I saw this 203* thermostat on DieselSite. I was wondering if anyone is running this and what they have to say about it. I am doing a coolant system overhaul and plan on replacing my thermostat. If this one is better, Id rather spend the extra $13 over the Ford one.

 

DON'T DO IT! I had mine for two weeks before it stuck closed and nearly fried my engine. I was driving through Colorado and boiled all the water out of my radiator. I dropped the thermostat in a boiling pot of water and couldn't get it to open even a little. I do like the DieselSite billet housing, but I didn't notice a single improvement from the 203* t-stat.

 

I'm interseted in what others have to say. I have mixed feelings about this thermostat.
I'm still learning.

 

I did some searching but I want some fresh opinions

Heres a question.. If you change out the thermostat do you need to drain coolant? I was thinking "Heck.. these thermostats (180*, 195*, 203*) are only $20-40. What if I tied each of them."

It seems people's results seem based on their climate. I live in a very stable climate of 60*-80* year round. So theoretically, I could try each one and see which one my truck likes best.. right?

 

My truck likes it. I lost a little mpg when I switched back to the 195* for about a year. I have had (2) Dieselsite 203* stats and no problems with either one. My EOT stays in the accepted normal range even in 100+ degree ambient temps. I'm not going to switch back again. I gave my first one away to another member, who as far as I know, is still running it. It's probably over 5-6 yrs old now.

 

I'm a 203* believer.

 

I've been running one for nearly two years. The truck seems to run fine on it, I'll probably get another one next time. Avg mpg is 15-16 town/mixed and 17 pure 70+ mph hwy.

A water temp gauge would be nice to have for data collection if you are going to experiment with different t-stats.

 

About five years on my 203...Truck liked it from day one.

 

Skip it... Hotter coolant means hotter oil. If your truck is stock, or nearly stock its ok, but if you have anything more then a chip... Stick with the nice 195* stocker.

 

OEM here with no problems. Heard too many problems with the 203* for me to think its worth while.

 

My truck seems to like it. I've used it for about 5-6 years

 

I actually just installed a 180 yesterday. Jody mentioned trying it after live tuning when he saw my EOT run up to upper 230 range. Cruisin down the highway now, and the EOT is staying at 205 pulling a boat in some hills in north central LA.

 

Btw those #s when live tuning were with the 195 Deg thermostat

 

Personally I'm a believer that more heat = less life expectancy. These trucks do prefer to run at 200F or so. So with that I'll stick with the stock 195. Specially since I have a 6 speed and have no worry about auto trans temps.

 

Hey David.

I don't understand what you are saying here. If you were at the 230* range while live tuning and 205* range while towing the boat, how is the 203* stat effecting these temps? At 203* the stat is fully open.

I've been running the 203* stat for a few years now with no problems.