), I think it's 15 or 30 degrees before TDC? This is the better situation that you mentioned, right?
Another question, I forgot how deep the gear should go in, should I press it all the way in until it stops? (Not a big force though? )
I bought your VVTI O-ring a short while ago, Because it's not leaking and the crank seal seems not leaking either, I think I will skip these 2 this time because of the uncertainties, -- I'm not even sure if I bent valves or not. Plus I don't have the proper tool to press the crank seal in. The cam seals were not leaking either. But the valve gasket leaks a lot and timing belt showed early signs of separating. My car has 114k on it.
If they need to be replaced, I will do it again and it's no big deal after this first time.
OK, back to work now.
BTW, your videos are very helpful!
Thanks a lot for your input. I will bend it back and the timing gear is fine.
I put the timing at the first mark on crank pulley (round dots on cams, not the lines), I think it's 15 or 30 degrees before TDC? This is the better situation that you mentioned, right?
Another question, I forgot how deep the gear should go in, should I press it all the way in until it stops? (Not a big force though? )
I bought your VVTI O-ring a short while ago, Because it's not leaking and the crank seal seems not leaking either, I think I will skip these 2 this time because of the uncertainties, -- I'm not even sure if I bent valves or not. Plus I don't have the proper tool to press the crank seal in. The cam seals were not leaking either. But the valve gasket leaks a lot and timing belt showed early signs of separating. My car has 114k on it.
If they need to be replaced, I will do it again and it's no big deal after this first time.
OK, back to work now.
BTW, your videos are very helpful!
The "brass tap" you refer to is the timing gear retainer. I guess its job is to prevent the timing gear from coming off in the event you lose the crank pulley. Very unlikely situation lol. But that piece is not really necessary to put back if you damaged it beyond repair. If it still looks ok then you can bend it back and put it in. Only thing you need to watch for is when you pulled off the timing gear and bet that piece. Make sure you didn't break any of the teeth off of the timing gear. If it's missing any, then you have to replace the gear or else the car will run like crap.
As for bending valves, yes it can happen if you're not careful. If you had the crank set at the sub mark which is the yellow mark on the pulley when you spun the cam then you're ok. If it was on the white mark (actual TDC) then you may have bent the valves.
The best way to test if you messed up the valves is to do a compression test after you put the timing belt back on and have it timed correctly. If there is a low cylinder, then that's the one you bent. The other option is to use a leak down tester and test each cylinder one by one. Using the leakdown tester you can do the bent valve test without setting the timing belt back on. Just rotate both cams so that the cylinder you are testing has the valves closed on both sides.
As for bending valves, yes it can happen if you're not careful. If you had the crank set at the sub mark which is the yellow mark on the pulley when you spun the cam then you're ok. If it was on the white mark (actual TDC) then you may have bent the valves.
The best way to test if you messed up the valves is to do a compression test after you put the timing belt back on and have it timed correctly. If there is a low cylinder, then that's the one you bent. The other option is to use a leak down tester and test each cylinder one by one. Using the leakdown tester you can do the bent valve test without setting the timing belt back on. Just rotate both cams so that the cylinder you are testing has the valves closed on both sides.
12-26-13, 05:30 PM
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12-26-13, 08:56 PM
#14
Jeff,
Glad you weighed in on this one. I was about to change the TB on my '00 gs300. I was wondering about the front crank seal. I planned on changing the cam seals and the front crank seal only if it was leaking. I saw your videos on replacing the TB, cam seals, tensioners, WP, etc., but couldn't find the one about changing the front crank seal. Is there a video or do you have pics?
Glad you weighed in on this one. I was about to change the TB on my '00 gs300. I was wondering about the front crank seal. I planned on changing the cam seals and the front crank seal only if it was leaking. I saw your videos on replacing the TB, cam seals, tensioners, WP, etc., but couldn't find the one about changing the front crank seal. Is there a video or do you have pics?
