ibmer
01-30-2006, 04:36 AM
I recently purchased a 1990 BMW 325is which ran fine, and needed only
minor cosmetic care. I am now learning about "interference" engines.:(
I am also learning why when I asked my mechanic for an estimate to
repair the damage (caused, no doubt, by age and a backfire after
I power washed the engine.), he advised me that the car was "toast" .
- $1500 labor to replace the belt and head.
- $500 plus parts to rebuild the head.
I thought that too much to spend on this old timer, so I'm doing it myself.
Chilton says the Torx screws and bolts can not be reused.
Haynes recommends cleaning and chasing the holes and bolts.
I did the latter.. Comments?
Both manuals refer tangentially to a sping belt tensioner.
The tensioner in the car has no spring.
None of the replacement tensioners come with a spring, but I have found
a tensioner spring and spring bolt in a parts list.
Chilton recommends that the tensioner be replaced when changing
the belt, and that it be upgraded to a compatible tensioner.
The roller bearing in the tensioner looks fine to me.
I hate to replace it just because I don't know how to set the tension.
My gut says it should be snug enough to take up any slack after
I've spun the crank shaft a few times. ( About what a spring might provide.)
Can anyone offer advice?
minor cosmetic care. I am now learning about "interference" engines.:(
I am also learning why when I asked my mechanic for an estimate to
repair the damage (caused, no doubt, by age and a backfire after
I power washed the engine.), he advised me that the car was "toast" .
- $1500 labor to replace the belt and head.
- $500 plus parts to rebuild the head.
I thought that too much to spend on this old timer, so I'm doing it myself.
Chilton says the Torx screws and bolts can not be reused.
Haynes recommends cleaning and chasing the holes and bolts.
I did the latter.. Comments?
Both manuals refer tangentially to a sping belt tensioner.
The tensioner in the car has no spring.
None of the replacement tensioners come with a spring, but I have found
a tensioner spring and spring bolt in a parts list.
Chilton recommends that the tensioner be replaced when changing
the belt, and that it be upgraded to a compatible tensioner.
The roller bearing in the tensioner looks fine to me.
I hate to replace it just because I don't know how to set the tension.
My gut says it should be snug enough to take up any slack after
I've spun the crank shaft a few times. ( About what a spring might provide.)
Can anyone offer advice?