1995 Buick century overheating

[Ovar]

Hi all, I have a 95 Century with the 3.1L motor. I just bought the car with 81,000 miles on it and it seems to want to overheat. I turn the heat on full blast and that keeps it from getting in the RED. After driving it and letting the engine get hot I checked the top radiator hose and that was hot so it does not seem to be a thermostat problem.

Any other ideas on what it could be?

[GTP Dad]

Did you check to see if the radiator was hot too? It is possible that the radiator is blocked and properly cooling the water. If that is OK then I would go ahead and replace the thermostat along with the coolant especially if it is pale in color or looks like it has never been changed. I recommend a 50/50 mixture of Prestone Extended life and water. Also make sure you get all the air out of the system. Finally, since you have the coolant drained anyway you may also want to change the water pump as it may have gone bad and is not properly circulating the coolant.

[Ovar]

Thanks, I will test the radiator on my lunch break. I'll let you know what I find.

[HotZ28]

In addition to the things mentioned, have the coolant system pressure tested; you could have a cracked head allowing combustion gasses into the coolant.

[Ovar]

I checked a few more things out on the vehicle. The radiator felt hot and when I pinched and release the upper radiator hose I could feel a rush of fluid going through the hose, so it seems that my water pump is working properly.

I also monitored my temp gauge more closely. This time I didn't turn on the heat and on a 15-20 minute drive home from work the gauge would hover 1 or 2 notched below the RED.

Is this normal for this make/model? In my experience with similar engines they usually run just below halfway on the temp gauge.

[GTP Dad]

This may sound stupid but do you still have the air dam under the car that directs air toward the radiator? If it is missing pick one up and replace it. These cars depend on that dam to put enough air through the radiator to keep the water and engine cool.

[Ovar]

I am not familiar with the "air dam". What does it look like? I looked under the front of the car and did not see anything that looked to be directing air towards the radiator.

[Ovar]

Wow, so another piece of the puzzle falls into place. A closer look at the cooling fans reveals that the original wires were snipped and an attempt at running new once was put in place. The only problem is that the hot wire is not hooked up to anything.

So do you think this would cause my engine to run hot even while driving at highway speeds? It seems to me that the fans would not do to much going that fast?

[GTP Dad]

That is an excellent possibility, even at speed if the AC is on the fans will run to draw more air through the condensor. I would purchase a used set from a wrecking yard or you can contact Ed Morad at moradpartscompany.com. He may have a set that will fit your car.

The air dam I mentioned is just a black piece of plastic that hangs down under the chassis just behind the radiator. It is fairly small and looks just like a flat piece of plastic when you look under the car. It helps direct air into the radiator and they are easily torn off and can cause overheating issues.

[Ovar]

Regarding the air dam:

I know what your talking about now. My 1990 Century 3.3L had one of those. Its a flexible black flap that hangs down near the front of the car.

You were right my 1995 Century does not have one of those. I am thinking that a combination of not having an air dam coupled with my fans not working is causing my engine to run hot.

Do you think the junkyard would be the best place to try and find an air dam?

[GTP Dad]

I would certainly try there first. There are a lot of GM models that use the same platform as your car. You should be able to find one that will fit. The fans are certainly a possibility too.