Q Running Cool in Colder Temperatures

[Flagship-Q]

Alright...I'm kinda stumped on this one. My Q45 always runs right in the middle of the temp gauge (in the normal operating range) all the time. Lately, when it gets down to 10 degrees or so, it barely gets in to the bottom of the normal operating range resulting in a VERY long warmup (I have the auto temp on 80 and it runs continuously at high to medium fan speeds). A 30 mile drive sometimes doesn't result in a normal temp. I did notice that the radiator (?) cap on the front of the engine has the seal somewhat cracked. So I don't know if it's not building pressure or what. Coolant levels are correct. Any ideas???

[elwesso]

Thermostat.

[DrewQ45]

Wes is right, your thermostat may be stuck in the open position allowing continuous flow of coolant, however, you are dealing with some very low temps there. With your heater running at 80* and fan on high, you are usurping much of the heat away from the engine. Even here in ATL in say 35-40* temps, my thermostat drops to 1/4 mark on the highway with heat on blast. Soon as I get off the highway it climbs a bit and if I turn off the heat, it climbs more to normal. You may be seeing normal operation there. If you have no leaks, I say drain some coolant from the radiator during the extra cold temps..not a lot, just enough to normalize the temp. Keep what you drain in a bottle in the trunk for when the temps warm up. Running cold is a lot better than overheating.

...Drew...

[Jesda]

Low coolant? You ever hear a swishing sound at startup?

[Q45tech]

Even at 0 F and 80 mph the coolant temperature should not drop below 164F otherwise the ecu cannot maintain closed loop.

The thermostat has a short life [the rubber surround] unless [even if] you are meticulous about coolant changes...............the acid build up [aluminum engines] ..............check ph+ frequently or just change every 2 years.

We see it constantly as the Consult won't do it's thing until 174F...........bad thermostats............I have to trick ecu into seeing 174F or wait a half hour for engine to warm up most don't ever get to correct temp.

[DrewQ45]

What does 164* translate to as far as the temp gauge, a little below halfway?

Normally my temp gauge is always just a smidgen past halfway point. The only time I see the temp drop is as he described, with the addition that I'm doing highway speeds. Please, folks try this next time you're on the highway... bump heat up to max, hit recirculate then watch temp gauge. Let us know what happens. Today is a good day too cause it's cold as hell! Well, here in ATL anway.

[elwesso]

the temp gauge is so innaccurate, id think anything between 165F and 200F would be right in the middle-ish...

My old Q sat right below 3 o clock, this one sits right at 3 o clock...

[Flagship-Q]

That's exactly where mine would be at (3 o'clock) until lately. Just double checked coolant level and it's right in the middle between Min and Max in the overflow. So the coolant cap on the engine doesn't come into play here either? Just drove home today (25 deg.) - 15 miles and it never reached 1/4 high on the gauge. Thanks

[qship96]

tried full heat at 80-85mph today in 30 degree temp.-gauge read normal{ tad below horizontal} original thermostat at 170008 miles.

[demhaizar]

elwesso is correct!

I had a similar problem, i live in Michigan.

Car would not warm up at all when it was cold outside, but if it was in the 30s it would be ok most of the time until i was moving then it would drop.

Changed the thermostat (about 30min) and now does not matter what the temp is outside when she warms up, she stays at ~3 o'clock

L8R