new truck = problems
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Junior User
Joined: Jun 2006
Posts: 51
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From: Malmo Ne
new truck = problems
New truck is a 91 F-250 4X4 7.3L Reg cab long box.
We bought it for a 1000 dollars and he said the motor was locked up so we trailered home and I have 92 with a motor that did run before we got it.
But I threw in a pair of batteries and tried cranking motor just incase something changed. And the motor turned a little and turned right back after you got off of the starter. So my question is whats wrong can a locked motor move at all or did water or someting get into one of the combustion chambers and does not let it turn over. It rained last night and I have a little water around what I think is #3 cylinder on the drivers side of motor. could there be water in a cylinder or is motor toast.
We bought it for a 1000 dollars and he said the motor was locked up so we trailered home and I have 92 with a motor that did run before we got it.
But I threw in a pair of batteries and tried cranking motor just incase something changed. And the motor turned a little and turned right back after you got off of the starter. So my question is whats wrong can a locked motor move at all or did water or someting get into one of the combustion chambers and does not let it turn over. It rained last night and I have a little water around what I think is #3 cylinder on the drivers side of motor. could there be water in a cylinder or is motor toast.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
Was there coolant in the motor?
Was the coolant level low?
Hydrolock is what happens when a fluid is in the cylinder.
Fluids do not compress.
Off the top of my head there is only about 24cc's of room left when the piston is at TDC on a 7.3 engine.
So it don't take much fluid to lock a motor up.
Remove the glow plugs from all the cylinders and try turning the engine over by hand.
If you can get a complete rotation, run the starter and crank it over a couple more revolutions to blow the fluid out of all the cylinders.
Rain water should not be able to enter the cylinders if the air cleaner is in place unless it has been modified.
Coolant in the cylinders could be from,
A blown head gasket
Cavitiation
Cracked block
Cracked head
Drivers side cylinders are from front to back 2,4,6,and 8.
And I have seen a motor that was hydrolocked one day, start and run the next day.
The coolant drained into the oil pan over night so the hydrolock was gone the next day.
As to the engine being trash, that depends on where the problem is and how much water is in the oil pan or the rest of the motor.
Was the coolant level low?
Hydrolock is what happens when a fluid is in the cylinder.
Fluids do not compress.
Off the top of my head there is only about 24cc's of room left when the piston is at TDC on a 7.3 engine.
So it don't take much fluid to lock a motor up.
Remove the glow plugs from all the cylinders and try turning the engine over by hand.
If you can get a complete rotation, run the starter and crank it over a couple more revolutions to blow the fluid out of all the cylinders.
Rain water should not be able to enter the cylinders if the air cleaner is in place unless it has been modified.
Coolant in the cylinders could be from,
A blown head gasket
Cavitiation
Cracked block
Cracked head
Drivers side cylinders are from front to back 2,4,6,and 8.
And I have seen a motor that was hydrolocked one day, start and run the next day.
The coolant drained into the oil pan over night so the hydrolock was gone the next day.
As to the engine being trash, that depends on where the problem is and how much water is in the oil pan or the rest of the motor.
Junior User
Joined: Jun 2006
Posts: 88
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From: Victoria B.C
Originally Posted by ford-diesel-91
The motor will not turn over with a 3/4 inch drive wratchet and reducer and impact socket. It will only move a little about 3/8 to a 1/2 inch forward or backwards.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
For it to only move that small amount, you must have problems in more than one cylinder.
If it won't move with the glow plugs out, the problem is mechanical like broken valve heads between the pistons and head or a broken connecting rod.
If it won't move with the glow plugs in, the problem may be water in more than one cylinder.
If it won't move with the glow plugs out, the problem is mechanical like broken valve heads between the pistons and head or a broken connecting rod.
If it won't move with the glow plugs in, the problem may be water in more than one cylinder.
