Water temperature gauge tends to indicate high? Not sure.

[Guest]

I bought this 1998 Buick Custom. Has only 24,000 miles. This is my first Buick as well as a lot of firsts with this car. I am not familiar with Buick temp gauges....such as how hot should they read? What is normal? The gauge does not have the water temperature numbers as such, but has a needle showing how cold, warm or hot it is. The needle tends to be just under the halfway mark between cold and hot. Do any of you Buick owners have a similar reading? I take it that it is normal though. Also does anybody know the horsepower rating for that 3.1 litre engine and torque output? And what does the Century Custom weigh? I really

do appreciate any feedback. KB

[Guest]

Just letting you know not to worry about the hp and torque rating. I also have located those along with the weight of the car. Still wonder about the temperature gauge. Suppose at this time it's all normal. Thank you. If you have something to add or a comment about the temperature gauge, please do so. KB

[NTX5467]

Typically, the center mark on the gauge indicates approximately 210 degrees. The factory thermostats since the first exhaust emission control days have been 195 degree thermostats (except for some LT-1 Chevy V-8 applications which were lower) so seeing the temp needle just below the middle gauge mark is completely normal. Boiling point with a 15psi cap is approximately 260 degrees so there's still some reserve built into the system.

The 3.1L V-8 is a later version of the Chevy 2.8L V-6 that has been around for many years. It's standard in many late model Century models with the Buick 3800 V-6 being standard in the Regal models. The same engine is in the base Grand Prix SE with the base Impalas getting the 3.4L version as does the Grand Am and Alero.

FYI, I picked up a new Century Custom from the National Car Rental Emerald Isle this past Friday evening. It has the 3.1L V-6 and the temp needle has about one needle width between it and the middle mark on the temp gauge when it's up to operating temperature.

Enjoy!

NTX5467

[Guest]

NTX5467. Thanks for clearing that up. And you are exactly right about the position of the temp gauge reading being just left of the halfway mark. I am not sure exactly what you said about the thermostat. Is it a 210 degree or a 195 degree thermostat? If it is a 210, can I replace it with a 195? 210 sounds pretty hot even though a car may be designed to run that hot. I mean 212 is boiling. But if my thermostat is a 195, then never mind about my other question. Thanks again. BC98

[NTX5467]

Center mark should be about 210. Thermostat is rated at 195. Pressurized systems with 15psi caps will not boil until about 260.

Enjoy!

NTX5467

[Guest]

NTX5467, Thanks again for clearing that up. I starting thinking to myself that there can't be a 210 degree thermostat in the first place. Heat takes away horsepower as you well know. I don't know if you will return to this collumn, but can one change the thermostat to a 180 without affecting the emmisions? Have done this to other older cars in the past. Thanks. BC98

[NTX5467]

On modern computer controlled engines, I don't really see a need to get away from the factory 195 degree thermostat. Naturally, the many rent cars I've driven are reasonably new, but they never got past the middle mark on the gauge in our hot summers with the a/c going full blast. The electric cooling fans keep things under control.

The alleged power gain from using a 180 degree thermostat would be basically nil, even on a stock motor. If the compression ratio was a good deal higher than what it is, using a slightly cooler thermostat might keep the detonation limiter from kicking the timing back, but that would not be an issue with a stock engine these days. Also, the cooler thermostat might keep the computer from getting into closed loop as soon as it normally would and that would possibly affect emissions adversely. I know everyone that "talks chips" thinks they need the 160 degree thermostats in engines that didn't have them from the factory, but I perceive that is more hype than anything else. Plus, keeping the engine temps near 195 will keep the condensates and such cooked out of the oil better so oil life will be increased. Basically, I see no real compelling reason to get away from the factory thermostat specs on a stock motor. In prior decades, it was different.

Just some thoughts . . .

NTX5467

[Matt Harwood]

I wouldn't worry about the gauge at all--in most cars these days, they're little more than idiot lights that say hot/not hot. I doubt there's any real analog signal there to define temperatures as a needle position. I bet it doesn't even move once it's warmed up, regardless of load or conditions. It just shows that the engine is warmed up. If it isn't pegged into the red zone, there's likely nothing else to be gleaned from that gauge.

Like NTX5467 said, there's little reason on modern computer-controlled engines to try to artificially lower the coolant temperature. The temperature is high for many reasons, including those he cited, as well as for emissions reasons. And heat isn't a bad thing--heat <span style="font-style: italic">is</span> horsepower. What do you think moves the piston? But I know what you mean. The common myth is that a cooler engine will run better, but that's totally false. What you want is a hot lower end and a cool intake charge. On a low-performance engine like the Century's, there's really no point to going to extremes to achieve that, and it might hurt reliability and durability in the long run.

Hope this helps. Don't worry about temperature. Remember, your engine isn't overheating until you see steam.