I picked up an 88GXL with 80k on it for nothing with a seized engine. The previous owner said he went down in the morning and it almost started then wouldn't turn over, he then parked it for a year. I, thinking it was carbon locked used Amsoil Power Foam in the plug holes and intake and let it sit for a couple weeks respraying every couple of days. Well today I tried to see if the engine would turn backwards by rolling it forward down the hill in reverse gear and when the clutch was let out it stopped the tires dead (even skidded them). We tried it in forward and reverse a half a dozen times and the engine did not turn. I'm guessing this is more than carbon lock and probably an apex seal lodged somewhere?

Has anyone had one locked up this tight? Any other suggestions before I pull the engine?

Jim

 

Is the actual engine not turn or is it not starting. MY guess is it may have a broken seal or something. If the engine did not turn, there are more problems then carbon lock. haha!
BTW when your in reverse the engine itself does not turn the other direction. It's the trans.

 

Just cause you put the tranny in reverse, doesn't mean the engine will rotate the opposite way. Reverse has an extra gear in it to change the direction of the output shaft.

Take the starter off, and use a screw driver to slowly spin the flywheel. When you are standing at the front bumper looking at the engine, its rotation is clockwise. So from behind the engine, counter clockwise is forward, and clockwise is backwards. You want to turn the flywheel clockwise as you see it from the back. Take the spark plugs out (label them first so you don't get the wires crossed) and put either ATF (automatic tranny fluid) or MMO in the holes to try to break up the carbon. Rotating the engine backwards will move the apex away from the carbon that is blocking it. It acts like a chock in a tire. It blocks the forward path, but since carbon doesn't build up on the back side of the apex, you should be able to rotate it backwards. Carbon builds up because the engine was designed to inject engine oil into the combustion area to lubricate the apex seals. Burning engine oil leaves carbon. Do some research on how to disable the oil injection system and start using 2 stroke oil in the gas tank. It mixes better and was designed to burn cleanly without leaving carbon deposits.

 

OK guys this can't be true. If I put the car in a forward gear and roll the car backwards it would have to turn the engine backwards or counterclockwise; likewise if I put the car in reverse and roll it forward it would do the same thing. Once in gear with the clutch out there is a direct connection between the wheels and the engine so if you move it forward in a reverse gear or backwards in a forward gear it would have to move the engine backwards as well.

 

mans got a point. Tried dumping ATF in there to help dissolve the carbon?

 

No I went with the Amsoil power foam that Atkins Rotary said was the best for carbon lock. At this point it couldn't hurt, I might as well add some ATF to the mix.

 

have you tried a BIG breaker bar and a LONG pipe with the tranny in nuetral? It usually get's V8's that have the pistons welded to the cylinder walls unseized, but doesn't exactly help them out..