Overheating or bad gauge?

[rustyBob]

The top will be hotter than the bottom .....hot coolent enters through the upper hose then flowes through the radiator to the bottom hose where it reenters the engine....your temp changes that show on the guage may just be the coolant "cycling" through the system....tstat opens hot coolent flows into rad. and when the "cooler" coolent from the rad. hits the tstat it closes and waits for the coolent to heat up again so it can "cycle' again....

[Blas]

Something that comes to mind, but probably not related, is the posibility of the impeller in the water pump being loose or with the veins of the impeller for a reverse rotation flow belt layout. But I assume your engine was fully dressed when purchased...Have you considered removing the thermostat to see if the problem goes away?

[Voyager]

Blas,

Thanks for the feedback. I’m still having the surging temp gauge issues.

Can’t seem to get that last phantom air bubble out (if it exists).

Can the capillary tube (wire) between the Smith gauge and sending unit cause the needle to surge if it is misrouted (too close to heat / plug wire / sharp bend)? Or does that just make it fail completely?

[Tommy]

Voyager,
You seem unwilling to give up on the idea that the gauge may be the problem. To safely resolve that issue I suggest one of two approaches. For about $20 you can buy an aftermarket temp gauge at any auto parts store and temporarily install it while leaving your stock gauge in place. If it does the same thing as the original gauge, then the gauge is not the problem. Another option, if the temp spikes occur while the engine is idling, is to take it to a repair shop or someone with an infrared temp sensor and have them see if their sensor spikes at the same time your gauge does. If you want an infrared sensor of your own, there is a Harbor Freight store that sells them not far from you.

It seems to me you need to resolve your doubts about the gauge so you can move on to solving the overheating problem if there is one.

[Voyager]

Tommy,

Great points. Appreciate your candor.

The 3-week old car is currently back at the dealer.

They said they tried 3 different Smith gauges - all spiked while test driven (doesn’t spike at idle).

They have also used their infrared temp sensor at idle. All readings normal.

I look to the dealer to resolve the issue at this time.

[Don Barnes]

You or your dealer needs to check the SCOF website. Thx. db #2723

[Voyager]

Don,

Done - joined SCOF 5 min ago.

However….

"Your Superformance Owners Association Membership payment has been sent and will be processed as soon as possible. Your password membership will be sent to you email in 2-4 weeks"

what.... 2-4 weeks????

Can I see information applicable temp gauge spiking info now??? I can pm you my email address.

Bob