Crazy heater

[crobar1]

1996 Caprice Classic 350 the best ever
Last winter 2007/2008 had a new ac compressor installed. Noted after the heater wasn't putting out the usual hot heat. I noted after running the engine up to temp (always cool) the heat output would be a little better. The ac guy said he flushed and relaced the therm. No difference. This summer the ac worked great but this winter I have the same problem. Do you think it just needs a good flush or replacement?

[j cAT]

Originally Posted by crobar1

1996 Caprice Classic 350 the best ever
Last winter 2007/2008 had a new ac compressor installed. Noted after the heater wasn't putting out the usual hot heat. I noted after running the engine up to temp (always cool) the heat output would be a little better. The ac guy said he flushed and relaced the therm. No difference. This summer the ac worked great but this winter I have the same problem. Do you think it just needs a good flush or replacement?

on my 96 impala manual a/c system the heater core back in 98 required the flush then again in 2000. this was because GM sealant tablets where blocking the heater core ...it was visible in the bucket on purging..

since these tablets are now gone your problem is simply a debris build up..the engine should be completely drained if the dexcool is not clean ,...then flush core as described in other post and you should have more heat than you can handle...my 96 runs at 50% temp and its very warm..

[wafrederick]

Reverse the heater hoses and this does work,it takes you about 5 seconds to do.It cleans the heater core out.

[crobar1]

Well I flushed the core and man the gunk came out. I took the plastic pressurized fill tank off and it was loaded. I tried to flush out but I could not desolve the dark gunk like stuff so I had to do the best I could and replace it.
I need help to flush this and radiator or replace the tank if someone can guide me to where I can buy one?

[j cAT]

Originally Posted by crobar1

Well I flushed the core and man the gunk came out. I took the plastic pressurized fill tank off and it was loaded. I tried to flush out but I could not desolve the dark gunk like stuff so I had to do the best I could and replace it.
I need help to flush this and radiator or replace the tank if someone can guide me to where I can buy one?

what coolant are you using? did you drain the engine by removing the knock sensors....

you can use an acid wash to clean out the res tank....remove and block openings continue to shake the res to loosen the crap....rinse thoughly...


dexcool and distilled water you will have no problems like me ....

[crobar1]

Originally Posted by j cAT

what coolant are you using? did you drain the engine by removing the knock sensors....

you can use an acid wash to clean out the res tank....remove and block openings continue to shake the res to loosen the crap....rinse thoughly...


dexcool and distilled water you will have no problems like me ....

Can you recomend an acid wash? As to the knock sensors; are they anti knock sensor? I don't know where they are?
I guess that I need a tech manual can you recomend one?
Working conditions here are a little limited so major mechanical work needs to be thought about as we are 50 miles from town.
If I understand what I'm doing I'll tackle it so I'm gatherering as much info as I can.
Thanks

[j cAT]

Originally Posted by crobar1

Can you recomend an acid wash? As to the knock sensors; are they anti knock sensor? I don't know where they are?
I guess that I need a tech manual can you recomend one?
Working conditions here are a little limited so major mechanical work needs to be thought about as we are 50 miles from town.
If I understand what I'm doing I'll tackle it so I'm gatherering as much info as I can.
Thanks

at your auto supplier they will have this flush chemical kit...remove thermostat before using the flush chemical if you flush the engine..

the knock sensors are on each side of the engine mid point .. a wire is connected to each..this is where the drain plugs used to go...down from the heads...when you unscrew the sensor you will get almost 1 gallon of coolant from each side to drain out...

DO NOT DROP OR SHOCK THESE SENSORS.....

when you install sensor place a little sealant on the cleaned threads and tighten to 10ft lbs...like spark plugs...


with the sensors out and thermostat is out run water into the thermostat hole and let the water flow out the drain holes in the block..


don't spill water / coolant on the electrical parts though..

[crobar1]

Got it done. A simple flush of the core and overflow tank and got all the gunk out.
Thanks for the help and support.

[j cAT]

Originally Posted by crobar1

Got it done. A simple flush of the core and overflow tank and got all the gunk out.
Thanks for the help and support.

If you can spare a minute ..can you explain how the coolant got gunked...I know mixing non dexcool with other coolants will do this...

[crobar1]

Originally Posted by j cAT

If you can spare a minute ..can you explain how the coolant got gunked...I know mixing non dexcool with other coolants will do this...

I have owned this car from the dealer in 1996 and embarassed to say I never flushed the cooling system. I live on a ranch where dirt and wind is everywhere and constant. The only time I opened the cooling system was about 5 years ago when I replaced the water pump.
When I dumped the plastic fill tank the bottom was coated with loose sandy dirt as well as a red iron looking substance stuck to the plastic. Nothing I tried desolved the red stuff so when my flushing ran clear I replaced it. So far all seems to be ok.
Thanks for the help and asking.