Vintage Mustang Forums banner

1 - 2 of 2 Posts

·
Registered
Joined
·
304 Posts
Discussion Starter #1
I posted a couple of weeks about the problem I was having with overheating at idle and the garage doing the restore was trying everything non-invasive engine-wise to fix the problem (new radiator, larger fan, shroud, propylene glycol antifreeze, engine flush) but nothing helped. Well it seems the engine had a partially blown head gasket. How partial vs full works I don't know especially since we didn't see any of the symptoms of a blown head gasket.

Keeping with the suggestion of doing a search (aka RTFM), here's what I dug up on the web for newbies like myself.

There are any number of things that'll happen when your blow a head gasket.

Common symptoms:
- Foaming, bubbling, or "gargling" in the radiator.
- Rapid pressure buildup in your cooling system, before the engine has warmed up.
- Some have even reported coolant overflowing from the reservoir bottle because of the pressure.

All these above mentioned symptoms could also be a cracked head. Either way, the head must come off, the gasket replaced, and the head inspected for cracks. At the same time, check both mating surfaces for flatness before putting on a new gasket so you don't have to repeat the job.

Other symptoms of a blown head gasket include:
- White smoke coming from the tailpipe, sometimes intermittently.
- Water in the oil. When they mix, the oil gets a chocolate milkshake appearance.
- Oil in the coolant.
- Cylinder pressure low when using either the wet or dry compression method.
- Cooling system will not hold pressure when statically pressurized.
 

·
Registered
Joined
·
313 Posts
I had trouble with head gaskets on a 351W. The gaskets didn't leak any water into the engine and it ran fine because there was no leakage between cylinders. It ran OK at idle and slow speed cruising, but hit the highway and it would run out of water in a few miles.

After teardown and inspection it appeared that on the 2 rear cylinders, compression gases were blowing into the water jackets. This served to force water out of the system through the overflow. It probably didn't help that the heads had been milled way beyond what any reasonable person would have done!
 
1 - 2 of 2 Posts
Top