Leaking thermostat and boiling reservoir

ford
mustang

#1

I have a 98 mustang. It has been having best issues for a while and a boiling reservoir. The thermostat is brand new as I replaced it last night. Car ran fine this morning but it overheated when I got off work and was driving home. The reservoir has a hole in the top corner of it and may have something to do with it, and the thermostat has leaked some liquid. I couldn’t see the color so I’m not sure what liquid it could be. What could be causing this? Also has a new radiator and I’m not sure if the fan even turns on. I haven’t checked that.


#2

If the cooling system has a leak, it can’t hold pressure. And the engine can overheat.

Tester


#3

Tester has provided the answer for the OP.


#4

Im not sure where the leak could be though. I replaced the thermostat last night and its now leaking. It hasn’t leaked much, but it didn’t leak with the old one but does with the new one.


#5

That’s where the coolant leak is.

Tester


#6

Do you have the V6 (unpressurized reservoir):
MustangV6

Or the V8 (pressurized reservoir)?:
MustangV8


#7

I have the v6


#8

“Boiling” in an unpressurized reservoir is many times caused by a blown head gasket. Try a new radiator cap…and pray…

;-]


#9

I presume you mean the thermostat housing is leaking. When you buy a replacement thermostat, you also have to buy a new gasket that fits the housing. The gasket doesn’t come with the thermostat automatically. Did you do that?