LigHtEmUp01

i have no heat, the heater hoses going into the firewall are cold. is there and sort of relay or vacuum that i ccan check or anything else?

lt1slowz28

vacuum is the one on the engine harness, the only one that is actually a part of the loom on the passenger side... try popping the line off and see if you can run some water through it with a hose to make sure it isn't clogged.

94'BLKBRD

iTrader: (76)

Most people flush their heater core and get it to work that way.

itsslow98

iTrader: (18)

Make sure your coolant is full.

Paul Bell

iTrader: (9)

When I got my '94, the heater core was clogged. Pull the hoses off the engine end and using a water hose, send water in one end while the other end is pointed at the ground. When it clears, you'll be surprised how much gunk comes out. Do the same in both directions.

While you're digging around in there, check the vacuum check valve. They get brittle and crack.

http://shbox.com/1/vac_check_valve.jpg

Reassemble, top off and bleed. Enjoy the heat.

shbox

Vacuum has nothing to do with temperature control (only mode control). Temperature is controlled by a cable from the **** to the blend door.

If your heater hoses are cold, then there is probably a restriction. Flush it out.

Paul Bell

iTrader: (9)

I agree however, I always suggest checking the check valve on these older cars.

shbox

I wasn't saying not to. Just pointing out what controls what because the OP indicated he thought vacuum might be a suspect for heat.

I've had to replace my vacuum check valve. The new ones look a bit different.

Paul Bell

iTrader: (9)

Kewlz Rob. When are ya gonna make some shbox pages for LS cars?

shbox

If I ever have/get one, I guess that would be the time.

Paul Bell

iTrader: (9)

I suppose if anybody can keep a LT1 car running it's you!

FAD2BLK93

Would a fualty thermostat have anything to do with it in these cars? I have the lower 165 temp stat in mine and it takes forever to get warm. Almost want to go back to stock in the winter, but i am smelling anti freeze inside the car...so i am going to have to change it. Maybe i have a clogged one too.

shbox

A faulty themostat could restrict flow. If you smell coolant inside, the heater core probably has a leak. Hoses and/or core could have some clogs. You could have all three things going on.

02v8ta

iTrader: (8)

My car runs a 160 stat and I get plenty warm now that i replaced my heater core. If your thermostat is stuck open or periodically sticking open you wont really feel heat ever. I would replace your heater core since you are smelling it or even take off your glove box.panel, and heater core panel below it to inspect it. IF that looks alright, which i doubt from what you've said, then replace your thermostat with the same one.

I'm assuming your car is tuned for the 165stat? If not it'll just take longer to reach operating temps, you should still feel heat eventually.

LigHtEmUp01

thanks guys ill mess around with it when i get a chance

Jr.Samples

I know this is crazy but my heat works fine on warmer days above 60 degrees but when I need it no heat is there. The blend door is cable operated? The core is good and has been flushed. Above 60 degrees I can turn the cold/warm blend door back and forth and works good.

It pisses me off. How can this be so damn difficult!