[Vettezuki]

I've got about 85K miles on my 02 Mazda Protege 5. I can tell the engine is definitely running noticably ruffer and I'm assuming it's the timing belt.

Anyone have any idea how difficult a job this might be to do at home. I've done a fair bit of work on cars, but never a timing belt on Japanese motor.

[SeanPlunk]

Originally Posted by Vettezuki

I've got about 85K miles on my 02 Mazda Protege 5. I can tell the engine is definitely running noticably ruffer and I'm assuming it's the timing belt.

Anyone have any idea how difficult a job this might be to do at home. I've done a fair bit of work on cars, but never a timing belt on Japanese motor.

No clue how hard it is to do, but I'd love to learn if you decide to do it at your house.

[ls1z28]

Bring it on over.

[enkeivette]

Changing a timing belt on an interference motor is always a good idea. I've done it on two FWD cars, it's a severe PITFA.

If the timing belt jumped a tooth, you'll want to replace the tensioner too. But if it really did jump a tooth, it should have also thrown a code. You can check visually: pull the viewing plate off the timing belt cover, spin the motor till the little marks on the cam gears line up. If you can't get them to line up, it did jump a tooth. If they do line up (at the 90 degree position), check to see if the mark on the crank snout is lined up with the scribe on the balancer, or block, or cover, or wherever the hell it is.

[Vettezuki]

Originally Posted by enkeivette

Changing a timing belt on an interference motor is always a good idea. I've done it on two FWD cars, it's a severe PITFA.

. . .

WTF is an interference motor?

[ls1z28]

One the pistons hit the valves when the belt breaks. I don't belieave yours is an interference motor I will check and see.

[ls1z28]

Ben the recommended belt change for your car is 105,000 miles.

[Vettezuki]

Originally Posted by ls1z28

Ben the recommended belt change for your car is 105,000 miles.

Well, at 85 I'm pretty far from hat. I'll have to bring it over and you can listen to what I'm hearing.

-b

[enkeivette]

Originally Posted by Vettezuki

WTF is an interference motor?

The pistons chase the valves as they return to the seat. If the belt or chain breaks, the piston(s) will smack the valve(s) bending them. Common on all motors with adequate lift and decent compression.

This is opposed to a motor that would be able to make a full revolution with the valve at max lift, without the piston hitting the valve.

When I lost the timing belt on the Neon all 16 of my valves were bent. If you want a souvenir I've got plenty.

New valves The top end should be good for another 100K miles now.