What do you do if your car engine is frozen?

Answer 1

There are many factors as to why an engine 'freezes'. Typically, if the engine was stored outside or had an opening for water to enter (removed spark plugs, incorrectly routed exhaust) then water was allowed into the cylinders and the rings rusted to the cylinder walls. If the engine was 'run dry' then replace the term rusted with 'welded' There are, of course, many other components that my be involved as well.

First, verify there is no mechanical interference from some external component. Sometimes on Chevy/GM engines, the starter would engage with the flywheel and get stuck, so make sure your external components all move freely and operate correctly.

Next, remove the spark plugs and spray a shot of WD40 or engine oil into each cylinder. DON'T OVER DO IT! A little goes a long way. Attach a breaker bar with a socket onto the crankshaft bolt (a large size bolt typically located in the middle of the harmonic balancer/pulleys) and attempt to turn the motor in the clockwise rotation (some engines do rotate counter-clockwise so verify this first). DON'T FORCE IT! With the plugs removed the engine will be easier to turn over if it's going to. Using too much force will bend or break parts.

If the engine will not turn, start rotating the engine back an forth slowly, applying a little more force each time. Again, don't over do it. Once the engine start to turn, focus your effort on rotating the engine in the correct direction. Engines don't like it when they go backwards so keep your momentum moving in the correct direction.

Once/If the engine starts to rotate go slow and easy for the first few rotations. Add a little more oil to the cylinders and to the valve train as you go. Spend some time here making 10 to 20 complete revolutions by hand. Remove the valve covers and verify everything is moving freely and looks correct.

If this works, reconnect the starting components but not the ignition components (make sure the ignition is properly disabled) and see if the engine will rotate freely on the starter. If it does, replace the ignition and all other remaining components and fire it it! NO HARD REV'S, DON'T PUT A LOAD ON IT! Just let it idle for a bit. Shut the engine off, and change the oil and filter again. Look for signs of metal, babbitt and water.

Go easy on it for the first 10 to 20 miles. If it sounds good and is running decent, you're got to go.

Some obvious steps and tips;

1. If you ran it dry, fill it back up before you try this and find out why it was empty.

2. Disconnect the battery.

3. Remove the breaker bar before you attempt to start the engine.

4. If possible, remove the oil pan and valve covers for inspection and cleaning.

5. Use an engine "tank style" block heater above 1000w to heat the engine prior to attempting this. Do not attempt this if the temperature is anywhere near freezing. If possible, get a block heater with a 165 degree or hotter thermostat. This will make your life easier by a whole bunch!

6. Use your eyes, ears and nose to troubleshoot the obvious. The engine will probable make some noise when it starts but should go away quickly if the engine is still sound.

7. Remove as much from the engine as you feel comfortable with. I always remove the engine covers and (when possible) the engine head(s). A look into the cylinders will tell you pretty quick if the engine can be saved.

8. With run dry engines, galling or metal transfer is your biggest concern. If a piston has transfered aluminum to the cylinder walls then forget trying to save it. No matter how much you can clean up the cylinder it will fail again. Time to rebuild or replace it.

My success rate using the above is about %50 for rusted engine, 10% for run-dry engines.

Good luck.

Answer 2

First get it into a warm place and thaw it out. Then have your cooling system pressure tested to see if you have any internal leaks which would cause damage if you drive the car.