UPDATE, THANKS and next issue!

Maintenance/Repairs
1

First I would like to thank all who helped me on my last post about losing coolant but not leaking it on my 1998 Buick 3.8 with 120,000 miles. The car did indeed have a bad intake manifold and was dumping coolant into the intake. I have no idea why it was not blowing white smoke, but it was full of dyed coolant. I did not even an ultra violet light to see it it was just green all over !! All and all it was about a 4hr job, including 30 min of trying to get the PVC valve back in.

Now for the next issue, the car is running very cool. I replaced the thermostat today thinking that may be the issue, but it is actually running even cooler now. I believe the issue is that my fans are running all of the time (well whenever the HVAC is on even its on heat). Where is the temp sensor for the fans?? What else can the issue be?? THANK you once again in advance !!

2

The fans will run if the HVAC system is on. It’s the way they’re designed.

However, the temp sensor should be a plug in the radiator with two wires coming from it. It’s a simple device, and just shorts when it hits a certain temp.

3

Please post the results of the first problem in the original post for anyone else looking into a similar problem.

And, as far as the new problem, you may need to purge the cooling system and especially the heater core of any trapped air. A lot of cars can get this accomplished by raising the front end very high, like a steep driveway or on ramps. Then run the car with the radiator cap off to bleed out the air. The object is to get the radiator fill to the highest point in the system.