Ford Mustang Forums banner

Strange Coolant Leak at Timing Cover

1 reading
7.4K views 4 replies 3 participants last post by  90trunk  
#1 ·
Hi,

I've got a blown 93 GT that started leaking coolant (very slowly) a few years ago.

Strangest part is, it leaks most at cold startup, once the thermostat opens the coolant leak slows or stops completely.

Coolant pools on the timing cover, right above the passenger side coolant passage through it. Thought at first it was the thermostat housing, but after ruling that out, I pulled the alternator/smog pump away and could actually see it seeping from the joint between the timing cover and the block, right on top of the coolant passage through the timing cover......without the motor running.

So I pulled everything apart, cleaned it spotlessly, washed down with brake cleans repeatedly, used gasket sealant on the new Fel Pro gaskets, re-assembled everything to torque spec and filled the system. No leaks while not running, but on first start up.....the pool re-appeared! (I did check the timing cover out carefully and couldn't observe any issues with it....crack, pinholes, score marks, etc...)
I've been driving it for 1 week like this now and it's not losing a lot of coolant, but I can still see the pool after a short drive. I have tried torquing the two bolts surrounding this passage to 25 ft.lbs instead of the recommended 15 ft.lbs and that didn't seem to stop it. Only odd thing there, is that when re-torquing them this morning, they moved before tightening up again.....is that just gasket compression or is something else happening?

Suggestions and Ideas welcome, experience with the issue and resolution is the preference.

Pics attached for your review...

Thanks all,
Nick
 

Attachments

#2 ·
Update: Went for a 20 minute drive, came home, still leaking, while hot grabbed the torque wrench....easily did 1.5 turns per bolt....still not at 25 ftlbs....stopped torquing for fear I'm wrecking something.

Wondering if the bolts are somehow finished....I cleaned them all up when I had them out, while not new, they certainly seemed ok. Should I grab the LMR ARP bolts?

Thanks,
Nick
 
#5 ·
Buy a Mityvac MV4560 cooling system pressure test kit and look for the leak. I had a small puddle forming on top of the timing cover and couldn't pinpoint the source. Withing a minute of pressurizing the system with the Mityvac the source of the leak revealed. It was the intake gasket on the driver's side. The modestly priced tool ($45.00 on Amazon) saved me from misdiagnosing the source and doing unnecessary work.