is water temp different vs coolant brand?

[Spykem4e]

I have a stupid question for you guys!

I have an 05 Cadillac CTS with 214700 kms and I changed the water pump at 200 000 kms because it was leaking very slowly on the engine front timming cover (was getting a sweet smell in the car) and while at it, I decided to change the coolant. The garage did flushed the entire system (radiator, engine and heater) and I really trust them. They put Havoline dexcool prestone instead of the GM dexcool (no problem for me there).

Before changing the coolant, when the engine was at normal temperature, the water temp needle was at 12 o'clock sharp.

Now, since the new water pump and coolant, its at 12 o'clock most of the time and sometimes, the needle is getting like 1 mm pass the 12 o'clock mark.

I know I know, 1 mm is nothing, but I'm a perfectionist and like to know why. Both fans are working okay. You can let the engine idle for 10 minutes and the engine is not overheating. You can idle in traffic and its fine!

I didn't change the thermostat because it was a 4-6 hours job just for the tstat. So is there any relation with coolant temperature versus brand?

 

[Chris142]

The Havoline Dexcool and the GM Dexcool are the exact same product. If there is too much antifreeze and not enough water that can make the engine run hotter.

 

[Bluestream]

More likely the concentration of coolant and not the brand. More water in the mixture is a better coolant, but lowers freeze protection. The flush may have removed some crud off the temp sensor as well.

 

[mechtech2]

Let's see...

New water pump of who knows what build type.

Flushed the system - and who knows what this did to the thermostat.

New coolant.

Warmer ambient temperatures.

The sensors and gauges are not getting newer.

 

[eljefino]

The water pump is pumping better and that's your issue.

I used to have a dodge spirit k-car, the gauge temp sensor was on the other side of the motor from the thermostat. So it saw cool water coming in from the radiator.

When I ran it hard, flying up a hill at 60 mph for example, the thermostat opened wider, the flow increased, cooler water came in the motor and touched the temp sensor, then soaked up more heat from the cylinder walls on its way to the thermostat, which was consistent.

What I'm saying is what you might think is, is contradictory. If your coolant conducts heat better, it warms up your temp sender better. I'd try seeing what a scan tool reports and even zap various pieces with an IR heat reading gun.