Heater core

[gonzo596]

Can I backflush my heatercore with water if it's below freezing out?

[98FloridaXJ]

How cold? I'd think if it was below 32 but above zero you could work quickly enough to flush, remove and refill with coolant.

[4.3LXJ]

If it is 30° out, OK. But below that you might risk freezing water in the tubes and not accomplish what you wanted. You could try warming up the engine and heater core first, and particularly the cabin. Then you would be OK

[gonzo596]

Thanks guys for the response I'll hope for a warmer day before I start on it

[Gravedigger]

not sure if this would be to hot to do on to cold of a day but maybe hook your garden hose up to the water heater in your house.i do that to was my girls pool with hot water.

i have never tryed this on a back flush on a cold day.so use caution.

[bluedragon436]

Hoping to get a warm day here, so I can do the same with my 97 I just picked up.. She def doesn't have any heat, and it won't be good if we have snow.. at least I have my truck I can drive and it has beautiful heat.. I ran back flush on my heater core with my 98.. I took and ran both directions then I poured some CLR in the core and let it set for a few minutes.. then flushed it with water... and low pressure air .. was some real nasty looking stuff came out of it.. I can only imagine what'll come out of 97's core..

[WhiteDevil1311]

Backflush above freezing. I did this on my s10 4x4 in feb of 2004. Mar 2004 i was replacing the HC. If you can backflush and use antifreeze to "rinse" (reclaim the antifreeze into a bottle) you wont freeze. I learned tricks after that cruddy day in 04

[gonzo596]

Thanks again everyone!!! Seeing that its 3 degrees here in Michigan i won't be trying it for a while

[WhiteDevil1311]

-3 here in chiraq. Enjoy the warmth

[TSquared42]

Hoping to get a warm day here, so I can do the same with my 97 I just picked up.. She def doesn't have any heat, and it won't be good if we have snow.. at least I have my truck I can drive and it has beautiful heat.. I ran back flush on my heater core with my 98.. I took and ran both directions then I poured some CLR in the core and let it set for a few minutes.. then flushed it with water... and low pressure air .. was some real nasty looking stuff came out of it.. I can only imagine what'll come out of 97's core..
When I bought my Jeep there didn't seem to be any heat. I checked the thermostate and it was acutally broken. ~$10 to fix this as its right in front of the engine block.