Coolant temp: Is this normal?

[REBELXSi]

So today it was like 40F which isn't very cold around here. I took a trip that was a few miles (<5) on which my car would have fully warmed up before then. Anyway, the temp took forever to warm up.

The question is... Is it normal for the engine temp to fall back down after idling with the heater on? I sat in my car with the heater on recirc for about 5 min after reaching my destination and the coolant gauge went from 1/2 to 1/4. Never saw that before. It gets way colder here and I've never seen that happen.

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[kshawn]

Yup. Normal. When it's - out I'll see it drop even on the highway. I've been considering getting somthing to semi block the radiator during winter.

 

[REBELXSi]

Yup. Normal. When it's - out I'll see it drop even on the highway. I've been considering getting somthing to semi block the radiator during winter.

Wow, I've never noticed it happening before. I'm sure it's never happened in any of my other cars.

Very interesting.

 

[DRuby]

What's the "modern" equivalent of the mechanical engine block thermostat? Sounds like that isn't modulating the coolant flow, like when the old thermostats were stuck open.

 

[SDAlexander8]

Yup. Normal. When it's - out I'll see it drop even on the highway. I've been considering getting somthing to semi block the radiator during winter.

I’ve seen this on a semi truck recently. Basically like a bra for the bumper that obstructs part of the grill openings.

edit: no i saw it on a school bus actually

 

[DRuby]

Another cause to look for would be the coolant level or air in the coolant system. If for some reason air is trapped in the system, there will be insufficient coolant circulating. Probably won't steam in overheating.

I had a Mercury van. After we hit a deer and replaced the radiator, it never got up to temp. The cabin heater core probably kept air trapped for some reason. Probably should have bled the system by taking off a heater hose but with two young kids, other things had priority. At idle, there was no cabin heat.

Bottom line in my opinion is that this is an abnormal condition that a good mechanic or dealer(?) should look at. Having an engine running cold invites other problems like rich mixture and fuel/oil dilution that will increase engine wear.

Work arounds like grille baffles are not the way go. The engline needs to be at a constant temp.

 

[repeet]

For three years I've been reading threads about how our little 1.5 liter engines don't generate enough heat at idle to overcome the winter cold. That's with the heater on, acting as a radiator that is.

 

[Anger]

Same thing happens with mine and its quite normal. I just turn the fan off and have the temp at "Low" until the car really warms up. That is at least 10 minutes after some driving. In the mean time, only seat heating. Kind of rough when outside temps are really low but I prefer the engine to be happier than me...!

 

[JT Si]

My old 1996 Honda Civic with the D16 would absolutely have the temp gauge go back down even after being fully warmed I'd it was below 40F. I didn't even need the heater on to cause that.

I wouldn't be surprised if that was also the case for our engines. They have a bit more thermal mass and more coolant to hold heat but if it ain't outputting heat it ain't going to stay warm.

 

[REBELXSi]

My old 1996 Honda Civic with the D16 would absolutely have the temp gauge go back down even after being fully warmed I'd it was below 40F. I didn't even need the heater on to cause that.

I wouldn't be surprised if that was also the case for our engines. They have a bit more thermal mass and more coolant to hold heat but if it ain't outputting heat it ain't going to stay warm.

Just thought it was odd. My last car (Honda Fit) had a N/A 1.5L engine and never did that. Oh well.

 

[amirza786]

Damn, 40 degrees? When it gets 50 degrees here it's like deep freeze and we start pulling out the heavy jackets, mittens and boots. California....sigh

 

[REBELXSi]

Damn, 40 degrees? When it gets 50 degrees here it's like deep freeze and we start pulling out the heavy jackets, mittens and boots. California....sigh

40F in December is a nice day here.

 

[amirza786]

40F in December is a nice day here.

Californians when it's 40

 

[TypeSiR]

Californians when it's 40

Lately, it’s getting in the low 50s at night. In this kind of weather, we don’t go outdoor without donning the full-Eskimo attire to avoid the shrinking sausage syndrome. When’s Groundhog Day again?

 

[amirza786]

Lately, it’s getting in the low 50s at night. In this kind of weather, we don’t go outdoor without donning the full-Eskimo attire to avoid the shrinking sausage syndrome. When’s Groundhog Day again?

Very, very cold for SoCal. I lived in Santa Monica around 1994 (3 blocks the Santa Monica Pier), and I sometimes I used to go to the beach in the middle of December, many times at night! In shorts! Take that East Coasters, Mid-Westerners and other cold climate dwellers!

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