No heat, then heat

2005X · 10-17-2008, 06:00 PM

jeep has 13,000 miles on it, last night driving around and the air was coming out cold, also had a faint burning smell. well this morning i go and and check, yup i have hot air, and the smell is gone. i need ideas or suggestions to look for

**Rocky529** · 10-17-2008, 06:37 PM

You could have a vacuum leak that is preventing the blend door from fully opening allowing heat to come out of your vents. The reason you checked it this morning and it was working is because the motor's vacuum is strongest at idle. Try driving it around and see if the heat disappears again.

If it does, check all the vacuum line connections in the engine bay.. especially the 'T' at the passenger side of the firewall where the heater hoses connect to the heater core.

Tim · 10-17-2008, 07:38 PM

your coolant could be low
your water pump may be going bad

johnnn · 10-17-2008, 08:22 PM

Not too late for warranty work I hope.

The vacuum hoses shouldn't be leaking, but a short piece of garden hose for a hearing aid might help hear the sucking sound of a leak.

You might get a check engine code.

I'd check the radiator level first. You might have smelled aintifreeze on an exhaust pipe.

LJameson · 10-17-2008, 08:25 PM

For the burning smell...is this the first time you've used it in a while? I know my TJ does make a faint burning smell the first time it gets cold for the season.

2005X · 10-17-2008, 09:55 PM

as far as warranty, ive had my jeep 3 years as of last week!
levels are all good
this is first time for heat this year
my jeep was muddy from the last wheeling trip so i drive it to the local carwash with no doors or top on, i sprayed everything down, seats, inside windshield, if it was exposed it got washed, so the drive home i never noticed the heat being so cold out i couldnt have felt it anyways with all the wind from driving. it wasnt until i pulled into the garage that i realized that cold air was coming out, and that faint smell.
i decided to go ahead and drive it around town tonight, the heat was so hot i had to turn it off. everything is working as if there were no issue??

willness33 · 10-18-2008, 12:45 AM

Quote:

Originally Posted by 2005X

as far as warranty, ive had my jeep 3 years as of last week!
levels are all good
this is first time for heat this year
my jeep was muddy from the last wheeling trip so i drive it to the local carwash with no doors or top on, i sprayed everything down, seats, inside windshield, if it was exposed it got washed, so the drive home i never noticed the heat being so cold out i couldnt have felt it anyways with all the wind from driving. it wasnt until i pulled into the garage that i realized that cold air was coming out, and that faint smell.
i decided to go ahead and drive it around town tonight, the heat was so hot i had to turn it off. everything is working as if there were no issue??

IF the engine temp went up when the heat stopped working, change the t-stat.