Temp rises at highway speeds

[Lobo1]

I only looked for a few minutes on a trailblazer forum.
The info it said was that the temp sensor sends a signal to the computer and the computer sends a signal to the dash. It also said that it was often wrong and to check the temp by another means. I dunno?

I only worked on cars where the overflow went to the ground and when they puked sometimes the cap wouldn't hold the specified pressure.

Well my son said it is fixed. He put a new temp sensor in and problem solved. Temp gauge stays steady at 210 with air on and no matter the speed.

Thanks for all the input. Y'all carry on.

 

[Ken Ford]

I'd pull and boil the thermostat on the stove to see at what temp it opens up at.

Cheap part and same amount of work, why not just replace, if there enough question to remove?

 

[Ken Ford]

Well my son said it is fixed. He put a new temp sensor in and problem solved. Temp gauge stays steady at 210 with air on and no matter the speed.

Thanks for all the input. Y'all carry on.

That's good, I was thinking that the fluctuation didn't seem right, with no loss of fluid.
Probably damaged the sensor when it got hot.

 

[MRM]

Cheap part and same amount of work, why not just replace, if there enough question to remove?

Exactly. It's a cheap part. Verify it's working properly. You could replace it with an equally cheap part that could be maybe working like the one it replaced.
It falls under troubleshooting.
And it is an old technique.
I suppose years ago money was money.
It's analogous to testing a relay before replacing it or the fuel pump.

 

[Ken Ford]

Exactly. It's a cheap part. Verify it's working properly. You could replace it with an equally cheap part that could be maybe working like the one it replaced.
It falls under troubleshooting.
And it is an old technique.
I suppose years ago money was money.
It's analogous to testing a relay before replacing it or the fuel pump.

Exactly. It's a cheap part. Verify it's working properly. You could replace it with an equally cheap part that could be maybe working like the one it replaced.
It falls under troubleshooting.
And it is an old technique.
I suppose years ago money was money.
It's analogous to testing a relay before replacing it or the fuel pump.

How do you accurately deterimine what temp it opens at? That is a go-no go test only. If there is enough question to take it out and see if it functions just replace it and be done with it.

 

[MRM]

I've seen bad ones straight from the box. Sometimes they can be intermittent, slow, etc.

It's a tool for your kit that weighs nothing. It's cool, ask the oldest man you know if they have ever boiled a thermostat.

I might go boil one right now.

 

[MRM]

I'm saying you got an issue.
You throw a new thermostat in there.
Still have a problem.
If it is a bad one you just put on, chances are you are going to spend more time and money before you figure it out. Especially if you never boiled one.

It's cooking, picks in a min.

 

[MRM]

It is a new to me engine I'm working with.
Cracked at 198
190 stamped on it.
It opened this much at 207

 

[MRM]

Back closed by 189.

I'd take it over a new one at the store all day. That's just me and I'm odd. About five or six more times and I'd be sure it wasn't my problem. Things were simpler in the 60's!

 

[Ken Ford]

Back closed by 189.
View attachment 880185
I'd take it over a new one at the store all day. That's just me and I'm odd. About five or six more times and I'd be sure it wasn't my problem. Things were simpler in the 60's!

OK