Timing belt saga...Dealer says lower end is gone?

[grahams98]

Timing belt broke on 2000 Camry 2.2. So I read up on this forum and brought in a mechanic buddy as didn't think I was up to the task. We get everything off and go to line up the mark on the balancer but encounter resistance turning the crank as we're trying to line it up the zero degree mark. My buddy talked with the dealer today and they said that it's most likely that the lower end of the motor (crank,etc) is gone/going and that is what likely the cause of the timing belt breaking. We're going to drop the pan tomorrow to inspect but I'd love some informed advice.

BTW: we removed the plugs to be sure that it wasn't just compression resistance.

BTW2: It's at 187,000 miles so I thought I could more life on this one.

[JohnGD]

Timing belt breaking should not cause problems except stranding. You'd read plenty owners had that. But the belt might have snapped because of the resistance problem. So pull the pan and inspect. See what might have seized up.

[carsrus]

Oil pump could have gone to crap and eaten up the timing belt.

Its highly unlikely but possible. If you were doing high rpm for a while before the belt broke its possible. When the belt starts to tear and rip b/c of something seizing the oil pressure drops.

[71Corolla]

Seeing all the rotational force comes from the crank, I can't think of a way a lower end engine problem would cause a timing belt to break. Maybe the balance shaft assembly is failing and causing the crank to jump?

[nitronate33]

Originally Posted by 71Corolla

Seeing all the rotational force comes from the crank, I can't think of a way a lower end engine problem would cause a timing belt to break. Maybe the balance shaft assembly is failing and causing the crank to jump?

+1, the timing belt is turned by the crank, so any resistance on the crank itself would only cause damage to other internal parts, there would be no effect on the timing belt itself.

[Mister_Perkins]

pull all the spark plugs and try to rotate the engine. With the spark plugs installed, the compression cannot escape easily. With the plugs removed, should rotate relatively easy.

[grahams98]

Thanks, we will give that a look as well. The spark plugs are out and we only encounter resistance turning the crank as it nears the zero mark. We are going to inspect the other pulley that's turning along with the crank and see if something else is obstructing free movement. We are also going to drop the pan if that fails.

What the dealer mechanic said is that since the only connection as far as turning force goes is the timing belt that the top end will continue to spin after the bottom end seizes which will cause the belt to break. My wife was just pulling the car out of the driveway and was accelerating up to speed 50 feet from where it was marked overnight. It's pretty likely that she didn't warm it up thoroughly since she do great at that but she didn't hear any of the thumping normally associated with lower end crank issues.

[Mister_Perkins]

Well, driving the car cold will likely not cause the belt to break.

There must be another problem, With the belt off, spin each pulley and see if one of them makes noise or has excessive play. All the pulleys should be tight and not turn very easily. Even the idler pulleys and tensioner pulley.

[grahams98]

checked everything else externally and then dropped pan. Something is clanking when we turn the crank manually but can't see exactly where. Please direct me to any threads that would help.

The lower end of this engine has a lot going on in there and it has been years for me.

[Mister_Perkins]

I'de drop the engine balacer, then you can get a better picture of whats going on.

Grab each connecting rod and move them around.

Did you have any metal pieces in the pan?

[grahams98]

There's is some brass in the pan not huge chunks but not good...

[Mister_Perkins]

small particles, in dust form is OK in a small amount. If you have large pieces such as 1/8" thick or larger, you've got a problem.

[grahams98]

Nothing that large, but larger than I would have liked to have seen. Maybe 1/16th thickness with a total volume of the metal in the pan equal to roughly a 1/4 to 1/2 teaspoon (mostly dust).

The Haynes Manual is really adamant that the balancer is a no-touch zone...is it okay to pull that out as long you don't remove anything else?

[Zembonez]

If the bottom end locks up at speed, it's entirely possible for the inertia of the top end components to shear a timing belt. Obviously you are on the job already checking the lower end. The brass in the pan is not a good sign at all.

Hope it comes out favorable!

[Mister_Perkins]

Yeah you can remove the balancer. Just make sure the bottom end is TDC before removing it, and use a paint marker to mark the balacer off.

If you look on the one side of the balancer, you can see it has a couple Circles on the outside. This houses a gear assembly on the inside of it that helps dampen vibrations from the engine. Mark off Vertically (From the case of the balancer, onto the Circles that connect to the gears inside). Once you mark them off, simply disconnect the oil pickup, and remove the bolts for the balancer. It will drop out and two shims will fall out too. Make sure to mark off what side and the direction they come out.

When installing, make sure the balance cams are lined up, place the shims ontop and install the bolts.

With that much dust, that's really not a good sign though.