170 Degree Thermostat
- Thread starter Steamer
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Why so low? ICE's usually run better at 190.
- Thread starter
- #3
I've been running my totally de-smogged F.5 with a 170 for a few years now and like it. Stays at 170 except under extreme unusual conditions and it may run at 172-173. No scientific calculations but it seems to run better and I like the lesser heat in the engine compartment.
I've never been able to find decent data on optimum operating temps for de-smogged engines so I'm just going by feel. I believe the one I have is beginning to fail. Gonna pull it to check but I'd like another new one on hand when I do.
I've never been able to find decent data on optimum operating temps for de-smogged engines so I'm just going by feel. I believe the one I have is beginning to fail. Gonna pull it to check but I'd like another new one on hand when I do.
morganism
SunkCostFallacy
I wouldn't go down temp on the thermostat myself. It seems to cause a loss in horses and gas mileage too. Also seems to build up carbon deposits faster, and clog the EGR valve more often.
So if not de-smogged , i would suggest not going lower. Even in the desert, truck likes higher temps better....
So if not de-smogged , i would suggest not going lower. Even in the desert, truck likes higher temps better....
- Thread starter
- #5
I am de-smogged so no EGR. I ran the 170 for at least 2 years. I changed spark plugs not long ago (just thought it was time) and the old ones looked fine. I'm not thinking I have a carbon problem.
It seems the normal operating temps on engines came along with the smog stuff.
I would like to hear someones first hand experience with a 170 T-stat on a de-smogged F, F.5 or a 2F
But anyhow, it looks like I'm not going to find a 170 anywhere. Sorry I didn't get several when I had the chance.
- Joined
- Apr 14, 2004
- Threads
- 1,472
- Messages
- 36,778
- Location
- 818-953-9230
- Website
- www.marksoffroad.net
I did leave you a VM reply yesterday, just before 11AM.
In my VM I said I currently only have the 160 and 180 thermostats in stock, as well as covering minimum order requirements.
If you want the 160 thermostat (which is what I run in my DD) we can talk on Monday.
In my VM I said I currently only have the 160 and 180 thermostats in stock, as well as covering minimum order requirements.
If you want the 160 thermostat (which is what I run in my DD) we can talk on Monday.
- Thread starter
- #7
Great Mark! I'll take a 160. I didn't get the VM. Not sure what happened. I'll call Monday.
Last time I tried to buy an FJ40 170 degree T-stat from my Toyota dealer, it was listed as NLA. Then we went to the FJ60 listings and lo and behold, the FJ60 still listed the identical 170 degree unit. I bought a couple as spares because I like the 170's more than the 180's. This was about 2 years ago but I bet they still have them in the FJ60 parts list.
EDIT: Guys, my apologies. I checked my stash of thermostats and it appears that the ones I got off the FJ60 listing were the 82 C version (179.2 degrees F). Sorry
EDIT: Guys, my apologies. I checked my stash of thermostats and it appears that the ones I got off the FJ60 listing were the 82 C version (179.2 degrees F). Sorry
Last edited:
- Thread starter
- #9
Good tip. I'll check it out.
DougAustin, would you happen to have the part #? I can't find it on any of the online Toyota dealers.
Thanks.
Thanks.
middlecalf
SILVER Star
I'm still wondering how a thermostat keeps the rig running cooler. Logic would say no thermostat then.
If the coolant runs through the system too quickly, it doesn't pick up as much of the heat, and thus it can't deliver the heat to the radiator to be cooled off. The same is true of solar water heating systems. There is an optimum speed at which the coolant can travel to pick up the most heat in the solar collectors. A little restriction can be a good thing. Also, if there is no thermostat to initially restrict the flow and allow the engine oil to warm up, especially if the radiator and water pump are working very efficiently, then the oil is less capable of properly protecting the engine rotating assembly.
It's 2:30 at night right now, but I will try to remember to check my parts stash tomorrow and post a photo of the boxes.
- Thread starter
- #14
Our thermostats not only open and close but they also control the bypass. When closed the bypass is fully open. As it opens, it closes the bypass.
When you run without a thermostat, the bypass is also wide open. Now, without a thermostat, how much goes through the engine and how much goes to bypass? IDK. I guess you'd have switch back and forth from with, to without to see measure the difference.
I just ordered a 160* from Mark.
When you run without a thermostat, the bypass is also wide open. Now, without a thermostat, how much goes through the engine and how much goes to bypass? IDK. I guess you'd have switch back and forth from with, to without to see measure the difference.
I just ordered a 160* from Mark.
middlecalf
SILVER Star
Yeah wasn’t trying to imply to not run w/o t-stat, poor facetiousness on my part. I haven’t had much success using a lower temp t-stat from spec for reducing overheating issues. I guess I’m not alone Low Temp Thermostats: What’s the Advantage?. 
- Thread starter
- #16
Yeah wasn’t trying to imply to not run w/o t-stat, poor facetiousness on my part. I haven’t had much success using a lower temp t-stat from spec for reducing overheating issues. I guess I’m not alone Low Temp Thermostats: What’s the Advantage?.
Right. A lower temp t-stat won’t improve a cooling system’s cooling capability. But if a cooling system is capable of running cooler, then a lower temp t-stat will allow it to.
Rooster47
SILVER Star
Yeah wasn’t trying to imply to not run w/o t-stat, poor facetiousness on my part. I haven’t had much success using a lower temp t-stat from spec for reducing overheating issues. I guess I’m not alone Low Temp Thermostats: What’s the Advantage?.
Thanks for sharing that article. I was reading through this thread with interest, as I've got an overheating problem to resolve. Sounds like the lower temp t-stat is more of a fine tuning one might do on a good working cooling system. Not a way to correct overheating troubles.
