Engine Temp Reading 500h

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Aug 17, 2023 | 02:12 PM

Carbuff2

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From: NJ

Engine Temp Reading 500h

Here's ANOTHER nit-picking observation/question to go along with the 'setting MPG after each refuel' or the inaccurate fuel gauge (only takes 11 of 17 gal when indicating 'empty').

When we start our 500h after a night's 'rest' in the garage, there is always one 'segment' of engine temperature showing on the dash gauge. The ambient temp is ~ 81F or 27C in the garage.

Despite the fact that the engine generally starts after being off overnight, I've never had an engine that warmed up that quickly.

Anybody ever compared the dash gauge readings to actual with an OBDII scan tool?

Aug 17, 2023 | 02:30 PM

Urlik

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From: TX

Manufacturers want engines to warm up as fast as possible to meet emissions targets. To do that most new vehicles now have valving as part of the water pump that allows multiple cooling circuits. The turbo 4 has this as well. When you start a cold car only the coolant in the engine block is being circulated at first. Then it can bring in the heater core to the circuit and eventually the radiator. Modern coolant gauges are useless since they are just fancy idiot lights.

Aug 17, 2023 | 03:30 PM

Klamalama

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From: TX

Here in Texas, my garage interior is typically at 100F. When I start my 350h in the morning, it is already at the second bar. Yes, it does warm up quickly.

Aug 18, 2023 | 01:56 AM

ggebhardt

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From: Florida

Quote:

Originally Posted by Klamalama

Here in Texas, my garage interior is typically at 100F. When I start my 350h in the morning, it is already at the second bar. Yes, it does warm up quickly.

Same in Florida. Most the time I am at two bars when I start out in the morning. It takes less than a block to reach half way which is full operating temp. The 4 cylinder heats up fast and should be great in the winter.

Aug 18, 2023 | 07:10 AM

Carbuff2

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From: NJ

SO Has anyone correlated the displayed bars with an actual temperature?
Sounds as if we have a beginning: 81F is one bar on the dash, two bars is 100F.

Can't wait for Winter!

Quote:

Originally Posted by Urlik

Modern coolant gauges are useless since they are just fancy idiot lights.

Agreed...I know that many cars only have idiot lights for engine temp: Blue for a cold engine, Off for normal temp, and RED meaning you just fried your engine...

And even vehicles with actual 'gauges' have 'dampened' reading near normal so that owners don't worry when the temperature creeps up a few degrees in summer stop-n-go conditions.

I just wanted to get a feeling for an actual temp, since I doubt that an engine that has run less than 30 seconds is actually warm. Shouldn't you go easy on engines where the coolant (and oil) are not fully at an operating temperature?

I might still hook up my scan tool just to see if can get an actual reading. My OBD scanner is kind of old, though. Give me a couple weeks.

Aug 18, 2023 | 07:45 AM

Urlik

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From: TX

Quote:

Originally Posted by Carbuff2

I might still hook up my scan tool just to see if can get an actual reading. My OBD scanner is kind of old, though. Give me a couple weeks.

Shouldn't be hard to do since the ECU will know both the coolant and oil temperature at all times.

Aug 18, 2023 | 07:58 AM

Carbuff2

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From: NJ

Quote:

Originally Posted by Urlik

Shouldn't be hard to do since the ECU will know both the coolant and oil temperature at all times.

Not all cars monitor oil temps. Oil PRESSURE, yes, temperature no.

One of our sports cars could suffer cam-wiping/wear issues if the oil isn't warm...we have investigated monitoring oil temperature but sadly, no readings.