Leaky Head Gasket

Bud

Well-known member
General question: If a car has been sitting a while (I don't know how long, maybe a year) with a leaky head gasket, what possible damage could that have done to the engine? The engine was not filled with water but anti-freeze.
 
General question: If a car has been sitting a while (I don't know how long, maybe a year) with a leaky head gasket, what possible damage could that have done to the engine? The engine was not filled with water but anti-freeze.


If enough leaked into the cylinders, antifreeze may have gotten into motor oil. Drain/change oil before running the motor. Antifreeze is worse than water for Babbitts and bearings in general. Since the Babbitts are not sealed bearings, they are the most susceptible. Additionally you may want to pull the oil pan to clean the pan and the dipper tray to get all of the oil/antifreeze out of the motor. If you flush it out before running the motor not much chance that I know of would be damaged. Then if you want to run it use water for testing, and get the gasket changed as soon as possible.


Not sure if there are other issues.


If it was water, depending on how long it sat, you could have rust which can cause more issues.
 
it can wipe out your cylinders. and the antifreeze will eat up your bearings. that was one of the first lessons I learned the hard way years ago on a motor with only 700 miles on it, it was a .040 over now it is a .060 over. if your head is leaking on the outside chances are it is leaking inside to.
 
it can wipe out your cylinders. and the antifreeze will eat up your bearings. that was one of the first lessons I learned the hard way years ago on a motor with only 700 miles on it, it was a .040 over now it is a .060 over. if your head is leaking on the outside chances are it is leaking inside to.


Was it just sitting, or did you run it once it leaked? Thought I read somewhere the antifreeze damage occurs primarily when the motor is running. Either way probably best to pull the head and look before running the motor.
 
If the anti-freeze was going to rust something, then it would do same to the inside of the cast iron block.
 
I can't answer most of your questions, it happened to a friends car and I was not there when he replaced the head gasket.
 
I just replaced a head gasket where coolant was leaking into a cylinder, but I do not use anti-freeze. However, gasket leaks are generally small, and over time just the coolant above the gasket will leak. My engine sat for about 6 months.



In all of my 58 years of playing with car engines, I have never seen anti-freeze harm a bearing, be it babbitt or aluminum. However, I do know that spent anti-freeze turns acidic, so it is possible but not common place that anti-freeze gets into bearings and destroys them.



It has been my observation that a coolant leak into a long period dormant engine cylinder may cause some surface rusting of the cylinder walls, and in an extreme case, some pitting of the cylinder walls.



1. Pull all of the sparks out;
2. Using a flashlight, look into the spark plug holes and see which cylinders are wet with coolant;
3. Put about 1/2-cup of liquid lubricant in each cylinder;
4. With the gasoline OFF and ignition OFF, hand-crank the engine. If a cylinder has a significant amount of coolant in it, the coolant will pump out thru its spark plug hole;
5. Replace the head gasket;
6. Change the crankcase oil;
7. Take the car for a ride long enough to get engine up to operating temperature;
8. Re-torque the cylinder head nuts;
9. For peace of mind, do a compression test.
 
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