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My daughter was driving and broke down with a major coolant leak and car will not start. Figured out probably a water pump failure/seizure. Started timing belt replacement and ran into the following problem. Have the top timing cover off and the belt is still on. When I turn the crankshaft to line it up to 0 the camshaft is not turning. Crankshaft turns but belt doesn't move! How do I get the camshaft and crankshaft lined up? When I take the belt off, can I turn them separately to line them up?
I have the crankshaft bolt off (used the starter bump method mentioned in these forums, worked like a charm) and will remove the pulley tomorrow along with replacing the water pump.
Also, I have the car up on stands and in park. Went to put it in neutral but shifter won't move and the front wheels move freely when in park. Does the car have to be in neutral for the timing belt change? Do I have other major problems besides the timing belt?
Yes your engine is non interferance which means you may turn the camshaft pulley or the crankshaft pulley and you don't have to worry about the pistons hitting the valves.
You might need a cheapo compression tester though, in order to make sure your crankshaft is at top dead center for when you put a new timing belt on. (there are two positions that little mark on the pulley or crankshaft could be on, one is tdc and if you turn the crank one full turn, it isn't on tdc. the only way to know when you are at tdc is with a compression tester (or some other way to seal and feel compression in the spark plug hole).
So line up your camshaft mark and then screw in your compression tester in the spark plug hole of #1 (the closest to the front of the engine, that is, the side with all the pulleys). Turn the crank until the mark on the pulley, or crankshaft (depending if you already have the pulley off) lines up with the mark on the engine. Now look at the reading on your compression tester - if you are at tdc you'll have a reading. If you aren't, you will have no reading, so turn the crank exactly one more time and now you have GOT to have a reading.
You can turn the crank with the engine still in gear if you have to. the front wheels of course, must be free to turn in order to do this. Naturally it's better to have the transmission in neutral when you are trying to turn the crank because there will be a lot less resistance and it will be easier to turn.
Last edited by AlmightyCamry777; 06-11-2010 at 04:05 PM.
I did get some replies in the Camry Generation 3/4 section and was able to successfully change the belt and water pump. The water pump had seized and caused the belt to jump. Another way I found to see if the crankshaft is at TDC is to simple put a long, clean dowel down the #1 spark plug tube and you can then watch it move up and down. My biggest obstacle was the crankshaft bolt. I was able to get it loose by wedging a breaker bar in the front suspension/steering parts and bumping the starter for a second. To get it torqued correctly I was able to access the flywheel teeth from underneath
and hold the flywheel with a large screwdriver while I tightened the crankshaft bolt. The car runs like its brand new and my daughter is very happy. This was my first timing belt change, and I'm glad I attempted it and was able to save hundreds of dollars by doing it myself.
Another way I found to see if the crankshaft is at TDC is to simple put a long, clean dowel down the #1 spark plug tube and you can then watch it move up and down.
What if you were on an 'exhaust' stroke instead of compression stroke? Looks like the dowel method would only give you a 50/50 chance of being right. Maybe I'm missing something here.
My understanding from reading other forums is that when the dowel travels to highest point that is the compression stroke. It makes sense because if you have a compression gauge hooked up as the piston moves up it is creating the pressure measured by the gauge, as the dowel moves down it releases the pressure (exhaust stroke). I watched the marks on the crankshaft and camshaft move as the dowel went up and down and made sure they were lined up when the dowel reached its highest point. I also noticed that the spark plug boots I had laying in the tubes would pop up when compression was created by the other pistons. Seemed logical to me and it worked, but then again maybe I got lucky. Thoughts?
What if you were on an 'exhaust' stroke instead of compression stroke? Looks like the dowel method would only give you a 50/50 chance of being right. Maybe I'm missing something here.
I think if you were on the exhaust stroke, the dowel would not move at all, because the piston compression pressure is all going out the exhaust port?
Whereas, when you are at TDC - both intake and exhaust valves are closed. So the only place for the compression pressure to go is out the spark plug hole.
Last edited by AlmightyCamry777; 06-12-2010 at 12:42 PM.
I think if you were on the exhaust stroke, the dowel would not move at all, because the piston compression pressure is all going out the exhaust port?
Whereas, when you are at TDC - both intake and exhaust valves are closed. So the only place for the compression pressure to go is out the spark plug hole.
Huh!? The dowel is resting on top of the piston and that has to move equally as far for either stroke.
Huh!? The dowel is resting on top of the piston and that has to move equally as far for either stroke.
Youre right. i thought the dowel was supposed to cover the spark plug hole and only move in reponse to engine compression.
Simply putting the dowel down the hole naturally only tells piston position not tdc (it would be a 50/50% guess).
When I used the dowel in the #1 spark plug hole, I also watched the both the camshaft and crankshaft marks. TDC is found when both marks line up, this was also when the dowel was at its highest point. It takes 2 revolutions of the crankshaft to rotate the camshaft once. If you are just watching the crankshaft mark line up to 0, then you can be at either the compression or exhaust stroke. The movement of the dowel confirmed this: Crankshaft lined up at 0, camshaft mark not aligned = exhaust stroke and dowel at lowest point. Crankshaft aligned at 0 and camshaft aligned with its mark, dowel at highest point and TDC.
When I used the dowel in the #1 spark plug hole, I also watched the both the camshaft and crankshaft marks. TDC is found when both marks line up, this was also when the dowel was at its highest point. It takes 2 revolutions of the crankshaft to rotate the camshaft once. If you are just watching the crankshaft mark line up to 0, then you can be at either the compression or exhaust stroke. The movement of the dowel confirmed this: Crankshaft lined up at 0, camshaft mark not aligned = exhaust stroke and dowel at lowest point. Crankshaft aligned at 0 and camshaft aligned with its mark, dowel at highest point and TDC.
Okay, that makes sense. I must have missed that the first time reading this. Glad you had a successful timing belt replacement.
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Thank you,
Compression v exhaust
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