Timing belt

timing-belts
geo
belts
prizm

#1

i just bought a 91 prizm with a toyota

1.6 mfi dohc 4cyl engine with 200,000 miles

runs good ,passed smog no problem, i dont

know if the timing belt has been replaced

and wonder how difficult it is to change it?


#2

It is fairly difficult. The drive belt(s) have to be removed; the vibration damper/crankshaft pulley has to be removed; the right engine mount has to be removed; the belt covers removed; the tensioner released; and the belt removed. When installing the new belt the valve timing marks have to be aligned. The rest is reassembly. The real tough point is breaking the crankshaft pulley bolt loose and retightening to the specified torque. You have to block the crankshaft from turning if you do not have impact tools. So if you don’t have the tools and knowledge for this, farm the whole job out. If you decide to go ahead, get the Chilton or Haynes manual and read the procedure over so you know what it entails.

With this many miles on the Prizm you will have to decide if you want to replace the water pump and idlers at this time. It sounds like you don’t know the maintenence history of this Prizm so the age and mileage on the WP and idlers is in question.

Good luck on this.


#3

My daughter had a '91 Prizm. She and I replaced the timing belt in my garage at home in about 4 hours. We had a service manual and all the necessary tools. If you don’t have a manual and a good supply of tools you probably shouldn’t attempt it.

If you have a manual and tools, however, it’s not a terribly difficult project. It just takes some time and patience. All of the things Researcher says need to be removed are correct. Removal of the right front wheel and fender liner are necessary to access to the crankshaft pulley bolt. You’ll need a jack to support the engine when you remove the right side mount.

I think there were two different engines in 1991. The water pump on my daughter’s engine was not driven by the timing belt, but you might want to replace the pump at the same time, just beacuse it’s so much easier after you have everything else out of the way.

If the water pump on your car is driven by the timing belt you should definitely replace it when you put the new belt on.