Trying to manually turn engine over Tahoe 5.7 1999

[ScottyBoy]

Hopefully this isn't your problem, but my mom had a Chevy Astro van with the same symptoms as you. We thought the starter was bad, so we bought a new starter. Same thing, just one clunk when turning the key, then nothing. Also, the engine quit running on her one day and we never could get it to turn over after that. Tried turning the crank pulley with a breaker bar but it wouldn't budge. Every mechanic we talked to said it was highly likely that the engine had catastrophic internal damage, especially since one minute it was running fine then all of a sudden it seized up.
So we ended up getting it rebuilt. Sure enough, the crankshaft was cracked in two. The fuel spider injector was also found to be leaking gas in the intake, and it was getting in the oil.

 

[JohnDoe]

Thanks y'all.

Any idea what type of penetrating oil I should use in pistons?

John

 

[ExEvolution]

When your starter hits, does it crank, or is it just a loud click? If its the latter, it might be poor connection with the battery. My yukon would have this issue if the bolt wasn't completely tightened, where the starter would make a single loud click when I turned the key, but would not crank. I changed out the bolt in the wire harness for a longer bolt, and padded it with washers and it completely fixed my problem

 

[JohnDoe]

Hi Ex,

I'll check that this weekend too.

Thanks

John

 

[JohnDoe]

ok well I tried the socket on the alternator and camshaft no dice. I didnt use too much pressure. I put wd-40 in each spark plug hole to maybe loosen the piston rings. Ill let that soak til this weekend.

I dont have the transmissionl cover off. It only looks like about 6 bolts to take it off and then ill need a flywheel tool.

John

 

[retorq]

If you can't turn it over with a flywheel tool it's locked. You might be able to get a loaner from Autozone ...

 

[JohnDoe]

Called Autozone today they said rebuilt engine is 1569.00 from Surefire. So is taking the engine out easy? Just need need to mark and remove wires and remove some bolts on tranny remove hood and lift engine out with engine hoist? Put engine on on flatbed trailer haul it to Autozone swap engines with Autozone and install parts in reverse order?

One thing Autozone said was that that the 1997 Tahoe 5.7 had a notoriously bad crankshaft sensor which was causing timing errors causing crankshafts to break along with a host of other problems.

Didn't have time to remove starter this weekend, but I will and then I will try putting it in neutral and turning engine.

I did put WD40 in each cylinder by removing spark plugs then let them soak all last week and tried to start it normally - same thud! each time with no revolution of the engine at all.


John

 

[DustinMcGee]

Called Autozone today they said rebuilt engine is 1569.00 from Surefire. So is taking the engine out easy? Just need need to mark and remove wires and remove some bolts on tranny remove hood and lift engine out with engine hoist? Put engine on on flatbed trailer haul it to Autozone swap engines with Autozone and install parts in reverse order?

One thing Autozone said was that that the 1997 Tahoe 5.7 had a notoriously bad crankshaft sensor which was causing timing errors causing crankshafts to break along with a host of other problems.

Didn't have time to remove starter this weekend, but I will and then I will try putting it in neutral and turning engine.

I did put WD40 in each cylinder by removing spark plugs then let them soak all last week and tried to start it normally - same thud! each time with no revolution of the engine at all.


John

Ever figure this out? Same deal on my 02 Tahoe 5.3