: spun bearing maybe.....

08-16-11, 02:12 PM
So my new motor runs which is a plus but there is a loud noise comming from the lower end. I disconnected the TC thinking it might be that but the noise is still there. Also the motor is very hard to turn over by hand. And the noise seems to get louder the longer then motor runs. I am finishngs the exhaust this weekend and am going to find where the noise is commin from. But I am wondering how hard is it replace a rod bearing? Can I do it myself or should I just say the hell with it and send it back to the.machine shop and not see the motor for a month.? PS ssorry about not posting recently got a new job and really can't be on the phone all day.

08-16-11, 02:19 PM
Is this a newly rebuilt motor? If so, ABSOLUTELY send it back to the machine shop.

08-16-11, 02:58 PM
Damn, it sucks because the shop will probably have the motor for the rest of the summer. You would have to raise the motor a little so you can get the oil pan off, after that, you'd have to find out which one is spun and replace it. Hopefully its a rod and not a main bearing. But if you can put a motor in a car, you should be able to replace a rod bearing without taking the motor out. If its a main bearing, you'd have to drop the whole crankshaft and it would be hard to replace one without scratching the crank with the motor in the car.

08-16-11, 03:31 PM
Ya lets hope its not a main bearing. Ya so much for driving the car by the end of the summer. Although it does sound awesome with the straight headers on it LOL. What noise does it sound like when its a main bearing. Is it like a grinding noise off and on.

08-16-11, 05:50 PM
Rod and main bearings sound like a loud knock, like someones hitting the block with a hammer or something.

08-16-11, 07:09 PM
Okay this is like a grinding noise that's on and off its not hammer like.

08-16-11, 08:10 PM
Grinding on and off like maybe an AC clutch?

08-16-11, 08:36 PM
Take the belts off, start the car (don't let it run long!), and see if the noise is gone.

08-17-11, 09:17 AM
Ya but it.sounds like it is comming from the lower end. Is it possible I tightened something to much because I used the adapter plate to bolt the tranny up. Also the noise gets louder the longer the engine runs.

08-17-11, 10:19 AM
Hard one, gonna have to get under there and see if you see any shavings. As far as the motor, I can't think of anything that would grind.

08-17-11, 11:08 AM
If you think it's the bottom end, take the oil filter off and cut it open. If you got something failing in there, it will have metal in the filter paper.

08-17-11, 06:06 PM
Ya that's Wat I'm thinking drop the pan and check it out.

08-17-11, 06:09 PM
No you don't have to drop the pan, just take the oil filter off and cut it open. Do you have metal in the filter?

08-17-11, 10:34 PM
Idk I will check this weekend. The Guy who s shop I have been paying to use turned weird all of a sudden and told me I couldn't use it anymore. Guy gave me two days notice. I told him ill take it out by the end of the month which I am paid through. But I am getting it out Tomorrow to be on the safe side. Guy turned out to be a shady character its to bad because he knows his stuff when it comes to GM.

08-18-11, 01:20 PM
Bad rod bearings will start out as a subtle knock and eventually turn into a "death screech" as the lining of the bearings is worn away. See if you can use a stethoscope (or a length of 5/8" heater hose) to zero in on the source.