heat cuts out --brrrr!

horatio324 · 12-19-2006, 05:26 PM

Hi all...

Noticed the other day while driving my heat suddenly went from nice and toasty hot to luke warm for a few minutes, then back to nice and hot for a few minutes... and it's been doing it since. It's a 97 ford explorer 4x4 xlt, pretty good condition, have had all the usual services done on it. I checked the radiator fluid level, it's OK, and it was flushed about... mmm 1 or 2 years ago.

I'm completely automotive ignorant... could this be... a plugged line? Thermostat? Water pump? I did notice the tempature gauge is slightly higher than normal, but still within normal limits. I do plan on taking it into a repair shop shortly, but was wondering before hand what it might be so that I don't get "mislead". Thanks!

--aaron

**Midnight Tech** · 12-19-2006, 06:12 PM

Sounds like either a vacuum motor gone wonky or...wait...does it have automatic temperature control?

horatio324 · 12-19-2006, 10:19 PM

MT,

Does not have automatic temp control. Thanks!
--aaron

**mrbizness1** · 12-23-2006, 08:41 PM

You might have air in the system or a partially blocked heater core.
There are two heater hoses going to the core, they go through the firewall.
When the heat is blowing cold feel the hoses, if one it a lot hotter than the other than you have a circulation problem. You can park the car facing uphill with the radiator cap open and run the motor at increased idle looking for air bubbles near the radiator top (the motor must be fully warmed up). If the hoses are still different than remove the heater hoses and use a hose to force water through the core both ways, this should clear it. Do not pull the hoses off with much force, slit them with a razor blade. You don't want to put to much stress on the heater core. After the hoses are put back on then run the motor with the cap off until warmed up.

12-19-2006, 05:26 PM	#1 (permalink)
horatio324 Registered User Join Date: Dec 2006 Location: susanville ca Posts: 12 OS: XP Home, Pro, SBS 2003	heat cuts out --brrrr! Hi all... Noticed the other day while driving my heat suddenly went from nice and toasty hot to luke warm for a few minutes, then back to nice and hot for a few minutes... and it's been doing it since. It's a 97 ford explorer 4x4 xlt, pretty good condition, have had all the usual services done on it. I checked the radiator fluid level, it's OK, and it was flushed about... mmm 1 or 2 years ago. I'm completely automotive ignorant... could this be... a plugged line? Thermostat? Water pump? I did notice the tempature gauge is slightly higher than normal, but still within normal limits. I do plan on taking it into a repair shop shortly, but was wondering before hand what it might be so that I don't get "mislead". Thanks! --aaron

12-19-2006, 06:12 PM	#2 (permalink)
Midnight Tech Admin/Head GreaseMonkey/Igor's alter ego/Grand Exalted PoohBah Join Date: Dec 2001 Location: SC Posts: 2,920 OS: Windows XP Home/Pro SP3/Windows 98SE/Fedora Core 6/RH 7.2 with Autopoint/TAMS II	Sounds like either a vacuum motor gone wonky or...wait...does it have automatic temperature control? __________________ Please post all questions in the appropriate forum. Questions sent by email or PM will not be answered. Sharing my life...with my Imzadi! Interested in Trek gaming? Check out the Dynaverse! Proud supporter of the Carolinas Aviation Museum. If we have helped you in any way, please donate to keep TSF up and running!

12-19-2006, 10:19 PM	#3 (permalink)
horatio324 Registered User Join Date: Dec 2006 Location: susanville ca Posts: 12 OS: XP Home, Pro, SBS 2003	MT, Does not have automatic temp control. Thanks! --aaron

12-23-2006, 08:41 PM	#4 (permalink)
mrbizness1 I helped the forums. Join Date: Dec 2004 Location: Mt. Sinai NY Posts: 76 OS: win xp pro	You might have air in the system or a partially blocked heater core. There are two heater hoses going to the core, they go through the firewall. When the heat is blowing cold feel the hoses, if one it a lot hotter than the other than you have a circulation problem. You can park the car facing uphill with the radiator cap open and run the motor at increased idle looking for air bubbles near the radiator top (the motor must be fully warmed up). If the hoses are still different than remove the heater hoses and use a hose to force water through the core both ways, this should clear it. Do not pull the hoses off with much force, slit them with a razor blade. You don't want to put to much stress on the heater core. After the hoses are put back on then run the motor with the cap off until warmed up.