Why the crap is my Heater Not working????

[YosemiteMatt]

1989 XJ. No heat. Thermostat is only reading 150 tops. Why won't this dang heater get hot? Thermostat will fluctuate randomly between 210 and 150. Daaaang its cold! All fluids are full. :anon: Clueless.

 

[in4aride]

check it with something besides your dash guage-mine is roughly 5-8* off of actual temp....

mine had been running super cold too and was a failed tstat that wouldnt let it warm up... now even with the good working tstat it takes a bit to warm up with the super cold temps....
check your tstat and make sure coolant is still good and doesnt need a change....




let the arguing begin

 

[YosemiteMatt]

Let's throw it all out there. I also have a radiator leak, which I make it a point to fill the reservoir once every to other week or so. I've never replaced the thermostat. Last week I replaced my HVAC system. I know that this is a closed system...so would that make the temp be off because the fluid leakes? Could it be a HVAC problem with the vacuum system maybe???

 

[old_man]

I have found over the years that the most common thing causing lack of heat is a heater valve that either isn't being activated (lack of vacuum/bad switch) or a bad valve. Other than that, it normally is a plugged heater core if there is zero heat coming out.

View the position of the lever on the heater valve with the engine off for a few minutes. Then start up the engine and put the controls to heat. You should see that the lever has moved. If it has not, grab a pair of pliers and see if you can actuate the valve manually. If you can, rig it to stay in that position with a tiewrap or some safety wire (redneck bailing wire).

 

[old_man]

Even with a fubar'd tstat you will still get some heat.

 

[Frank Z]

Time to upgrade to an open cooling system. I've got a used 2 row from my 97 sitting in the garage gathering dust.
$50 an it's yours.

 

[DutchVDub]

Yes, on a closed system a leak will cause issues.

By hvac system what do you mean exactly? Heater core? Blower motor?

If your engine doesn't get up to temp then obviously you're heater won't work worth a damn either as your coolant provides the heat. T-stat is a cheap/easy thing to do that most of the time fixes the problem and if it doesn't you're only out like 12$

 

[YosemiteMatt]

HVAC: meaning the control panel for my AC/Heather controls.
I'm do for a new radiator because mine is $ to expensive to keep filling up. Any advice or threads on what I need to convert over to "open system"? I live in OK at the moment of otherwise I'd pick up the radiator from FrankZ. I'll need to go hit up the bone yard for the right stuff...

I'm not sure which heater valve you may be referring to not opening. Are you talking about the one located under and near the reservoir tank?

 

[old_man]

Mine is just in front of the firewall on the passenger's side and has two hoses running through the firewall.

 

[Hypoid]

I'm not sure which heater valve you may be referring to not opening. Are you talking about the one located under and near the reservoir tank?

Yes

 

[YosemiteMatt]

Time to upgrade to an open cooling system. I've got a used 2 row from my 97 sitting in the garage gathering dust.
$50 an it's yours.

Will a 1997 2 row work in my 1989? Does anyone have a good thread for doing this? If not I'll try and make one.

 

[Frank Z]

There have been a lot write-up's on closed to open conversions. And yes the radiator will fit.

 

[YosemiteMatt]

Thanks Frank Z. Any one have a strong opinion either way on this. I'm thinking closed just because I only have to swap in a new radiator and burp the system. The new is new and I don't have to burp the system.