low operating temp, t-stat bad?
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Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
low operating temp, t-stat bad?
For the last week or so I have not beeen able to get the truck water temp above 165 degrees. Typically its more around 145-155 depending if I'm moving down the road or idling. Eot and ECT are only about 3 or 4 degrees different as always. Thinking bad t-stat. Coolant level is where it is supose to be. What you guys think?
Laughing Gas
Joined: Oct 2012
Posts: 794
Likes: 1
From: Ontario
T-stat is weak, opening earlier than 192 degrees that it's designed for.
Mine is the same way, opens at 172-180 usually, don't have the time to change it.
Changing it will be your fix, but will most likely weaken and not hold its designed temperature anyways
Mine is the same way, opens at 172-180 usually, don't have the time to change it.
Changing it will be your fix, but will most likely weaken and not hold its designed temperature anyways
FTE Leadership Emeritus
Joined: Sep 2003
Posts: 12,246
Likes: 761
From: Houston, Texas
Lower temps = low fuel economy because the truck is not able to burn fuel as efficiently.
My temps would never go past 188 degrees and my fuel economy would range from 14 to 15 mpg if it was in a good mood.
After installing a Mishimoto thermostat, my truck has no problem maintaining 200 degrees. My truck now averages 15-16.5 mpg easily and runs noticeably better.
The best thing is that the thermostat comes with a lifetime warranty.
My temps would never go past 188 degrees and my fuel economy would range from 14 to 15 mpg if it was in a good mood.
After installing a Mishimoto thermostat, my truck has no problem maintaining 200 degrees. My truck now averages 15-16.5 mpg easily and runs noticeably better.
The best thing is that the thermostat comes with a lifetime warranty.
FTE Leadership Emeritus
Joined: Sep 2003
Posts: 12,246
Likes: 761
From: Houston, Texas
Just make sure and replace the o-ring on the thermostat housing or you'll get to do it again.
Freshman User
Joined: Sep 2012
Posts: 28
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My experience with the thermostat, I put a new Motorcraft thermostat in about a year ago I think. It is already getting weak. My ECT tops out at about 182. Not terrible, but for being as old as it is I would've hoped it held up better.
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Former Vendor
Joined: Apr 2013
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Lower temps = low fuel economy because the truck is not able to burn fuel as efficiently.
My temps would never go past 188 degrees and my fuel economy would range from 14 to 15 mpg if it was in a good mood.
After installing a Mishimoto thermostat, my truck has no problem maintaining 200 degrees. My truck now averages 15-16.5 mpg easily and runs noticeably better.
The best thing is that the thermostat comes with a lifetime warranty.
My temps would never go past 188 degrees and my fuel economy would range from 14 to 15 mpg if it was in a good mood.
After installing a Mishimoto thermostat, my truck has no problem maintaining 200 degrees. My truck now averages 15-16.5 mpg easily and runs noticeably better.
The best thing is that the thermostat comes with a lifetime warranty.
Thanks, our thermostat will be here when you are ready!
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Thanks in advance.
Thread Starter
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Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
Changed the t-stat yesterday, temps are right back to the 190ish there suppose to be but I am fighting to get the air out of the system. Anyone have any tips? Seems to go to the 190 or so and stay right about there but my heat is coming and going like I have an air pocket. Any tips? The more I drive it the better it seems to get but it sucks when it's blowing cold air at times. Thanks for any info.
Laughing Gas
Joined: Oct 2012
Posts: 794
Likes: 1
From: Ontario
Changed the t-stat yesterday, temps are right back to the 190ish there suppose to be but I am fighting to get the air out of the system. Anyone have any tips? Seems to go to the 190 or so and stay right about there but my heat is coming and going like I have an air pocket. Any tips? The more I drive it the better it seems to get but it sucks when it's blowing cold air at times. Thanks for any info.
Thread Starter
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Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
This thing is really frustrating me, messed around with it for a while yesterday and had hot consistent heat for a while then this morning hop in to go to work truck goes up to 190 like its suppose to and cool air out of the vent. Then you would drive a ways and you would get heat for a few then back to cool. When I shut it off at work I had had hot air for some time. I wouldn't think I have a different issue as it was all good before I changed the t-stat but sure seems like the air would be out by now.
Thread Starter
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Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
Ok I'm at wits end with this thing. I will go out and work with it and get to where the heats blowing out take it for a ride works the whole time just like its suppose too. Hop in it this morning no heat all the way to work truck comes up to temp 190 to 200 is where it fluctuates up and down. No heat at all then just as I am getting to work it starts blowing hot, come to a stop it cools down a little then take off and it comes right back to,where it is suppose to be. Any idea what's going on, I wouldn't think a bad t-stat would do it, the heat worked perfect until 3 weeks ago when the temp wouldn't get above 160 degrees and more often than not it wouldn't get above 150.
Lead Driver
Joined: May 2014
Posts: 6,545
Likes: 13
From: Virginia Beach VA
If your truck is consistently in the 190s but blowing cold air out the vent, that's two different things.
Your issues may not be the temp of coolant, check the heaters controls (blend door) as it swings from hot to cold to blow the temp you select. If the door is broken (vertically mounted) and/or vacuum may not position it correctly.
Read the tread by Snuggyworm talking about ESOF hubs as its also controlled by vacuum. In that thread, someone posted a link to fix the blend door.
Maybe a good test for you is to turn on the air out the vent, then switch to 4x4 and see is if goes to defrost. That would at least say you have a vacuum leak. Only two things use vacuum, heater controls and hubs.
Your issues may not be the temp of coolant, check the heaters controls (blend door) as it swings from hot to cold to blow the temp you select. If the door is broken (vertically mounted) and/or vacuum may not position it correctly.
Read the tread by Snuggyworm talking about ESOF hubs as its also controlled by vacuum. In that thread, someone posted a link to fix the blend door.
Maybe a good test for you is to turn on the air out the vent, then switch to 4x4 and see is if goes to defrost. That would at least say you have a vacuum leak. Only two things use vacuum, heater controls and hubs.
Thread Starter
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Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
No auto 4wd I have the floor shifter. I am going to check later and make sure both the and out of the heater core houses are at operating temp. Odd that the blend door goes when I changed the tstat but I guess I have seen odder things happen.