My newest gremlin is a thumping/knocking noise. I thought at first it was a rod knock. No noise when cold. After it warms up (a little) it makes a thumping noise at idle. It does not make the noise in park, only in gear. I put the car in the air and listen with a stehiscope. I can hear it clearly at the oil pump and in the oil pan. I can also hear it clearly in the rear of the trans. If i rev the engine the noise goes away. If i put it in park there's no noise at all at any rpm. I thought flexplate butt if so it should make noise all the time, not just after warming up some. I've never seen a trans noise being so audible all the way to the oil pump. Any thoughts?????????????. Help or ideas appreciated. Still planning on running Fontana on the 5th. If it breaks I'll know what it is huh.
I've got a knocking noise?
- Thread starter cuzimoto
- Start date
Hey! Looks like you did better last weekend. Figured you might chime in. I'm open this weekend butt I do wanna go to the street legal drags on Saturday. I want to run my wifes 82 bird also. Looking for mid 11's. Really weird with the GN. Runs real good. Still not perfect butt real good. I was gonna disconnect the torqe convertor to listen butt it don't matter cause it don't make the noise in park. I'd be happy to head your way.
I don't know. Just know the lock up has been removed. I installed a used supra engine for a freind that owns a trans shop and he rebuilt my trans in exchange. It makes a good clunk when it downshifts to first (sometimes). Another lesson learned. It is supposed to have stock stall of 2400 with no lock up and a shift kit.
boostmaster
Active Member
- Joined
- Aug 20, 2001
Noise
I've had that problem before. But from the sound of it, it could be your converter, flywheel, or converter bolts might be loose. I'd check the bolts first. But there is one thing that it can be that you really don't want it to be.........the thrust bearings. This usually happens when someone installs a transmission and don't line up the pilot on the converter and then bolt it up. The pilot will usually drop into the back of the crank but not without causing damage to the thrust bearing. I know from experience, had the same problem before and never found out what the problem was until I freshened the motor. By then the crank was done from all that walking in the block. Take a pry bar and see if the crank has too much back and forth by prying between the flywheel and the block and then back the other way. If it does thats your problem. Why does it only do it after its warm? The oil thins and that creates a bigger gap to fill. Not trying to scare you just giving you some suggetsions so you won't be chasing your tail.
I've had that problem before. But from the sound of it, it could be your converter, flywheel, or converter bolts might be loose. I'd check the bolts first. But there is one thing that it can be that you really don't want it to be.........the thrust bearings. This usually happens when someone installs a transmission and don't line up the pilot on the converter and then bolt it up. The pilot will usually drop into the back of the crank but not without causing damage to the thrust bearing. I know from experience, had the same problem before and never found out what the problem was until I freshened the motor. By then the crank was done from all that walking in the block. Take a pry bar and see if the crank has too much back and forth by prying between the flywheel and the block and then back the other way. If it does thats your problem. Why does it only do it after its warm? The oil thins and that creates a bigger gap to fill. Not trying to scare you just giving you some suggetsions so you won't be chasing your tail.
Originally I thought it was a rod or main bearing also. Hard to beleive that would be possable since I rebuilt the engine about 5k AGO. Oil pan gaskets been leaking some and I hate leaks so I'm gonna drop the pan and go ahead and check out all the bearings. STRANGE part is accelerating or cruising I don't hear anything. Only when 1100 rpm or less in gear. Rod or main bearings that make noise typiclly make more noise the higher the rpm.
Have had 2 do that over the years and both did exactly what you are describing and needed rod and main bearings......at idle warm and a knocking sound. Rev it up and it goes away. Good luck and hopefully you can just replace them with everything still in the car and not need a regrind.
TurboSpeed
Member
- Joined
- Oct 13, 2008
sounds like the same problem that i was having, only mine was rod side clearance, some rods were .023 and Ive heard if you have more than .015 it would sound that way, they say it would not bother anything as long as you can put up with the noise, and if your like me i dont like any ticking or knocking noise so im installing a forged steel crank and k1 rods that should solve it.
No I do not like noises comming from my engine nor do I like leaks. I took my wifes car to the track instead of the Buick. It's a lot more fun. If I'm slow at work this week I'll check the bearings and clearances since I want to fix the leak anyway and report back to everyone. If we're busy (which I'm hoping for) I should get to it next weekend. Either way I'll report back and thanks every one for your input.
