Hi I have a 1970 lesabre with high compression 350. I really like this car, its my first Buick engine. I have been chasing a fan belt noise. As of right now, all the belts are off all of the pulleys. The harmonic balancer is off also. When the motor is running There is still a squeaking or squealing noise coming from what i think is the front of the motor. I dont want to start throwing parts at this with having a better idea of what is going on. I was thinking maybe a bad oil pump, Timing chain? Any help would be greatly appreciated. Thanks
Squealing 350
- Thread starter Scott Z
- Start date
have you used a mechanics stethoscope to more closely isolate the noise source?
you can get a cheap one from Harbor Freight
http://www.harborfreight.com/mechanics-stethoscope-69913.html
or you can just use a long screwdriver.
the Buick oil pump is driven off of the distributor shaft which is driven by the camshaft. you've also got the front main crankshaft bearing up there, so there's a lot of different places for there to be a bearing or shaft rubbing.
is there any metal in the oil?
if you wind up doing a full tear down, be sure to look at the articles on improving the oil passages. TAPerformance.com timing covers are pricey but very nice and also provide an oil flow bump.
the 71 shop manual will cover pretty much everything you need to know about servicing your engine for a stock rebuild. only major difference is that the 71 has deeper dish pistons and lower compression / lower power.
http://www.teambuick.com/reference/library/71_chassis/index.php
you can get a cheap one from Harbor Freight
http://www.harborfreight.com/mechanics-stethoscope-69913.html
or you can just use a long screwdriver.
the Buick oil pump is driven off of the distributor shaft which is driven by the camshaft. you've also got the front main crankshaft bearing up there, so there's a lot of different places for there to be a bearing or shaft rubbing.
is there any metal in the oil?
if you wind up doing a full tear down, be sure to look at the articles on improving the oil passages. TAPerformance.com timing covers are pricey but very nice and also provide an oil flow bump.
the 71 shop manual will cover pretty much everything you need to know about servicing your engine for a stock rebuild. only major difference is that the 71 has deeper dish pistons and lower compression / lower power.
http://www.teambuick.com/reference/library/71_chassis/index.php
how many miles does this engine have on it?
how many since the last rebuild, if it's ever had one?
it may well be time to just get an engine kit ( rings / bearings / gaskets / seals ) and just give it a refresh. the car is 45 years old, after all.
the factory rear main seal is rope, if doing a rebuild be sure and get one of the neoprene two piece gaskets. better sealing ( when properly installed ) and less drag than rope.
if, somehow, this noise is coming from inside the convertor then this would be an excellent time to try to find a 200r4 transmission to swap in. that will give you both a shorter 1st gear ( better launches ) as well as overdrive ( taller top gear ) for lower cruising rpm and better fuel mileage.
how many since the last rebuild, if it's ever had one?
it may well be time to just get an engine kit ( rings / bearings / gaskets / seals ) and just give it a refresh. the car is 45 years old, after all.
the factory rear main seal is rope, if doing a rebuild be sure and get one of the neoprene two piece gaskets. better sealing ( when properly installed ) and less drag than rope.
if, somehow, this noise is coming from inside the convertor then this would be an excellent time to try to find a 200r4 transmission to swap in. that will give you both a shorter 1st gear ( better launches ) as well as overdrive ( taller top gear ) for lower cruising rpm and better fuel mileage.