running hot? or worn gauge; it's original

[66notch]

I'm having issues with cooling, my coupe is a survivor 289 4 spd , just got it recently and after hanging a few shifts it blew off a heater hose apparently due to a rusted out clamp. so I promptly changed out all the hoses and clamps and dropped in a new 195 thermostat.

but!
it runs up to the hot on the OEM temp gauge and hangs there for quite a bit. it drops (assumably when the thermostat opens) but still hangs a bit high IMO. its fine on highway but stop and go in the city it climbs up on the gauge. hasn't overheated but the gauge travels up and down probably 20% on the scale between city and hiway runs. warms up at idle a bit also.

both exhast pipes blow a little steam as it warms up but noticed the right bank blows a little longer after the left clears, it does clear. compression is 150 in #1 and 160-165 in the others. not loosing coolant.

go figure

what's happening here? I'm thinking it's old and a little clogged. but can't seem to shake a suspect head gasket on the #1 right bank.

any ideas?

.

 

[AzPete]

First, find out if it is running at an abnormal temp.

Burning water/coolant will make the plug white compared to the others I believe.

 

[66notch]

plugs were all tan but a recheck is in order. Good plan to confirm the temp, think I'll pick up a heat gun at Canada tire, cheap like borsch, check the true temp.

do these OEM temp senders or gauges loose calibration?

Thanks

 

[AzPete]

do these OEM temp senders or gauges loose calibration?

Thanks

Not so much that they lose....they were never that accurate to begin with. The Constant Voltage Regulators can change over time.