No real heat even after flushing?

[BlackPearl]

So the 2000 TA was pumping out no heat anymore. Has been like this for awhile but it was summer so I didn't pay it any mind. This past week, it reminded me, needed fixed.

I changed the leaky water pump. Used a valvoline product to flush it out initially as a complete system then flushed out the block, radiator and heater core all separately. Then reflushed a few times to the point where it was clear water coming out.

Started it up and heat jumped up to about 120 degree's while parked with a thermometer stuck in the dash vent. COOL!

Went for a drive and the heat dropped to barely lukewarm.

WTH? Are the radiators that efficient in these when they are moving? Is there something I missed?

[5150]

Did you recheck your coolant level to make sure there were no air bubbles in the system? I also believe there is an off on valve actuated by vacuum inline with the heater hose. Is it functioning properly? Just some guesses.

[0rion]

could also be a t-stat that's stuck open or a partially clogged heater core. Like 5150 said though....first thing is to make sure you've purged all the air out of the system. Best way to do that is to run it with the radiator cap off until the t-stat opens and cycles water through the block. This will also tell you if the t-stat is stuck open. If you start it and water is immediately circulating through the radiator then you know the stat is open. That vac line that 5150 mentioned I *believe* is for the controls only so if your vents are switching you can rule that out. Last would be a clogged heater core. Normally those will crack and you'll smell antifreeze in the car but I've had them just plug up. I've had luck in the past back flushing a heater core but it's usually only a temporary fix.

[BlackPearl]

The thermostat is new. I verified it is working as it should

Backflushed the heater core twice.

No anitfreeze smell anywhere.

I will open the rad cap again, I have heard that these cars take a little while to get the air out, not sure if its true or not.

Its comfortable inside with the heat its blowing, but compared to my F150 and 4runner, it is definitely not at the same level of output. I had also heard these cars don't get terribly warm in cold weather. any truth to that?

Thanks guys!

[5150]

I've got a 160 thermostat in mine and it blows hot air. Does your gauge temp show any movement when the heater starts to blow cooler air? I know the factory temp gauges aren't to accurate but if it did I would definitely be leaning towards air in the system.

[cammed goat]

Keep us posted.

[2002ssslp]

This may be a stupid question but what is the condition of your heater hoses. Sometimes, when they get old and soft, under pressure they can "suck shut" and cutoff your heat. Just something to check.

[moesplace]

check your air blend door it control by a small motor from ac control that mix the air from heater core & ac when it hot hold one of lines going to core if it hot you have flow had problem with GM trucks with ac control