What causes insftalling a timing belt off timing?

Timing belts do wear out - they flex and bend literally millions of times while they last.
If you are having problems with timing belts wearing out before their rated lifespan, check the timing gears for misalignment, burrs, wear, or improper lubrication. Worn crank, camshaft or belt tensioner bearings may also cause problems with the belt. Also make sure the belt tensioner is working properly, with the rated amount of tensioning force.

No, sound more like you might have bent your valves when the belts shredded. Check your timing. check your timing belt. check the valves...

Timing on this vehicle should be computer controlled. There are not adjustments you can make to the timing except replace the timing belt. There is no Distributor adjustment and you can't access the vacuum advance to make adjustments there. If the timing is off there is a problem with the timing belt tension mechanism or timing belt, the vehicle on board computer or another cause for this. A loose timing belt would cause this and a bad tension mechanism would cause it both would give you timing that jumps around.

On smaller engines the timing belt should be checked regularly.When the belt breaks the camshaft stops turning and valves stay open at wrong time but the pistons keep moving and come up to top of cyclender and crash into the valves causing the first bit of damage.What I think happen to cause it to break again prematurly was somthing was still bent from first time causing resistance on belt which caused belt to break second time.These engines cant take that kind of abuse once never mind twice.I dont think second belt was installed wrong to cause this.Like I said the mechanic missed somthing bent or damaged the first time.But unfourtunatly this will be hard to prove.Unless you requested and still have old parts from first time work was done and can prove that it was mechanic neglegants.Good Luck.

as the timing belt usually turns the water pump yes it is possible. i am not sure what motor you have in this but i would think you ar elooking at your serpintine belt as your timing belt is behind plastic covers and is not visable. maybe your serpintine belt runs the water pump and as it is loose then it will not spin the water pump causing it to overheat

Timing belt not likely cause. If your timing belt is off, the car will not run at all. Need to know engine type to determine how many belts you have.
For overheating issues, please see tip at http://www.fixya.com/cars/r5929960-s_thermostat and let us know if you have more questions.

The belt has stretched causing the belt to jump timing. When you have a belt to jump a gear or pulley it causes more force on the teeth, breaking them off. That's a lot of torque when an engine turns over and the belt is stretched. It doesn't take much for them to break off, you're lucky the belt didn't break apart, it could have been a bigger mess with valves and head problems. Some belts should be changed every 100,000 miles, some say less. Good Luck.

90000 is a suffficiently long time for a timing belt. I'd listen to the dealership.

These water pumps are integral with the timing belt you must replace the timing belt with the water pump because the leaking water pump and antifreeze on the timing belt causes deterioration of rubber belt thereby causing imminent failure of timing belt destroying valves $$$ google" interference engine" for an explanation of interference engine

I cannot see any reason for the belt to cause timing belt to jump. unless they messed up something installing belt.might wanna get a second opinion