Heater Problem

Greetings Everyone,

I have a 1989 Buick LeSabre 3.8 liter with electronic touch climate control. The Air handler is actuated by a vacuum line http://www.facebook.com/photo.php?pid=31123303&l=70c65e5abb&id=23605475from the engine. I am having a problem with Luke warm air coming from the ducts when i drive on the highway or at speeds above 40 mph. When Iam standing still or at low speed it blows very hot. I have checked the vacuum line coming form the engine to the air handler for leaks and have found none. Also I have installed a new heater core. I checked the long silver lever that moves the air duct door from heat to A/C and it is functions fine. Does anyone have any ideal on how to repair this? Thank you very much!!

http://www.facebook.com/photo.php?pid=31123303&l=70c65e5abb&id=23605475

Do you have an engine temp gage, if so what is your engine temperature while driving? I am thinking you may have a thermostat that looks like the one below (stuck open)

http://img695.imageshack.us/img695/511/112mw.jpg

i'm thinking the same thing.

I dont have a temp gauge on the car. It only has "idiot" lights. anf the car is not overheating.

I dont have a temp gauge on the car. It only has "idiot" lights. anf the car is not overheating. I am sorry, I think you missed my point, so let me try again. If the thermostat is stuck open, the engine will never reach operating temperature while driving with the current temps in Atlanta, GA (18-35 deg)! The pic I posted of the thermostat was recently removed from a car in the same area as where you live and had an excellent heater prior to the failure. As soon as we replaced it, the heat was back to normal. BTW, if you do not have a temp gage, you can use a scanner to check engine temp. (If Your ECT is working correctly) Good Luck, and in spite of Al Gores "Global Warming" prognosis, it is still very cold in Hot-Lanta!

Thank you so much HotZ28 il go get a new thermostat and let you know how it turn's out. I replaced the ECT and Computer back in August of 2009. And your right it ridiculous cold its 24 degrees right now.

I HAVE HEAT!! Your diagnoses was on the money. My old thermostat was stuck i put it in a pot a of boiling water no movement. Put the now one in and drove the 29 degree weather with HOT Heat! Thank you very much......