Hey guys & gals.

I have a coolant leak problem with my 2008 Hummer H3 5cyl LUX edition 147k miles.

Been noticing the temp level has been hanging around 3/4 hot all summer long on drives. The I started having a small leak coming from the firewall petcock underneath the 2 heater hoses. <PLEASE SEE PICK> I didn't think much of it, always just refilled the tank weekly until today. Today it became a lot worse and it emptied the coolant tank on a 10 mile trip. As I was pulling into to the driveway the "Engine Hot" & "AC OFF" alarm both displayed on the DIC and I pulled her in and topped of the coolant tank. But the problem keeps happening after 1 mile of driving now.

I'm disabled and I do not have much money due to my fixed income. Hopefully one of you has had this issue and will help me out. I don't have money to start aimlessly throwing money at the water pump, thermostat, cracked block/head or heater core and not have a def answer of what's wrong? I need a 1 shot fix.

What would make the coolant come out that overflow on the firewall? Is it my heater core? My pass floor is a little wet but you can't smell coolant so I thought it was just wet shoes, until now I just dunno...

Please Help & Thank You
Jeff Blanchard

 

Funny Hummerz!

That doesn't help me tho, but funny!!!

I've been searching threads for coolant leaks other than the radiators n moonroofs, all I can find is to check my oil n tranny fluid, I did both and they are both fine.

 

That petcock you are pointing to is the AC condenser drain tube - it is not connected to your engine cooling system.

You are refilling the coolant reservoir tank weekly? If you don't see puddles or smell coolant from the engine bay, I'd say it must be going thru the engine block or head.

 

Check that liquid with your nose or tongue, coolant has a sweet taste.

 

Does it smoke from the tail pipe? Does it smell like coolant while driving as in a pinhole in the radiator?

Do you know how to tell if water is in your Transmission Fluid and/or motor oil?

Take it to a radiator shop if you are unable to do a pressure test. Not something to play with, you could have a coolant leak into the transmission or blown head gasket allowing coolant into the motor oil. Both/either can be catastrophic leading to major repair/replacement costs.

 

if coolant is draining out of that spigot then your heater core has a hole in it. if you do not use heat then bypass it with a double hose barb. replacing the heater core is a hell of a job need to pull the black box hummerz posted out from inside the dash.

 

Wife had to use it today she only drives 1 mile to work. I'm 100% sure the ac hole in the firewall is where its leaking from cause I've seen it, touched it, and its antifreeze.
I did feel the carpet and its wet on the passenger side. It's probably heater core. It doesnt smoke out the tailpipe, nor leak anywhere else.

I appreciate the replies guys!!! I'm gunna have the local repair man take a look at the h3. It's all above what I can physically do. The heatercore black box is the size of the whole damm dashboard!!!

I did the one in my 99 silverado and the whole dashboard had to be unbolted n pushed aside... huge job cost $1100

Thanks again guys and I will post the final results once I get them!!!

 

Usually when it is the heater core you can smell the coolant inside. If it leaked on the floor, check to see if that has coolant by soaking it up with a white cloth..... if it turns pink, you know it is the core. Replacing a heater core really sucks.

Good luck.

 

$1100 for a heater core replacement DIY? You must be from the south!

 

Dang, if it takes that much work for a heater core, I'd just call the car totaled

What was wrong with putting them on the bottom and making them easily accessible for replacement, like they used to be?