Does not get warm-

[Libirm]

Hello all..

My cruiser has barely gets warm even after running for awhile.
Motor has about 10 k on it since being rebuilt by previous owner.

Typically I say the thermostat is stuck open and need replacement.


I thought I thought a thread up here in case there is something else I should check first.

I noticed that it house of the thermostat has a few sensors attached to it, not sure what they are for or do.

Thoughts?

 

[g-man]

2f engine? how did you confirm it is running cold? Just checking b/c it could be a bad temp sensor/wires/gauge. Does the return hose to the radiator get hot?

 

[Godwin]

The upper o-ring may have been left out when the thermostat was installed. PO may have used an old t-stat in the rebuild. A new t-stat, t-stat housing gasket, and upper o-ring are cheap enough that replacing all would eliminate the t-stat as the source of lack of warming. You want your engine to run at the optimum temperature so you need to correct this issue.

 

[lcwizard]

I had to run a 195 t-stat , even in AZ, or it would run cool enough in the winter that the heater was worthless.

 

[Godwin]

I had to run a 195 t-stat , even in AZ, or it would run cool enough in the winter that the heater was worthless.

I went this route a few weeks ago and heat output + mileage improved.

 

[Rustic76]

2x what @Godwin said. My bet is on the upper thermostat rubber gasket is missing or out of place. Seems like this happens to a lot of folks.

 

[lcwizard]

I went this route a few weeks ago and heat output + mileage improved.

So many people make the mistake that a cooler thermostat will make the car run better. I've run into cases will the Mexico manufacture
GM small blocks where a higher temp thermostat makes the engine run cooler than a lower. There's a relationship between heat transfer
from block to water, then water to air, through the radiator. Water that passes too fast through the block and radiator may not necessarily
be the most efficient. 195 is always my go to starting point

 

[php74]

If coolant serviced lately look up how to burp it.

 

[vipergrhd]

My thermostat was upside down when I opened it due to the same issue of running cold, as soon I replaced it and got the correct gaskets temp. went up to normal range.

 

[Seth_O]

Hello all..

My cruiser has barely gets warm even after running for awhile.
Motor has about 10 k on it since being rebuilt by previous owner.

Typically I say the thermostat is stuck open and need replacement.


I thought I thought a thread up here in case there is something else I should check first.

I noticed that it house of the thermostat has a few sensors attached to it, not sure what they are for or do.

Thoughts?

Has it never gotten warm, or is this new behavior? That will help narrow down the potential causes.

I just fixed this issue in mine, it was missing the gasket on top of the thermostat.

 

[Libirm]

It has never got warm since I had it...previous owner pretty much only used it summer...so he probably had no idea...I will try replacing the thermostat with a new 195 degree and see what happens....thanks for the help

 

[forestdan7]

Another vote for the rubber gasket on top of the thermostat. I had a lot of cold mornings in my truck before I read enough on MUD to figure this out. When I fixed it, I replaced the water pump, thermostat, gasket, and fan clutch all at the same time. Truck runs cool, heat blows hot.

 

[Code Red]

My temp gauge sits right in the middle of the range, but the heater never really gets past lukewarm. I also sometimes get a distinct gurgle right after startup. That being said, it was much worse before I replaced the T-stat.

 

[Seth S]

My observations as a new FJ owner doing a T stat change.

1. the new T stat came from the dealer with the housing gasket but no upper rubber gasket and being new to the machine I was unaware I needed one. When I changed in the new one I tossed the old upper because I didn't realize it was necessary. after reading about it on here I went back in the next day and put the old gasket back in until I could get a new one.

2. The thermostat seems to upside down just as easily and I can see how it could easily be put in wrong

3. I forget which temp t stat the dealer got me but once the truck warms up the cab gets nice and toasty now.

 

[pesbybeach]

Agree with Godwin. I had this exact issue when I bought mine. The rubber gasket was missing. Replaced tstat and gasket, now it runs in the middle of the band.

 

[Godwin]

My t-stat thread from a few weeks back

Thermostat change, fuel mileage bump

 

[Libirm]

Thanks for Help Jim- Looks like that there is sound reason to go with a warmer T-Stat.

 

[g-man]

Image of a land cruiser thermostat, seal and gasket and how it sits in the housing. Place the thermostat in the groove in the bottom housing first.

Another way to diagnose a stuck thermostat is checking the tension on the radiator return hose by squeezing it with your hand. The hose between the thermostat housing and the radiator. When you start the motor cold it should build pressure but still be cold and tight after a few minutes. When the motor reaches operating temp the thermostat opens and the hose gets hot quickly. If it's stuck open you probably never get a tight hose and will gradually get warm.

 

[morganism]

You should also drop the fan blower, and try and vacuum off the heat exchanger for the a/c. It gets clogged up with leaves and grit, and will really reduce airflow into ductwork. Does the rear heater work well ?