I have a 95 acclaim. I have barely any hot air (heat defrost vent doesn't matter). Car is at normal temp. I'm guessing my heater core is plugged. Just had a new water pump installed with the timing belt and coolant flushed when this was done. (1k miles ago). Anything else it could be other then plugged core?

 

It might be or it could be the blend door (the flap that blocks hot or cold air depending on temp setting) is stuck in the cold air position. I cant remember if they are vacuum or cable operated. if they are cable, move the temp selector and listen if you hear any sounds from behind the dash the doesnt have to be running. It would help if you could look under the dash while doing this. If its vac operated, start the engine and do the same steps. Let me know what you find and I'll try to walk you through next step.

 

I checked the blend door. I can hear it move as i slide the control. I can feel a difference in temp of the air when I do. It just doesn't get hot like it did last year.

 

When you had the pump and flush done was the t-stat replaced? If you had a 190 degree t-stat and it was replaced with a 160 degree you will feel a difference in how hot the heat gets. With a 160 the t-stat will open at 160 degrees and flow through the cooling system and heater core, a 190 opens at 190 degrees.

 

Its possible you could have some air in the system. I think when you change the thermostat you are supposed to bleed the system via a bleeder valve near the thermostat housing. It also possible that you are getting air in the system from a very small head gasket leak. Does the antifreeze look clean or dirty. I had one 93 Acclaim 2.5 l with a very small head gasket leak which seemed to affect the heater as you describe.

 

Good call on the air bound system. Most auto parts stores have the kit to bleed out the air, it simply consists of a funnel, and radiator cap with a hole to insert the funnel. It is simple to use, we use these at the shop all the time. Open the cap and replace with the one in the kit and insert the funnel and fill the funnel, run the car with the heat on but not the blower. As the coolant circulates it will draw in the coolant in the funnel and expel the air. I would advise not using the bleeder, I have seen so many break on older cars, they can be a p.i.t.a. to replace at that point. Once the the coolant in the funnel gets hot and stops bubbling the air should be gone.

 

My 94 Acclaim with the 3.0L had that problem and I flushed the coolant system and it works great now. I have never seen a 2.5L or 3.0L that needed burped. Anything is possible, but I've just owned a bunch of both and never seen it.

 

Yes it was bled with the special cap and a 190 t stat was put back in. The previous owner never did any maintenance, leaving me with the resulting problems. This is why I was thinking there could have been enough junk in the system to plug the core.

 

I flushed out the heater core and it flows fine and clean. What's my next thing to do?

 

The next step is to burp the system with a 50/50 mix. This needs to be done because the system was opened. Remember when you burp it make sure the temp control is set to heat, the blower is off, and the vents are on (no defroster). Let it idle for a few minutes and periodically bring the idle up to about 2k for a minute. until the coolant in the funnel stops bubbling.