Is thermostat housing hose get hot?

[svlx450]

I drained and filled with Toyota red coolant, replaced OEM thermostat and hoses. After engine idling for 15 minutes, Temp gauge at middle of C and H, Ultragauge indicated engine temp at 85°C /185°F. Fan running, top radiator hose getting very hot, but bottom and thermostat hoses were cold around ambient temp. Is this normal of how the cooling system works?

*** Hot liquid return from top hose, fan cool down the liquid and supply back to the engine through the thermostat opening... Please explain. Thanks in advance!

 

[dioscw]

If the hose is cool the thermostat hasn't opened yet.

 

[svlx450]

Yes, hoses is cool when t-stat hasn't opened.

 

[dioscw]

Yes, hoses is cool when t-stat hasn't opened.

Did you get all the air out of the system?

 

[svlx450]

Parked facing garage door, radiator cap off, engine idling all air out. Drove 5 miles, ultragauge shown around 85°c that indicated the thermostat opened right?

Can you check your rig to see if the bottom and t-stat housing hoses getting hot when engine at 85°C? Thanks

 

[dioscw]

Can't check for exact temp but when I replaced the thermostat the first time I run it for aprox 20 minutes with radiator cap off until the refrigerant level in the radiator when down. After that doesn't take more than 15 minutes to open the thermostat. I would suggest that you purge until you actually see that the thermostat opens.

The thermostat of my LC is of 82 degrees Celsius.

 

[svlx450]

I believed my t-stat opened at 82°C and Ultragauge shown engine temp running around 85°C during my short trip. Question is "The hoses ever get hot after the T-stat opened"? Thanks

 

[svlx450]

Picture after 15 minutes idling.

 

[91 4runner]

just be sure all the air has been bled from the system.

 

[dioscw]

I believed my t-stat opened at 82°C and Ultragauge shown engine temp running around 85°C during my short trip. Question is "The hoses ever get hot after the T-stat opened"? Thanks

Yes is does get hot like the upper hose. If the hose is cool the thermostat hasn't opened yet.

 

[dioscw]

Also when you purge the system the lower hose (thermostat hose) has to get hot if not there could still be air in the system. To purge the system you must run the engine without the radiator cap until the thermostat opens.

 

[Rwhat]

Have to driven it yet so it goes past 185*? I think you have most of the air out since its not climbing past 185* like it did when you called me yesterday.

You need to drive it longer. It's gonna take a while to get past 185* Did i modify the new fan clutch for you?

 

[svlx450]

I did drive local to home depot today, it stay around 188-190°F. Yes, you modified the new blue fan clutch last year and it ran very strong as soon as I start the engine, I haven't seen the fan clutch stop while the engine is running.

 

[Rwhat]

I did drive local to home depot today, it stay around 188-190°F. Yes, you modified the new blue fan clutch last year and it ran very strong as soon as I start the engine, I haven't seen the fan clutch stop while the engine is running.

Your fine now. Your fan clutch wont stop spinning foo as long as the engine is running.