heater question...

[rcarchie]

my heat is not very warm even when on high fan speed and full temperature setting......the thermostat seems to be working OK...the engine warms up gradually to operating temps within about 5-10 mins after start up....the collant level is good......I checked it when the Jeep is cold and the level is to the brim of the radiator fill neck...the inlet and outlet hoses to the heater core are warm and about the same temp.....the fan works well in all 3 speeds......could the core just be old and not able to pick up the heat from the warm coolant as it circulates through it?.....any other ideas why I can only get luke warm air from the heater?.....thanks..

[steeve555]

Heater core.

[steeve555]

Heater core. Replace fan while your at it. It will be out anyways. Not expensive.

[rcarchie]

thanks steeve555.....that was what i was thinking aabout doing....i have been reading about the Blazer motor upgrade....i was just hoping i could get my existing sytem to work OK to save me the time and $....

[Hunter]

Before you spend any $ on it, flush out the core you have and it may be fine.

With the engine off, in the engine compartment, find the two hoses on the passenger side of the firewall. Trace the lines to see which is in and which is the out hose from the core. Remove the hoses and induce water from a garden hose into the "out" side of the core. This back flushes all of the crud from the core back out the "in" side and onto the ground. When the water runs clear, reconnect the hoses.

I did it a couple of years ago and it instantally went from barely warm to real heat.

[Varnish]

-=- originally posted by rcarchie -=-
thanks steeve555.....that was what i was thinking aabout doing....i have been reading about the Blazer motor upgrade....i was just hoping i could get my existing sytem to work OK to save me the time and $....

fyi, i just replaced my 88yj blower motor with what was specified by napa as the replacement motor and it ended up being a larger diameter and required cutting the firewall. the blower through quadratec seems to call for this too. not sure how this larger blower compares to the stock sized blower as i hadn't used my old one long but the new YJ replacement seems fine power wise.

[rcarchie]

thanks varnish.....i have done a lot of reading up on the blower motor upgrade and core replacement and everything i have read agrees with what you are saying that the firewall hole will have to be enlarged.....i also read several posts where the owner simply tried to replace the blower motor with a stock unit and also had to enlarge the hole.....from what i have read, the biggest thing to be aware of is to be sure you get the larger motor with the right length fan shaft....some of the motor shafts are too long which causes the fan to hit the side of the housing when you try to put everything back together.....i sent an e-mail to one of the authors of the better internet posts i read and he gave me the exact part number for the blower motor i need that has the righ length shaft......looks like i have an interesting and 'fun' w/e coming up soon....

[rcarchie]

Hunter, i will definetly try the back flushing of the core......i always change my coolant every year anyway, so now is a good time to do the backflush......thanks for the tip.....

[emyselfandi]

-=- originally posted by rcarchie -=-
Hunter, i will definetly try the back flushing of the core......i always change my coolant every year anyway, so now is a good time to do the backflush......thanks for the tip.....

x2 on the flush... after I replaced my old ass rad the heater and engine temp took forever to heat up. I think I had an air pocket in the head so after that got fixed the fan still didn't put out hot air. I pulled the hoses off and poored in some flush stuff. Let is sit for a couple minutes and then flushed it out. There was so much build up that came out it surprised me. Got it all back together and now it works 100% better. If you want to spend the 100 bucks or so on a new core and fan go for it but i'd rather buy a skid or something and just flush it. :beerchug:

[rcarchie]

trust me, i don't want to spend the $100 or the time to replace the core and fan....it really doesn't get that cold here in SC, at least not for any length of time.....if I can get the stock system to put out hot air that's the way i'll go.......any recommendations as to what brand of radiator flush works the best?

[emyselfandi]

any brand i think they are all pretty much the same.. T

[Hunter]

rcarchie,
You will not need to buy any radiator flush, nor will you need to flush, drain or loose coolant. When the engine is off and cool, you can remove the hoses to the core on the firewall side, maybe only loosing a minimal amount or fluid that may be in the hose.

When you back flush it, just use regular water from the garden hose. It will reverse flush the heater core only. When the water coming out of the core is as clean as what is going in, shut it off and hook the heater core hoses back up. The flushing only takes a minute or two.

[rcarchie]

thanks Hunter....i just bought the Jeep a few months ago so i don't know how old the coolant is......i will probably use this opportunity to go ahead and flush out the entire system and put new coolant in....just as a safety precaution.....i just got through changing out all of the drive line fluids.....the brake system is next!