ok so a hose from my thermostat blew today and while replacing that, i decided to replace my thermostat. while replacing that, i broke off the nut inside the housing so i had to take the housing off and take the broken nut off. replaced everything and started the car up and everything works just fine, but now i have absolutely no heat. it blows out cold air.

my car doesn't over heat at all had it running for like 15 mins, and then drove it around for like 15 mins. just i have no heat. there seems to be steam from behind the intake manifold. i'm guessing i didn't put the hose from behind there in right. you just push it in right? but car runs fine, and temp gauge is at middle and stays there. i'm stumped guys , i drive a 90 gs.

 

Might sound stupid but make sure you have enough coolant. When the car is low on coolant the heater blows cold.

 

Try bledding the system for air bubbles. How hot or cool of a thermo did you put in.

 

top off your coolant...take the car for a drive up and down hills...let it cool..check coolant level...repeat....not sure if the 90DA has a bleeder valve on the Tstat...otherwise thats all you could do. Your basically trying to "burp" your coolant system out of all that extra air that you just let in from draining it. The steam COULD be just left over coolant burning off from when you changed the Tstat...

 

Check the cable coming out of the firewall that controls the heater bypass valve. Have someone inside the car move the slider while you look to see if the cable is moving...

Same exact thing happened to me...the cable was binding and wasn't opening the valve. I could move the slider, but it would open the valve. It's possible you bumped the valve when replacing the thermostat and bent the bracket slighty...if you did, that will do it. Just bend the bracket so the valve is close to level and see if it works.

 

What I do w/ this problem is to start the car while its cold w/o the rad cap on, start the car w/ the heater on the hottest position. Wait for the thermostat to kick in and the coolant in the rad will suck up into the heater core allowing you to add more coolant. Fill it up to the fullest and it should stop idling funny and it will not blow cold air.


Modified by mugenpower92ls at 10:07 AM 3/11/2007

 

thanks for the reply guys, i'm going to try this and see what's going on. but ****. i have to go to a funereal today too. making thing so much better.

 

ok so i found out that it was my thermo-housing o-ring was bad. so i replaced that and now there's steam coming from that area. is there a special way you put it in, i just slide it in, and i'm still leaking from that area.

 

you can not slide that gasket in because it fits around the thermostat itself. I always take the grounds off the housing, take the lower rad hose off, and remove the housing to replace the thermostat because the o-ring fits around the thermostat and the little hole on the top of the thermostat points up. You are not sealing because you can not slide that gasket in. Take off the housing and put the o-ring around the thermostat and fit it in with the hole (it has a rivit like object sticking out of it that points up so the thermostat knows when to open, if the hole is pointing towards the bottom, this will cause the thermostat to open to early) in the thermostat's pointing up. Replace the housing making sure that the thermostat does not move around and tighten it up moderatly tight but not to tight that it busts the small 10mm. bolts that hold the housing on. After that replace the grounds and the hose and you should be good to go.

 

i know what you're talking about but it was the o ring, behind the thermostat housing itself. i don't know if that helps. because when i was just replacing the thermostat, i broke the head off one of the bolts. so i pulled the whole housing out. and the o-ring from that to the water pump pipe was messed up. all fixed though thanks for the input.