Engine Temperatures Too Low
Safety Car
Joined: Jul 2018
Posts: 4,303
Likes: 2,055
From: Margate, FL
I've noticed there is about 20 degree differences between the digital and analog water temperature gauge. So I assume we are talking about the digital one here. I believe the analog gauge really just show 3 ranges: cold, normal and hot - and just moves slowly between them as needed. Most modern cars work this way since owners would freak out if they saw the dial constantly moving up and down due to traffic or RPMs.
Thread Starter
Team Owner
Joined: Sep 2000
Posts: 25,002
Likes: 2,703
From: Far NW 'burbs of Chicago
St. Jude Donor '13
This happened to my 2014 Z51. The thermostat was stuck partially open and the temperatures drop like you described. The yellow lines would come back on the tachometer as well just like when the car is warming up. I was out my bumper to bumper warranty, but it was covered under the power train warranty. The thermostat and its housing were replaced.
Hope this helps.
Hope this helps.
Was running 186-196 from Virginia to Ocean City this weekend, 60's outside. Not sure if it's my imagination but the 0W40 seems to bring the coolant temps down slightly.
I wasn't getting much heat in my DD a few years ago, thought the stat was stuck open as the gauge looked low to me. Took it in, and the tech insisted that I would get a code if coolant temps were out of range after a certain amount of time. I poked around just now and found this link.(not sure I'd do the power braking exercise though). A separate reading from an infrared gun might help you decide whether you have an issue.
I wasn't getting much heat in my DD a few years ago, thought the stat was stuck open as the gauge looked low to me. Took it in, and the tech insisted that I would get a code if coolant temps were out of range after a certain amount of time. I poked around just now and found this link.(not sure I'd do the power braking exercise though). A separate reading from an infrared gun might help you decide whether you have an issue.
Do you recall your coolant temp when the yellow arc would show up? Mine hasn't come up while driving after a few miles, and it goes away when the coolant and oil both get to something around 130'F.
Co-Vette-
I talked to the Corvette tech at our local dealer, a pretty sharp guy. He too said that if the coolant temp was significantly low or was taking too much time to warm up, it would give a light and set a code.
However, he also said that running slightly low, like a thermostat would almost-but-not-quite close completely, might not give any light or code.
He further stated that without a light or code, GM would be reluctant to pay for changing the thermostat under warranty. He suggested I drive it some more, write down some more sets of numbers, and if I still think it's running too cool then he'll call GM and try to get warranty approval.
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
2017 A8 Z51, oil cooler connected to the radiator.
During the summer, our coolant temp stayed below 200' and I didn't pay any attention to it. Oil temperature got more scrutiny but usually stayed 175'-200', if I was romping on the throttle it would get to maybe 225'. That seems normal.
Yesterday I was on a long highway trip:
Cruising speed 60-70 mph for over an hour.
Outside air temp 42'
Coolant temp 180'
Oil temp 166'-162'
When I got into a town, the oil went back up to 175', didn't note the coolant temp.
I'm wondering if the thermostat is stuck partly open, causing the coolant and oil (cooled by the coolant) to run low temps when there is lots of airflow through the radiator, but increasing somewhat in town with less air flow.
On our C6, coolant temp ran right at the thermostat temp (190') most of the time. No oil cooler on that car, so no comparison.
Can someone with a Z51/GS with the A8 tell me how your temps run in cold weather?
Thanks!
During the summer, our coolant temp stayed below 200' and I didn't pay any attention to it. Oil temperature got more scrutiny but usually stayed 175'-200', if I was romping on the throttle it would get to maybe 225'. That seems normal.
Yesterday I was on a long highway trip:
Cruising speed 60-70 mph for over an hour.
Outside air temp 42'
Coolant temp 180'
Oil temp 166'-162'
When I got into a town, the oil went back up to 175', didn't note the coolant temp.
I'm wondering if the thermostat is stuck partly open, causing the coolant and oil (cooled by the coolant) to run low temps when there is lots of airflow through the radiator, but increasing somewhat in town with less air flow.
On our C6, coolant temp ran right at the thermostat temp (190') most of the time. No oil cooler on that car, so no comparison.
Can someone with a Z51/GS with the A8 tell me how your temps run in cold weather?
Thanks!
Race Director
Joined: May 2001
Posts: 15,323
Likes: 2,077
From: Guelph, Ontario
Race Director
Joined: Aug 2015
Posts: 12,244
Likes: 4,739
From: SE WI
Yeah you want to boil off any moisture. Too hot or too cold are both bad. Mine only gets a tick over 200 if I’m accelerating hard for a while. A tick under 200 if I’m just driving mellow. Grand Sport M7.
Last edited by Zjoe6; Oct 16, 2018 at 08:51 AM.
Intermediate
Joined: Jan 2022
Posts: 25
Likes: 18
From: Fort Lauderdale
Bumping this thread as I just picked up my 2019 GS and I've noticed that my oil temperature never really gets above 180. I've also noticed the yellow ring in the tach appearing randomly and going away even after the car should be at operating temp.
I know the 2019 switched to 0w40 and that may reduce the temperature a bit in normal driving but the yellow ring showing up again after driving for more than 20 mins is a bit weird.
I'm wondering if it's a thermostat issue.
I know the 2019 switched to 0w40 and that may reduce the temperature a bit in normal driving but the yellow ring showing up again after driving for more than 20 mins is a bit weird.
I'm wondering if it's a thermostat issue.
Thread Starter
Team Owner
Joined: Sep 2000
Posts: 25,002
Likes: 2,703
From: Far NW 'burbs of Chicago
St. Jude Donor '13
^^^
Probably right about the thermostat- here's what I recently posted recently in another thread:
I had a similar situation on our 2017 Z51, the link above (ed- this thread) shows the thread I started. The problem was very occasional, and the reduced rpm arc on the tach did not re-appear..
Originally, the dealer didn't find any codes or easily-spotted problems.
Last summer I had the coolant flushed and asked them to install a new thermostat. If the original was working ok, then I'd pay for the new thermostat. If the original was bad, then they should charge it as a warranty repair.
It showed up on the bill as a warranty replacement, but they may not have actually tested it- this dealer is good about fixing things like that if my complaint makes sense.
Since then, I haven't had any problems but don't drive in cold weather a lot.
Probably right about the thermostat- here's what I recently posted recently in another thread:
I had a similar situation on our 2017 Z51, the link above (ed- this thread) shows the thread I started. The problem was very occasional, and the reduced rpm arc on the tach did not re-appear..
Originally, the dealer didn't find any codes or easily-spotted problems.
Last summer I had the coolant flushed and asked them to install a new thermostat. If the original was working ok, then I'd pay for the new thermostat. If the original was bad, then they should charge it as a warranty repair.
It showed up on the bill as a warranty replacement, but they may not have actually tested it- this dealer is good about fixing things like that if my complaint makes sense.
Since then, I haven't had any problems but don't drive in cold weather a lot.
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