Slow crank

[N1ffer]

Hello all,

Having issues with a 1992 Sunbird. 4.3L with Cobra outdrive.

I had an overheating issue that I thought I caught quickly without damage. Once the engine cooled down and tried to start it was basically just getting a click at the starter and a very slight movement of the crank, but no turn over cranking.

Hooked up the jump box and was getting about 12.4 volts and still the same, a slight (barely noticeable) turn of the crank and a click at the starter.

Put a socket and breaker bar on the crank bolt and the engine turned over without much effort.

Got towed home, hooked up the 200 amp jump starter at 13.4v and basically the same thing. Was able to turn the crank fine with the breaker bar/socket.

Took it to a shop. They ordered a new starter, installed and got the same issue. Bought another starter just in case and same thing.

Shop says it needs a rebuild or a new engine. I am perplexed. Could an over heat cause this? The temp gauge was high, but never hit above the green "safe" area. Was literally on the water less than a quarter of a mile. Smelled the engine and stopped right away. Then poured water over the block to get it to cool faster so it didn't stay hot for a long time causing more damage.

Any thoughts what could be going on here? Thanks in advance.

Todd

 

[Bondo]

Ayuh,..... Welcome Aboard,..... I'd start by pullin, 'n cleanin' both ends of both battery cables to clean shiny metal clean, 'n try it,.....
If that don't work, use a set of jumper cables to by-pass the battery cables,....
I suspect corrosion is the problem,......
Cleanin' the connections eliminates the connections,.....
Usin' jumper cables can tell ya whether the cables have internal corrosion inside the cable's coverings,....

 

[Scott Danforth]

Clean the battery terminals as indicated

Find a different shop

Never turn a Chevrolet motor over by the crank bolt

 

[kenny nunez]

Take the spark plugs out and see if it turns with the starter.

 

[hugh g]

Never pour cold water on a hot engine to cool it off.

 

[N1ffer]

Clean the battery terminals as indicated

Find a different shop

Never turn a Chevrolet motor over by the crank bolt

Has dual batteries. The engine started just fine 5 minutes before it overheated. Had nearly 14 volts at the gauge. Not thinking it is that. Why would you not turn a chevy motor with the crank bolt. How else would you check to see if the engine was locked?

 

[Scott Danforth]

Has dual batteries. The engine started just fine 5 minutes before it overheated. Had nearly 14 volts at the gauge. Not thinking it is that. Why would you not turn a chevy motor with the crank bolt. How else would you check to see if the engine was locked?

because you will strip the bolt thread out of the crank and need a new crank.

get one of these if you want to turn the motor over by the crank. https://www.amazon.com/Crankshaft-Turning-Socket-Chevy-4-Cylinder/dp/B001U3V334/

or pull the starter and pry over by the flywheel teeth.

battery voltage means nothing if your connections are corroded.

 

[PITBoat]

Yeah, I was wondering about the crank bolt thing myself, as I was using that to try to position the distributor properly for points gap check a while (year or 2) back (with plugs removed, of course).

Now I know.

I plan to use the dwell angle method now, so... no prob.

I wish I knew more about the Chevy motors, by experience.

 

[kenny nunez]

To set the dwell I do it with the plugs out and the coil wire grounded. I also like to set the timing with the spark plugs on the wires but grounded on the manifold. That way you do not have to keep starting the engine.