Alright, I've had a few posts about an odor of coolant for a few weeks now, havent had the time to get it into a shop, or time for that....so today driveing around, the service engine soon light pops, on yea 1st time since getting the blazer, then after a few minutes with that on, my heat dies, its slightly warm but nothing like normal... in 10*-20* weather......I noticed after the blazer was parked for maybe an hour then driveing again my temp guage stayed really low, climbed slightly but not at the normal running temp. I then parked it on a Hill, back of truck towards bottom of hill, and when i backed off of the hill, heat worked almost normal....so my 1st question is are the service engine soon light and the heat issue possibly related???? or just coincidence it happened at the same time....2nd I read about heater core flushings could that possibly help? or is there something more likely wrong....so far no coolant on passenger floor area.....and no real lost of coolant.....this is just a bad time of yr to be haveing issues, just spent most of my $ on x-mas gifts.....guess some are going back.....

 

when your heat started working again, did the engine temp go up? i would say that problem is probably due to thermostat getting stuck open, then freeing itself up and closing. i wouldnt say that problem is related to your service engine soon light. your heater not being hot would be related to your t-stat being stuck open and your engine temp dropping. i would say if it does it again, replace yout t-stat. as far as the service engine light. if you have an auto parts store around, go there and have them scan it. i know auto zone will do it, im not positive about and other store though.

 

Sounds like the t-stat is stuck in the open position. To replace is simple and cost less than $20 if you do the work yourself. Basically need some sockets and wrenches and time. You have to remove a couple of nuts from the front of the TB for the throttle cable bracket, to move it out of the way and then you need a socket for the two nuts on the t-stat housing. You can drain the coolant to a level where you won't leak any fluids but when I replaced mine there was very little to leak so I just left that alone and removed the t-stat housing pulled out the t-stat, put in the new one with the rubber o-ring around it as the gasket. The replaced the t-stat housing, bolted it down to specs 13ft/lbs or snug plus a quarter turn, does not have to be super tight. Then put back the throttle cable braket on the TB tighten them also to 13ft/lbs. Fill the radiator full of coolant, start the engine check that t-stat is working refill if needed.

 

Well wanted to give an update, On my way to get a new thermostat my heat came back but I changed the thermostat anyways, so heat works now, and driveing to work today my service engine soon light shut off..so now guess I gotta wait and see what happens now...thanks for the tips...