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ase_master327
ase_master327, Shop Owner
Category: Toyota
Satisfied Customers: 5288
Experience:  +15 years experience with Toyotas. Bumper to bumper diagnosis & repair.
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Can a bad crank timing sensors cause a loud knock.

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1994 tercell with loud knock. Hoping its not bottom end parts.

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Unfortunately, a crank sensor will not cause the engine to knock. This sensor helps the computer control ignition system timing, and has nothing to do with crankshaft operation, other that telling what position it is in. If the sensor is bad, or damaged, the engine will not run at all.

The only other thing is the flywheel and/or torque converter. Torque converters, come loose, and when they go bad make this knocking noise, that sounds like a lower end engine knock.

To find the noise, get a length of hose about 2 foot long, and put one end to your ear, and the other to the origin of the noise (like a stethoscope), this is quick and very effective.

If you stil need help, just reply.

ase_master327 and 2 other Toyota Specialists are ready to help you
Customer: replied 9 years ago.
what do you think about throwing bearings and retorqueing the rods to try to get aquick fix on a bottom end problem?

The way the berings are lubricated is by oil pressure only... Oil is injected between the bering and journal through the passages in the block and crankshaft.

What causes the knocking is lack of lubrication, this is from clogged passages, or a spun bearing. Both surfaces are destroyed when this happens.

If you take it apart and the surface of the crank is perfectly smooth, clean it with some emery cloth and put it together. Just make sure the clearence is within specification. This usually only happens when an engine spins a bering and immediately locks up, most people junk the engine. I'm still driving on one that it happened to about 10 years ago, and all I did was slide in one rod bearing.

If the crank is not perfectly smooth when you take it apart, then the engine needs another one. Crank kits are not very expensive when compared to the cost of another engine.

If you need specifications, and such, just let us know.

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Customer: replied 9 years ago.
thanks so much sounds like good advice.