1977 Temperature Gauge

[Chris1977]

Hi All,

I was wondering if anyone can help me perform some pre-diagnostic work on my 77. I just inherited this vette from my father. It is all original with 32,000 miles. However it was only started and driven a handful of times since 1986. That being said, much of the mechanicals need tuning.

When we started her up, she kicked right over and ran excellent despite the hibernation. However, the temp gauge refuses to budge. On '77's where would be a could place to start looking for the cause of this problem. All other gauges in the cluster are working and accurate.

Thanks in advance. Chris

[mike cobine]

Re: 1977 Temperature Gauge

Make sure there is coolant in it. If no coolant, the gauge won't move until the sender heat soaks through the mounting threads, then it is too late.

Sender is in the head on the driver's side. Check that the wire is still on it.

[Chris1977]

Re: 1977 Temperature Gauge

by too late as in I will "fry" the sensor or too late to catch my vette overheating???

Thanks,

Chris

[mike cobine]

Re: 1977 Temperature Gauge

When an engine with no coolant in it gets so hot it heat soaks the sending unit, the oil is cooked and probably the bearings.

It only takes a minute to pop the radiator cap and see if there is coolant.

If there is coolant, try this. When the engine is cold (just started), have the radiator cap off and see if the level drops WAAAY down (like 6 inches or more) after about 5 minutes or if it only drops an inch or two. WAAAY down means it wasn't full and probably the thermostat sealed too well so the filler thought he had filled the engine and radiator. (common)

If it does this, simply add coolant and water (50/50) while it is running until it is full as this means the thermostat is open and there is no air block.

Being very low can leave air around the sending unit so that it doesn't heat as the engine does and would give you a false reading of it being cold.