Engine knock after torque converter install.
On The Tree
Joined: Jan 2023
Posts: 144
Likes: 54
Is causing a knock.
I guess I'm too old to make up the terminology.
No sir. The piston is hitting the crankshaft counterweight ever so slightly, due to the bent rod. The piston is causing the knock, but I guess it is the rods fault. Well no…it’s the injectors fault. What were we talking about again? 😜
Staging Lane
Joined: Nov 2007
Posts: 79
Likes: 7
Can you pull the converter bolts all the way out and push the converter back and then run the engine? It should slide back away from the flex plate 1/4 inch or more. If it won't, that's also a telling sign that it wasn't seated properly and is crushing the pump in the trans.
A buddies car made that same sound just after he hit the TB button at the starting line.
I would have sworn it was a rod bearing.
He drove it home, it turned out the flexplate was cracked around the crank bolts. Stock flexplate btw….which have no business on a 9 second car.
I would have sworn it was a rod bearing.
He drove it home, it turned out the flexplate was cracked around the crank bolts. Stock flexplate btw….which have no business on a 9 second car.
TECH Fanatic
Joined: Jul 2007
Posts: 1,802
Likes: 332
From: Wilmington, De
Cracked flexplates and loose converter bolts will sound like rod knock. If this noise started after the torque converter was installed, I would be looking at the installation of the converter. Separate it from the flexplate (you don't have to pull the trans to do this), and fire the engine back up. Either the noise will remain or it will disappear, and then you will know whether the issue is with the engine or the transmission.
On The Tree
Joined: Jan 2023
Posts: 144
Likes: 54
Cracked flexplates and loose converter bolts will sound like rod knock. If this noise started after the torque converter was installed, I would be looking at the installation of the converter. Separate it from the flexplate (you don't have to pull the trans to do this), and fire the engine back up. Either the noise will remain or it will disappear, and then you will know whether the issue is with the engine or the transmission.
TECH Addict
Joined: Oct 2016
Posts: 2,513
Likes: 480
From: PDX-OR-USA
If you have grade 8 bolts holding the converter on, then the spacer material under the converter should be grade 8, those look like home depot imported galvanized washers.
their thickness consistency is questionable and they don't look like they are lining up so their hole is bigger than the bolt.
You should use hardened machinists washers that fit the bolts, and they can be bought in thicknesses so they don't need stacked. Yes they will cost 5 bucks each.
I get mine at a local precision fastener company.. (Think head bolt washers, aircraft suppliers... )
their thickness consistency is questionable and they don't look like they are lining up so their hole is bigger than the bolt.
You should use hardened machinists washers that fit the bolts, and they can be bought in thicknesses so they don't need stacked. Yes they will cost 5 bucks each.
I get mine at a local precision fastener company.. (Think head bolt washers, aircraft suppliers... )
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If you have grade 8 bolts holding the converter on, then the spacer material under the converter should be grade 8, those look like home depot imported galvanized washers.
their thickness consistency is questionable and they don't look like they are lining up so their hole is bigger than the bolt.
You should use hardened machinists washers that fit the bolts, and they can be bought in thicknesses so they don't need stacked. Yes they will cost 5 bucks each.
I get mine at a local precision fastener company.. (Think head bolt washers, aircraft suppliers... )
their thickness consistency is questionable and they don't look like they are lining up so their hole is bigger than the bolt.
You should use hardened machinists washers that fit the bolts, and they can be bought in thicknesses so they don't need stacked. Yes they will cost 5 bucks each.
I get mine at a local precision fastener company.. (Think head bolt washers, aircraft suppliers... )
On The Tree
Joined: Jan 2023
Posts: 144
Likes: 54
It wouldn't still knock with the converter unbolted as the OP has stated that he's done.
If you have grade 8 bolts holding the converter on, then the spacer material under the converter should be grade 8, those look like home depot imported galvanized washers.
their thickness consistency is questionable and they don't look like they are lining up so their hole is bigger than the bolt.
You should use hardened machinists washers that fit the bolts, and they can be bought in thicknesses so they don't need stacked. Yes they will cost 5 bucks each.
I get mine at a local precision fastener company.. (Think head bolt washers, aircraft suppliers... )
their thickness consistency is questionable and they don't look like they are lining up so their hole is bigger than the bolt.
You should use hardened machinists washers that fit the bolts, and they can be bought in thicknesses so they don't need stacked. Yes they will cost 5 bucks each.
I get mine at a local precision fastener company.. (Think head bolt washers, aircraft suppliers... )
Launching!
Joined: Oct 2022
Posts: 206
Likes: 74
From: FL
A friend of mine didn't clean the crank after machining a while ago. It had a knock, one of the bearings had around .010 clearance presumably from garbage washing out of the journals. Replaced the bearings with it in the truck and the problem went away. No spun bearings.
The fast paced knock its making is why i think its a bent rod and the skirt it contacting the counter weight. Usually is its a rod bearing knocking like that, it won't knock very bad at idle or revving (unless its really realy bad, and in that case, the thing should have seized by now) but when you put it under a load, it'll knock even more. With a bent rod OR a top ring land busted, the intensity will not usually change under load. Yes a busted top ring land will sound like this too. I know from personal experience.
It's not SBE, it has good parts in it. But I suppose a rod could still get bent.
When I look at that crusty rusted flexplate I just get suspicious.
Fun to guess though, which is what we all are doing. :-)
Have to see what he finds out!
Ron
When I look at that crusty rusted flexplate I just get suspicious.
Fun to guess though, which is what we all are doing. :-)
Have to see what he finds out!
Ron
Thread Starter
Teching In
Joined: Aug 2005
Posts: 30
Likes: 2
From: Asheboro NC
Sorry guys been busy with the kids sports and not much garage time. I got the trans out. Flexplate looked fine. Same noise when running. Pulling the heads this week to check valve train. There was also a different tune put in the car at the time of the converter install. Could be a burnt piston. I'll update as I can. Thanks for the info.