‘90 running way too cold
Thread Starter
Intermediate
Joined: Dec 2025
Posts: 44
Likes: 1
‘90 running way too cold
this is as warm as it got after warming up for 15 min and driving for 40.
i recently purchased this 1990 c4 and noticed that it’s been running cool since i got it. i live in mid-atlantic part of the us and it’s about 30-50F right now during this drive it was about 43F. the reason i’ve been looking into this is because of the gas smell in my oil i believe it’s because my car is not getting hot enough to evaporate excess fuel and condensation.
but what do you guys think?
(this is my first post i tried posting this last night but it somehow got deleted i hope i’m doing it right )
Melting Slicks
Joined: Nov 2016
Posts: 2,253
Likes: 3,076
From: So Cal
2023 C4 of the Year Finalist - Unmodified
Looks about right for the low end of the operating range. Cooling fans come on at about 5/8 scale. The analog gauges are not linear. They should be used as an indication of whether the needle is where it usually is under the prevailing conditions. Not used to discern an actual value.
If your car has the C68 Electronic HVAC controls, you can use them to read the coolant temperature actual value from the data stream that the ECM uses.
Engine running. Hold fan speed Up and Down arrows until "- 0 0 " appears.
Push fan speed arrow Up until " - 0 1 6 " appears.
Push Fan Icon. The coolant temperature in C is displayed.
To exit the diagnostic, push any Mode button, or cycle the key.
100 deg C is 212 deg F. 10 deg C is 18 deg F. 1 deg C is 1.8 deg F. It's not tough to do the conversion math in your head.
Your car may have a 180 deg F thermostat installed by a PO. 180F is 82 C.
If your car has the C68 Electronic HVAC controls, you can use them to read the coolant temperature actual value from the data stream that the ECM uses.
Engine running. Hold fan speed Up and Down arrows until "- 0 0 " appears.
Push fan speed arrow Up until " - 0 1 6 " appears.
Push Fan Icon. The coolant temperature in C is displayed.
To exit the diagnostic, push any Mode button, or cycle the key.
100 deg C is 212 deg F. 10 deg C is 18 deg F. 1 deg C is 1.8 deg F. It's not tough to do the conversion math in your head.
Your car may have a 180 deg F thermostat installed by a PO. 180F is 82 C.
Last edited by IHBD; Dec 11, 2025 at 10:40 AM.
Thread Starter
Intermediate
Joined: Dec 2025
Posts: 44
Likes: 1
thank you very informative i will try that when i get home from work today. do you think the gas smell in the fuel is a separate issue? or maybe i just have to change oil more frequently in winter since car doesn’t get hot enough to evaporate it. i’ve tested leak down tested my fuel system and pinched off return and sending line and all came back just about the same reading. i don’t think fuel is leaking out of my system
