91 Camaro RS 5.0 TBI. Bought the car about a month ago, had block sealer in it when I bought it

Since then I have replaced the water pump due to a horribly bad bearing, flushed the coolant probably 6 times to get the block sealer out, replaced the thermostat with a 195 degree/OEM temp stat, and replaced the intake gasket, which was what the cheap P/O was trying to fix with block sealer. Heater control valve looks to be fairly recent as well.

Since it's been in my possession, the heat only gets hot when the coolant temp gauge gets up to around 220, which it only does while sitting in bumper to bumper traffic. When moving, the heat is lukewarm even on the hottest setting.

Any ideas? I'm thinking clogged heater core from the block sealer at this point. Is it worth trying to flush, or should I just replace it?

 

Pretty tough to flush those... takes many times the amount of water that you can get out of a garden hose, to really do a completely effective job.

You could try back-flushing it though, after all ya got nothing to lose by trying... force water into the ¾" (cold return) port, watch for schmutz coming out of the 5/8" (hot supply) one

 

Get a different fan switch to turn the fan on earlier. Stock fan wont even turn on until 230ish that's always seemed a lil high for me also. If your car has double fans(which I'm scared it may not) turn the a/c on in traffic and both fans will come on and you will probably be good.

 

Wouldnt that be counter effective.Try runnung water thru the heater core to see if any comes out the other "outlet".Should tell you if its blocked.

 

The fan motor may be getting tired, and not flowing enough air. A common problem.


..my apologies...I completely misread the problem. Sorry!

 

I have had a lot of luck flushing heater cores with a garden hose. I usually clamp on a cut hose to the heater core output or the output hose then put the other side in a bucket. I have flushed a lot of radiator sealer that way. My brother put that stuff in his 4.3L jimmy. After changing the radiator, hoses, pump and gaskets everything was good for about a week the the extra stuff that I could not flush out wound up in the heater core and had to back flush that. then everything was good.

 

Well that gives me some hope. Will give that a go next week once it warms up here...in the meantime, my trips are short, and I have plenty of warm clothes to pile on. Thanks!