Heating core question?

[Buckeye Hummer]

What are the possible solutions to the occasional loss of heat? The truck is fully warmed up and after 30 minutes (sometimes) no heat at all. Other days, no problems. I've heard something about a water valve.

Thanks for any help.

[Buckeye Hummer]

What are the possible solutions to the occasional loss of heat? The truck is fully warmed up and after 30 minutes (sometimes) no heat at all. Other days, no problems. I've heard something about a water valve.

Thanks for any help.

[DRTYFN]

I'm noticing the same thing on the '00 Soft-top that I've got for a loaner right now.
It seems to take forever to blow hot air even after it reaches normal operating temp.

S&B Member since '03

[Buckeye Hummer]

Someone said something about a water valve but I need to figure what the hell I need to do with it. I don't like going to the dealer for simple crap.

[ssgharkness020147]

The water valve is not opening and closing all the way, assuming that it is your water valve. Whatever it is having a new truck you should take it to the dealer, it will be fixed for free as oposed to you doing it yourself, then you will have to pay for the parts.

Carey Harkness
1998 HMCO

[Beefcake255]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Buckeye Hummer:
What are the possible solutions to the occasional loss of heat? The truck is fully warmed up and after 30 minutes (sometimes) no heat at all. Other days, no problems. I've heard something about a water valve.

Thanks for any help.<HR></BLOCKQUOTE>

I've noticed similar issues with cold air seeping out occassionally.... I thought it may have started after the installation of my air intake (Air Force One) and thought there may be a connection between the two... but now I'm not so sure??? Any ideas besides a water/coolant valve sticking????

[Buckeye Hummer]

It turned out to be the water valve. Very simple, 5 minute fix. The kids love the fact that I have heat now!

[JSA_3]

Thanks for letting us know. Can you elaborate? Did you fix it yourself, or have your dealer fix it. Was it expensive? (I know you're still under warranty, so am I, I'm just curioius)

I only ask because my heat is marginal at best. If it's below 30 outside and the truck is warm, the air will go cold at red lights, and warm back up with the engine under load. (I've checked water level, and it is fine) I also notice if I have the dash vents selected they seem to blow warmer air than the floor vents. Maybe a valve not gone, but going?

Thanks,
John

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'02 HMCO

[Buckeye Hummer]

I took it to Cerritos. There is a guy named Mike there that races for Hummer and knows everything there is to know. I just drove it in without an appointment and he stopped everything and fixed it.

He took the rubber piping off from the fan to access the water valve, which I believe sits rather low inside the compartment. He basically just unstuck it. I'm not sure if he lubed it somehow but there was nothing to replace. 5 minutes tops and now I have hot air. You probably have the same problem so either try it yourself or let them deal with it.

[JSA_3]

Thanks tons - - sounds easy enough, definitely something to check out.

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'02 HMCO

[ssgharkness020147]

John next time you are at a stoplight watch you temp gauge. If cools down then goes back up when you subject the engine to load it is probally your thermostats not your water valve. Go to www.amghummer.com (http://www.amghummer.com) for the procedure on how to change them. As for you question of how much a new water valve will cost, 314.00.

Carey Harkness
1998 HMCO

[Axleman]

Yet another explanation... one which I am intimately familiar with this week http://www.elcova.com/infopop/emoticons/icon_frown.gif

Bad head gasket/cracked head. Exhaust gasses enter the cooling passages and get trapped in the heater core. No hot water in heater core = heater not workey. These gasses moving through the system will also cause fluctuations in the temp gauge. If you are mysteriously loosing coolant as well, this may be the problem. Hopefully most of you just have heater valve issues.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & Steering (http://www.southernaxle.com)Remanufactured Driveline & Steering Parts for Hummers

[ssgharkness020147]

And if a cracked head or head gasket is the problem it only gets better, then you need to find out if you have a cracked block. http://www.elcova.com/infopop/emoticons/icon_frown.gif

Carey Harkness
1998 HMCO

[JSA_3]

Thanks guys for all the possibilities. I'm going to have it checked out.

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'02 HMCO