dm_c4

When I drove my 1988 C4 two days ago I got no coolant temp at all on the display. It showed 'LO' all the time, even when the oil temp was high enough to show a number.

I never had this before. Is there a sensor broken or does someone have an idea what's the problem?

I dont feel so good without knowing the coolant temp at all

Thanks a lot!

8a8mfh

Depends on a lot of things.
Coolant could have leaked out....no coolant to read temp from. Not sure if thats possible, depends on where you've parked it, how long it's been sitting, etc.

The sensor might be disconnected or the wire broken. Infinate resistance = low gauge reading.

Or the sensor could be bad, but I doubt it.

dm_c4

Hi 8a8mfh,

Thanks. Well, no there are no issues with leaking or no coolant and the car was rolling every week.

I just wonder if the display says LO when the sensor is broken or if then something else or nothing shows up in this case?

Maybe there is someone who also experienced this.

8a8mfh

Temp sensor is bad or the wiring to it is open. Simply put.
Heres a link you might find useful.
https://www.corvetteforum.com/forums...t-says-lo.html

dm_c4

Oh cool thread. Thanks!! I wonder why I didn't find it in my search
I forgot to mention that some days ago I checked the spark plugs and as 'it (the sending unit) should be in the side of one of the heads' maybe I loosened a cable then.
So let's hope there is just a loose cable. I'll check it next weekend.

Cliff Harris

The gauge will read LO until the coolant temperature goes above 100°F.

If the sensor is disconnected the dash will think the coolant is at -40°F or °C (take your pick -- both answers are correct).

Vetterin

Do you get a temp reading on your trans? If not, replace your thermostat.

Cliff Harris

He said it's an '88. No way to read trans temperature in '88 unless you add an external gauge.

Vetterin

Opps........my bad! Meant to say OIL temperature.

dm_c4

Today weather was good enough to go on a little ride. So I tried it and it works again, I have temp in the display

So it luckily was just the cable I touched when looking for the spark plugs.

Thanks a lot for your replies!