hemi_fan

I am working on a LM7 Swap into a 91 Volvo 240. When I fire it up there are loud noises that seem to come from the bottom of the engine/flywheel area. It flanks like there are rocks in the oil pan. It also will fall on its face and not go above 4000ish when revved.

It is a stock LM7 with stock 2001 silverado harness and ECU connected to a 4l60e. It does not have the O2 sensors hooked up but otherwise it should be functional (emissions also removed).

Anybody recognise this noise? Sounds pretty bad. I'm guessing it'll have to come back out for a tear down. It does not seem to be exhaust banging against something, but rather something internal. Clanging quiets down/goes away when revved or under load.

VIDEO:

jimmyp3353

iTrader: (3)

I would inspect the flexplate first. Sounds almost like a broken flexplate.

cookseyb

The reason it won't rev is this noise is picked up by the knock sensors and the computer is pulling timing, sounds like the exhaust rattle and maybe the flex plate with those goofy GM fasteners isn't tight

hemi_fan

Thanks for the tips. Hopefully you guys are right. I have to pull the oil pan off anyway as it is only about 2" off the ground and will rub under moderate braking :/ so I'll take a look at the flex plate then.

Suncc49

flexplate / torque converter bolts first check

also wow... you are going to lose that oil pan fast lol

jimmyp3353

iTrader: (3)

If you are using the truck pan right now I would ditch it and get an f-body oil pan. Truck pan is 8.25" deep as opposed to the f-body which is 5" deep. See the link.

https://ls1tech.com/forums/conversio...-oil-pans.html

Taxman20

iTrader: (11)

Id suspect the flexplate is broken or you have flexplate bolts coming out. Could also be the converter bolts are loose.

hemi_fan

I found a used Holley LS swap pan so when that shows up I'll check out the tc and flexplate

hemi_fan

I pulled the trans yesterday. You guys have a good ear. Flex plate bolts were loose. I guess that's what I get for assuming they were tight on a junkyard engine. Now I can fix the atf leak while I'm at it

Taxman20

iTrader: (11)

Cool deal on a cheap fix.

Paul Bell

iTrader: (9)

While you're in there, pop in a new engine rear crank seal.