Erik T

guys,

hope you can help me out on this one:
over the last months I changed cylinderhead, belts etc.
After that engine was cranking but did not start, problem was in the sensor area. Last week when I was working on the sensor issue and cranking the car to check Voltage the engine suddenly got stuck. First I thought it was the starter engine but now it appears to be the crankshaft is stuck!!

What could be the problem here? Could it be a stuck piston? (lack of oil maybe).

Before I start stripping the engine again... HELP!

Bones944

It may be a hydraulic lock with unburnt fuel in the cylinders, remove your plugs and see if it will turn.

Erik T

removed sparkplugs, nothing changes.. I read something about ATF fluid for stuck pistons, is it working.

FYI: because of the non-firing I cranked the car many times without it having running, could this cause a lack of oil between piston and wall?

Erik T

of course I ment to ask if ATF fluid could be helpful to loosen up pistons..

nine-44

Usually ATF is good for the pistons, I don't know if it would save the cylinder walls? They are coated. It kinda sounds like maybe a valve hitting the piston? I doubt that it would get hot enough to lock without firing. These cars get oil pressure pretty quick when cranking, I don't really think they would be dry? Good luck man!

SoCal Driver

If you can't turn the engine either way with a socket on the front crank bolt then the crank has seized up. If there is a bit of free play in the crank then a piston has seized up.

CT944

Remove the plugs and put a little oil in each cyl, every day, rotate the crankbolt 1/2 to 1 inch until it becomes free (back and forth). this is a tedious task, but it should work. take your time, little by little. i've got many motors out of the "sieze" stage wit this method. you still will have some motor problems though. good luck!

Erik T

Hi CT,

can I use regular engine oil for this task? You scared me with your last sentence... "you still will have some motor problems though".. please clarify

SoCal: how can the cranckshaft sieze up?

thanks so far guys!

emilysgranny

I think So Cal's tip is the key give away here. Remove the plugs ,and try to spin the engine backwards with a breaker bar on the crank bolt. If it moves , chances are there is a dropped valve , keeper may have come loose, Or the belt jumped timing. If it doesn't move backwards you have a major internal engine problem.

Tom M'Guinn

I'd first check to see if all the roller are still torqued and the belt is still tensioned. Then I'd pull the starter to make sure it did not seize by overheating when you were cranking it. I can't imagine you siezed the motor via oil starvation cranking it to start, although stranger things have happened I guess. Were the valves/head done by a reputable shop? Was the cam tower seated right on reassembly (any big leaks)?

emilysgranny

Tom brings a valid point here, if you can turn the engine by breaker bar , then it could be as simple as a burned out starter from cranking to long , (generally the internal solenoid button connector )or an overheated wire from a heavy draw causing a bad connection. I hope it is as simple as this .

CT944

If you can't turn the engine with a breaker bar, taking out the starter would be my next check, as said above, maybe the starter is frozen on the flywheel. Try that first.

After you check the above methods mentioned, yes you can use regular motor oil (thin as possible).

Geo

Isn't the trick of oil or ATF in the bores for blocks with cast iron cylinders with rings rusted to the bores?

If the pistons themselves are seized in the bores the engine is in need of a total rebuild. There is bound to be galling between the pistons and the bores.

Geo

Oh, and I don't really see any way for the crank to seize. We're talking forged steel vs brass (the bearing base metal). No contest.

cruise98

Erik:

Maybe the sensor has been jammed into the ring gear or the stud. This would lock up the crank. Pull the sensors and try to turn the crank with a breaker bar.

Good luck.