95 blazer heater core or thermostat?

[mat24]

thoughts, my 95 blazer just now gives warm or less than warm heat.
i changed the thermostat, and there is no differance. now shall i turn to the heater core? how can one check if it is bad? or maby the thermostat is not in the right position. fluid is at 25- or better. to change out the core is there a "trick" on doing that easily?
thanks for any thoughts

[DelCoch]

There is no easy way to replace the heater core, unless you want to take a sawsall and cut out the dash. It's a real pain, the dash has to come most of the way out.

What was the temp size of the new thermostat? Should be 190 or 195.

Are you due for a radiator flush?

If the engine temp is getting up to 185-190 at least one of the heater hoses should be hot. When the heater control valve is open, (heater control set to max heat) both heater hoses should be warm; which indicates coolant is flowing through the heater core. If one hose is hot and the other one cool, there’s an obstruction in the heater core; or the control valve is not being opened up or there is an obstruction in the valve, or the valve is defective.

If both hoses don’t get hot I would disconnect both of them at the engine end and with the heater temp control set to max try to run water from a garden hose (at low pressure) into one hose and see what comes out of the other hose. If a lot of crud comes out, get it to run clear and then do a radiator flush. If you can’t flush water through the heater core, on either heater hose, then you’ve found the problem. Sometimes a heater hose will disintegrate on the inside and become blocked. This usually happens near the end of the hose.

Let us know what you find and we can help you further.

[mat24]

thank you i plan to get in to this this weekend
thanks again this gives me a couple more ops

[frehol]

Hi,
Sorry but I don't think there is a trick to change out the core it easily. But second time it took me just half the time compared to the first...
Loosen dash and move it back enough to work behind (or in front of ?) it. I followed Haynes manual, it worked quite well with a -95 like mine.

Before you get in to that job be sure it is the core. Feel the return hose, is it getting warm, I.E. there is flow through the core? Maybe it need a flush?
Or the blend door: is it working?
Does engine temp get up to normal? If not you might be on right track with the T-stat...

Search the forum for how-to...

Good Luck!
//Freddy