5.3 swap starter clunking noise when cranking...

[bs46488]

Needs some advice on a LS swap (not on a C10, put in a Big Block). This swap is in a 1970 Nova.

So Sunday was the official day to start the car. Everything is done, no leaks, fuel pump relay seems to be working correctly, I even ran exhaust on the car.

Decided to crank the engine over (pulled the fuel pump relay for a no start situation) to see what the mechanical oil pressure gauge would do and ran into 2 problems:

1) There is a nasty clunking noise when the starter cranks. Inside the car it feels bad, it sounds like a loud clunk almost like the driveshaft is hitting the floor pan (its not moving, I checked). Outside the car, it does not sound as bad. It just sounds like the starter is not meshing correctly or engaging enough, or maybe just hitting he flywheel.

2) I didn't crank a lot because of issue #1, but I didn't see any movement on the oil pressure gauge

Looking for suggestions on issue #1.

A little of the background: 2002 Silverado 5.3 with 4l60E (supposed to have 87k on it). Got the engine, trans, wire harness and ecu as a pull out. Didn't separate the engine and trans. I only removed the starter to put in the new Holley oil pan, then bolted it back in place. Used the LT1swap.com for harness modification and he flashed my ecu.

I'm running a battery in the back with 1/0 welding wire, using a ford starter solenoid in the trunk and have a little jumper wire from the battery lead to the "S" start wire on the starter. Brand new battery. Battery is grounded in the trunk to the body. Engine has 3 grounds up front from the block to the body and chassis.

[BR3W CITY]

Whack the crap out of the starter with a rubber mallet or a piece of wood. Your starter might not be fully disengaging and catching teeth on the flywheel....that can go realllllly bad. Also, because the starter bolts next to/into the oil pan, you might want to verify that you don't need to add a spacer to any of the starter bolts. The pan may have changed the starters position in reference to the flywheel.

If its a mechanical OP gauge, you won't see oil pressure until the oil gets all the way up the line and into the gauge. You won't have that level of oil movement during a few 5-7 second starter bumps. Mine registered 0 on the gauge and over 50 when it actually started.

Might not hurt to check that all the flywheel bolts are tight. If one is backed out, it can whack stuff and make all sorts of scary noises. Whatever it is, the engine will PROBABLY detect it as knock, and will pull timing until its fixed.

[ls1nova71]

Check your flexplate and make sure there are no missing teeth, I had one with a missing tooth that would make a terrible clunking noise.

[bs46488]

Quick update:

Hooked up a battery in the engine compartment (to eliminate trunk mounted battery) - no change

Pulled the starter, the teeth I saw on the fly wheel looked good. But didn't check the whole thing.

Hooked the starter up to some jumper cables to trip the solenoid. Hit it 12-15 times. 1-2 times it worked normal. 5-6 times it went, but didn't retract. 5-6 times it freaked out and plunged in and out while spinning. A couple of times it spun, but didn't move.

Sounds like I need a starter....

[bs46488]

Update:

Ended up putting in a starter and it made no change.

Checked the flywheel and all teeth present and accounted for.

Decided to just pull the trigger and see what happens.

It fired right up. No crazy noises and oil pressure jumped up about 3-5 seconds after start.

Guess I'm officially and LS swap project now!