Foxbody 5.0 Coolant Leak Resolution

[WILLIAM MACOMSON]

I have slow coolant leak on a 1987 Mustang GT, which has proved hard to locate. I do not have a pressure test unit personally, which might be the solution. The leak appears to be coming from the front of the engine, around the timing chain cover area. I can never see the leak while the car is running, a small coolant puddle will form under the car after setting overnight. I would like to fix the issue myself, but do not want to randomly replace gaskets in an attempt to fix the problem. The car is supercarged, but not driven extremely hard. There is no evidence of coolant in the oil (or oil in the coolant), air bubbles in the radiator, or water coming out of the exhaust pipes. What has been the most common coolant leak issues on the Foxbody era mustangs for owners in the past? Any suggestions or help on this problem would be appreciated. Thanks!

 

[90sickfox]

Front timing cover gaskets are known to leak, water pump bolts are also known to seep. Thermostat housings are another one.

 

[MustangIIMatt]

Go to Autzone/Advance/O'Reilly and get their loaner cooling system pressure tester. Let the car cool off, top off the radiator, and connect the tester and pressurize it to the PSI rating of the cap (16psi if I'm remembering right). The leak will show up 90% or more of the time using that method. You'll have to put down a deposit on the tester, but it's a good tool, and you get the deposit back when you return it.

 

[Redfire Fox]

I had a leak in the front of the motor while my car sat for a few days. It was coming from the lower intake manifold. Changed it to a better gasket. Went from cork to felpro rubber gasket fixed it.

Now my timing cover is leaking just a little bit. Using a cheap paper gasket to seal water is a horrible idea. I got to pull the harmonic balancer to get to it makes the job intimidating since I never done it before.

 

[7-UP BILL]

My pass side HG is leaking now. Also supercharged and I use Loc-wire gaskets. Went 23 years before any leaks. It's at the front of the engine also. Was a bitch to find, but used the pressure testing method and low and behold, there was the leak. Kinda more like a gusher, but I digress. Pressure test for accurate results.

 

[imp]

Very tiny leaks which occur only when at heat and pressure often "leak" in the form of vapor only. Hot engine all over, the vapor does not always condense back to liquid right on the spot, but disappears into the air. Some leaks stop when the engine parts cool back off. Those are the difficult ones. Pressure test cold and rather hot are both good ideas. imp

 

[WILLIAM MACOMSON]

Thanks for the feedback, I appreciate your time!

 

[WILLIAM MACOMSON]

Thank you for your reply, I wasn't aware of the loan a tool option. I will check with my local store tomorrow, that was very helpful. Thanks for your time and feedback!