Is it normal for temps to rise during a long idle?

[afpj]

I should qualify my statement: my cluster gauge did budge above 210 to about 240 (3/4 to max) a few years ago when my clutch failed, hence the HD clutch after that. Of course, was not carrying my Bluetooth OBD Gizmo then so don't know what the "real " temperature was... Now the OBD reader is there all the time. This forum is awesome...

 

[rockola1971]

The cluster gauge is not exactly calibrated to high standard. ALso there is a buffer (delay) that keeps the temp gauge needle moving in increments over time instead of swinging left and right erratically. Most likely some sort of averaging over X amount of time. There is error introduced in the mix by the temperature sensor, loose or corroded wiring in the signal path can come into play, the instrument cluster itself (silver migration, stepper motor dying, never was calibrated correctly at the needle or someone has messed with it since it left the factory and a host of other causes. Even a fender bender could move the needle on the stepper motor shaft. We might only be talking about 1,2,5 or even 9.8 Degrees but its still an error. Even the temperature you read with a scanner isnt from a calibrated source. But we arent talking NASA equipment going to space here so 3,5 or even 8 degrees off isnt exactly going to make that much of a difference....until you start getting into fine tuning the engine with a tune and start custom mapping then it can be very important.

 

[Doubeleive]

When you guys are saying the coolant temp never budges sitting at idle, are you referring to the coolant temp on the cluster gauge or an independent source like torque pro or Scan gauge? My cluster gauge doesn't ever budge above 205 warmed up... just under the 210 mark, Even when torque pro was reading 215.

I mean the cluster gauge never moves, just stays where it always is which is normal, I live in central California it gets plenty hot here. The next 10 days is pretty much 100 everyday and will probably stay that way until about October with many days being much hotter. Batteries barely make it 3 years here the heat just kills them.
When I see the temp gauge go up at a red light, stuck in traffic or just sitting idling then I know something is wrong because it's not normal.
lets put it this way the ac has to be set on 60 or it's useless here the only thing that gets adjusted is the fan speed when it has cooled down outside or the vehicle has been closed up and ran for a good while so it will stay cool. If my temp gauge was moving up just sitting idling that would bug the crap out of me and I would figure out why, in my experience it has been the radiator every time which is why I flush it annually. It should be noted that I drive my vehicles very hard thus I follow a severe duty maintenance schedule

 

[rockola1971]

I mean the cluster gauge never moves, just stays where it always is which is normal, I live in central California it gets plenty hot here. The next 10 days is pretty much 100 everyday and will probably stay that way until about October with many days being much hotter. Batteries barely make it 3 years here the heat just kills them.
When I see the temp gauge go up at a red light, stuck in traffic or just sitting idling then I know something is wrong because it's not normal.
lets put it this way the ac has to be set on 60 or it's useless here the only thing that gets adjusted is the fan speed when it has cooled down outside or the vehicle has been closed up and ran for a good while so it will stay cool. If my temp gauge was moving up just sitting idling that would bug the crap out of me and I would figure out why, in my experience it has been the radiator every time which is why I flush it annually. It should be noted that I drive my vehicles very hard thus I follow a severe duty maintenance schedule

Our vehicles are old enough now and many radiators are original......and id be willing to bet alot of previous owners used tap water in the radiator after that thermostat, water pump or blown hose repair. And im sure you know tap water is a no no.
That tap water has minerals in it and they will collect in the radiator and start blocking the radiator passages which effectively makes the radiator have less cooling capacity.

 

[Doubeleive]

Our vehicles are old enough now and many radiators are original......and id be willing to bet alot of previous owners used tap water in the radiator after that thermostat, water pump or blown hose repair. And im sure you know tap water is a no no.
That tap water has minerals in it and they will collect in the radiator and start blocking the radiator passages which effectively makes the radiator have less cooling capacity.

I would imagine it also depends on the environment, here it just gets plain hot and heat kills everything. Some of the plastic used just can't handle it. When I bought my 2012 in 2017 it was 5 years old and had been a Arizona vehicle I knew it was going to need a radiator and sure enough a few months down the road it cracked on one of the end caps just so happened I was shopping for radiators not 2 days before it happened, lol

 

[rockola1971]

I would imagine it also depends on the environment, here it just gets plain hot and heat kills everything. Some of the plastic used just can't handle it. When I bought my 2012 in 2017 it was 5 years old and had been a Arizona vehicle I knew it was going to need a radiator and sure enough a few months down the road it cracked on one of the end caps just so happened I was shopping for radiators not 2 days before it happened, lol

I never was a fan of the "new design" crimp on oringed tank style radiators. They suck and fail. The old school brass radiators lasted a long time and were usually very repairable. The OEM's figured because metal prices were so "expensive" they could save a buck or two and use plastic tanks and charge us $100 extra. All profit, because they sure didnt fix an existing problem with the old school radiators. They just created one with the plastic tanks. With these plastic tanks it is imperative that your coolant cap maintain the pressure correctly. It doesnt take alot to blow a tank off or weaken the oring sealing system and cause a catastrophic leak. Never was a big fan of the removal of the radiator cap off of the radiator either.