Have recently found an 03 that got hot and blew the HG. The seller said he thought it had a cracked block but he didn't know for sure. He owned it a total of 3 days before it went bad.

I have an extra motor so either way it works for me but I would like to change out the HG if that is all. How would I verify no crack in block without pulling the motor?

Other than that it was a north florida truck with little rust on frame, silver, and real nice. Got it for 25 ounces of silver.

 

Where did the HG blow? Externally?

If so then you can top off the fluids and run it for a short time up to temp... Then shut it down and look into each cylinder with a boroscope for signs of coolant bubbling around the seam where the head joins the block on the inner four cylinders without nearby water jackets.

If it won't run then you could probably do that with a coolant system pressurizer pumped up to 18 pounds and of course with the coolant filled and bled so that there was enough to seep through any cracks.

 

There is no real way to tell.
It is more likely bad head gaskets than a cracked block, but the block is still a possibility.

 

But, if the block is cracked, coolant is going to leak around the top and bottom of the liner.
With the bore scope, you may see coolant or bubbles around the head gasket, head to block surface. But that could be leaking past the gasket, or up past the liner, leaking into the cylinder in the same location.

 

Cracks usually don't give symptoms until the engine is very hot. As sixpack said, no real way to test. A good indicator is checking the piston heads to see if any look "steam cleaned". Also, coolant in the oil could indicate the water jacket got compromised and coolant is leaking in the cylinder bore and into the crankcase.

Check out JE Robison Service | Service, repair and restoration of fine motor cars articles for more good info.

 

You could just have a blown head gasket or a cracked head. It's not always a cracked block.

Your machine shop can pressure test your heads after you've removed them for the head gasket job, and you'll want the machine shop to mill the heads for the new head gasket job, anyway, so it's a two-fer.

 

Mine has a cracked block, blows white smoke out of number 6, on fb Land Rover forum they called it and were right. Basically if it blows white smoke out of the middle cylinders probably a cracked blocked.