trainsimple

I have an issue with my water temp. gauge... I think. When I drive the car for maybe 5 minutes is goes up all the way to 250, which is the end of the gauge. If I goose the car a bit, or drive it on the highway, it shoots beyond what's readable to a position that would read 400+ if the numbers went that high. Then it will go back down to 250. The car doesn't seem to be over-heating. I probably drove it for 30 minutes or so to my mom's house, then 30 minutes back to my house.

Also, on the highway, I'm at about 3500 to 4000 RPM's even though the readline is 5500... does that sound right? I'm doing about 65. And it's a 66 327, 300hp (or so I believe) it's NOM.

Is there an easy way to trouble shoot the temp. gauge? And if I'm not up for it, should a general repair shop be able to? There is a Corvette shop close by, but I had an incident with them last time I brought it there and don't feel comfortable with them.

Thanks for any response to my dumb questions

macs65

4 speed or auto,what gears are you running???

62Jeff

I recently came across a 65 with a similar problem with the temp gauge.

The problem was a gauge that was not properly grounded to the dash housing.

michael m baily

I had a similar question the other day and have not had time to work on it, my question is, I did have the dash cluster part of the way out when fixing at amp guage, you talk about grounding the temp guage or cluster, how do you do that and how do you know visibly you have done it correctly, short of the guage working ,thanks Mike

62Jeff

In the case of the 65 I was looking at, a fiber insulator was placed between the gauge and the cluster, PLUS fiber washers were used between the mounting nuts and the cluster. As a result, the gauge was completely isolated from the cluster in terms of a Ground. The proper configuration was to not use the fiber washers with the nuts.

The cluster gets ground from a black wire with a female connector which attaches to a male tab mounted on the back of the cluster, above the Tach.

JohnZ

Have you checked your speedo accuracy? If it's correct, 3500-4000 at 65 mph says you have a 4.56:1 axle.

Best way to check the temp gauge is to shoot the upper radiator hose just above the thermostat housing with an I.R. gun and compare that reading against what the gauge shows at the same time so you know what the gauge is really telling you.

Ron Miller

A 4:11 rear gear should give you right about 3,250 rpm's at 65 mph. Check your speedo and tach a little closer to see just what you are reading at 65 . . . . .