Motor freezes up periodically

C

cdubs

Member
What would cause a flathead to run great, and then a day later not even turn over? I can't even turn the engine over by hand... New oil, battery, new wiring, newly rebuilt starter ( which I took out and tested) no overheating.... And then, by some miracle, I'll try and start it another day and it will turn. Very frustrating. Oh, and does anyone know of anyone that can rebuild flatheads in south Florida?

Thanks all
 
Hi there, Maybe hydraulic lock as in water (engine coolant) in one or more cylinders. Leaking cylinder head gasket, cracked head or block. Do a radiator cooling system pressure test to see if it will hold pressure on the tester gauge. Is your engine oil milky, water in the oil. Another test is compressed air into each cylinder spark plug hole with its valves closed and look for air bubbles at radiator filler. Regards, Kevin.
 
I don't know the answer, but I would really try to see if the reason for not turning is a problem with the starter or solenoid or something else on that side, or the big question is, is it not turning because it is stuck solid.

A hydraulic lock would cause that scenario, and would need to be investigated. If when it is not turning, you can't get the crank to move by pushing the car on a flat surface in top gear, then it is stuck. I don't know if it would move at least a little if pushed backwards if hydraulic locked, it's a new one on me.

Next time it is stuck, try moving it in gear, and then try with the spark plugs removed.

You need to try and troubleshoot this in logical steps, and ruling some things out is good because you can home in on the answer.

Good luck, I'll follow this one with interest.

Mart.
 
Take your spark plugs out then try to turn the engine. Have some one look to see if any water/anti-freeze shoots out of a plug hole.
 
Freezing up, I was going to suggest moving to south Florida, so much for that idea. Check the starter, put her in high gear and rock it to dislodge the starter drive, Chuck S.
 
I have had my starter lock up engaged into the engine.
I had to put the transmission in gear and rock the car back and forth and then it pops back in place and everything is fine. Seems to happen when sitting for a month.
The problem is most likely something simple.
As Chuck says.
 
Its well over 40 years ago but I can remember the 46 Ford truck engine "locking up". I had to loosen the bolts holding the starter on. I don't recall taking it right off, just loosened and that was enough to free it up as the gears had jammed. I don't know what vehicle you are talking but it was not a difficult job on the truck from underneath.
 
You guys are the best. Thank you so much for all the replys. I checked the oil and no coolant in it. I took off the starter yesterday and tested it with the battery. It turned over without issue. It has the original solenoid, so I'll be picking up a new one. I'll also check for hydraulic lock. Would hydraulic lock be an issue that occurs periodically?
 
No, it would be a very uncommon thing. It was only mentioned because it is hard to think of a scenario where the motor would be stuck one time and then turning ok the next.

It is quite unlikely that this is the problem, but it can't be ruled out. There would likely be water in the oil so maybe you have ruled it out already.

Having water in the motor is a very bad thing and can even cause bent conrods if not found. You have not indicated whether the motor turns over without using the starter. (other than your original post where you did state the motor wouldn't turn by hand.)

Mart.
 
Pay close attention to gear condition on that starter. And be sure it has the pan bracket to keep it from flexing under torque. If the gear has been damaged by the starter flexing/jamming, it'll be a bit larger project than just solenoid.
 
If the gear on the starter shaft is damaged, I'd bet the ring gear is, too. Most often, a problem is connected to the last thing that was done to the engine. If that includes your "newly rebuilt starter", I agree with the others. If you are using the new style starter drive " ("Bendix"), it may not retract properly. There have been posts regarding that.
 
When I removed the starter, it took some persuading. I had to tap it a couple times with a rubber hammer to get the starter drive assembly to disengage from the engine, and when I did so, the Armature spun clockwise to eventually come off. Is that a sign of something?
 
Do you have the little bracket from the back of the starter to the side of the oil pan? If not, you should!! This is what it prevents!!
 
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