jimonlight

Gentlemen and ladies, Jim here. Lifetime tinkerer, DIY guy, concert lighting dude. My Mustang is a silver 2010 V6 4.0L, plain jane silver, black interior, I love my girl.

I drive the mustang also for business trips, and this last one from Memphis to Oklahoma City I was driving home late at night and the engine kicked into overheat mode, I pulled over and found a coolant leak. Looked like it was from where the thermostat body is, so I filled the reclaim tank, and got her home.

I'm a child of an engineer, and I grew up working on my own cars, and I quite enjoy it, but this one is stumping me, and money is tight as heck so I'm trying to fix this so I can keep working... I've replaced the water pump myself, thermostat, and I thought I had it solved! Nope, my last business drive from OKC to Dallas, coolant leak, same spot -- right at the assembly where the thermostat lives.

I've taken a video if that will help -- unlisted YT link:

Would I be right in assuming that I have a leak in the thermostat housing itself and that I can replace it? It seems like once I drained the cooling system and re-tightened the thermostat housing, it might have postponed the leak somewhat, but when she got back hot again, leak. It's just a constant weep that is getting considerably worse, right around where that housing is, and I have got to fix this **** in order to work!

I've got all day tomorrow to fix this thang, I've got an Autozone, O'Reilly, Pep Boys, AND anything else within ten minutes of me. What do you guys think?



New pump installed!



I personally think the cooling channel is beautiful...



Artistic photo of the work

Any thoughts are appreciated!

Jim

jimonlight

Hey, just as a warning, I said the F word in this video, I initially sent it to my dad, so my intended audience was my fleet retired Navy engineer dad. Sorry ahead of time if anyone is slightly offended...

JimC

The thermostat housing is a common failure point on the 4.0. Easy to replace, and quite often misdiagnosed as a faulty water pump because of how the coolant runs down. You can get an aluminum one off Amazon, quite a bit more but not prone to failure.

JJHoover

there are 3 freeze plugs under the intake. I just recently replaced mine and originally thought it was the thermostat housing. do a pressure test and see if its coming from under the intake.

07 Stang

Keep us updated on what you find.