Coolant leak

[Flip Smiley]

I have a small coolant leak that forms on the rear oil pan lip and runs down and drips from the engine side of the bell housing cover plate. Of course I’m having a difficult time determining the origin of the leak. I suspected and replaced the intake manifold gaskets. The leak persists. I now think it must be the head gaskets. Before I tear it down and replace them I would like to hear some opinions from some seasoned Ford mechanics. This is a 1990 5.0 from a Mustang with around a 100k miles. I don’t have heater tubes, hoses or other coolant associated items near the rear of the engine. I have checked to make sure the water pump and other items on the front of the engine are tight. I know if they leak the fluid can travel on the oil pan flange and gravitate to the back of the engine. I also have checked and confirmed that none of casting plugs have failed. Should I replace the head gaskets?
Thanks for your considerations, Flip

[edwardb]

I wouldn't jump to head gaskets quite yet. As you said, fluid can be coming from most anywhere and travel to other places. I've had similar scares myself and often found a connecter or whatever far away from where the fluid was dripping. If unable to trace it, I'd get some UV die and trace it that way. Has worked for me.

[Norm B]

Check your lower head bolts. They go through into the coolant passage in the block. Maybe one of them isn't sealed properly.

Norm

[egchewy79]

consider getting a coolant system pressure tester. you can "rent" these for free at some local auto shops. I got mine from Napa. they hook up to the filler cap and allow you to pressurize to a selected PSI. I would then sit and listen for a hiss or look all over for any drips. I found a very slow leak from my water pump heater hose nipple that needed to be removed and replaced.

[Flip Smiley]

OK, thanks for your input. I’ll spend some more time investigating before jumping into head gasket replacement.
Flip

[J R Jones]

consider getting a coolant system pressure tester. you can "rent" these for free at some local auto shops. I got mine from Napa. they hook up to the filler cap and allow you to pressurize to a selected PSI. I would then sit and listen for a hiss or look all over for any drips. I found a very slow leak from my water pump heater hose nipple that needed to be removed and replaced.

I have blown shop air pressure into the filler neck overflow hose to pressurize the cooling system to the cap pressure for troubleshooting.
jim

[BEAR-AvHistory]

Don't want to waste your time but had the same end result a puddle under the bellhousing. Turned out to be the right front coupling for the heater hose to the engine. Water was migrating from there to the back of the engine before it started down to the floor.

[J R Jones]

BEAR, "before it started down to the floor."
Thankfully trousers dry-out quickly in dry weather.
jim

[Fman]

Another option is to visit your local auto parts store (O'Reilly, Autozone, Napa) and rent a pressure tester for the coolant system. You can pressurize 16-20 psi directly from the cap which will reveal where the leak is. I have used one before to test for a bad head gasket, they work good and most of the parts store will let you have them for a free rental with a credit card as security deposit.