1994. Idles fine. While driving, why does temp gage drop with little heat?

SOURCE: engine running hot

Check the condition of the coolant.
If you have any indication of oil, the headgasket could be bad.

SOURCE: No Heat in 99 Taurus

Just finished fixing my daughters 1999 taurus heat. It would blow warm only when running down the road. At idle it blew cold. I started with replacing thermostat, and water pump because they are the easier fix. Still did not help. Then I replaced the heater core. A daunting job but not that hard to move the dash slighly out of the way to replace. There is a good write up at tarusclub.com. After that, heat was better but at idle, it would still blow cool sometimes. Researched and found answer. Park car on the steepest hill you can find with front of car up. Start car and take off reservoir cap. Let car warm up and keep rpms about 1500. After a while the fluid will come running out of the car and all over the place but it will bring air bubbles with it. Reduce rpm, add more fluid and repeat about 3 times. It will make a mess but after that, the heater works perfectly. We get heat long before the temp gage indicates any and it never blows cold unless you lower the temp.

ricky horwood

• 128 Answers
• Posted on Dec 27, 2008

SOURCE: High idle in cold weather

this is normal for a car of this age
carburetor type motors have a automatic choke
this is activating when you start your car as it is so cold
i would not worries about it
it is designed to make it easier to start your car when it is cold my car dose the same thing
hope this helps
ricko

SOURCE: Temp Gage

sounds pretty normal. its not overheating but if you still want to do anything try replacing the thermostat and see it it changes

SOURCE: Heat blows cold when car is idling

You have an air pocket in the cooling system. To bled it out you will have to park vehicle on an incline or jack up the front end untill the radiator cap is higher than the heater core. The remove radiator cap and run engine until warm then hold rpm to about 1200 rpm's and top off coolant level until you have no more bubbles.