Alright, I am pretty sure my themostat is going out. My ride will sometime run at normal 180 temp and sometimes crawl to 205. This happens when outside temps reach 100 and over. This fluxuation occurs whether I am idling, or driving on the road. I also get the error from my pcm that it is taking too long for my engine to reach normal operating temp during the winter season.

I already replaced my 180 stat once as my first 180 went out. I am sure this 2nd stat went out again. I bought this 2nd stat from Napa and it was nothing special.

I have a brand new radiator and water pump replaced a couple years back and only have 10k miles driven on them since the replacement. So I know my cooling system is still running optimum.

I like to get some recommended reliable brands of 180 stat from you guys so I won't have to revisit this issue again in a short time.

 

bump.

 

It could be possible the fan clutch is not engaging sometimes. Stats normally dont fail part of the time when they go bad they either stay open or dont open at all. I would first try to turn the fan by hand without the engine running then start it up and let it warm up and see what the fan does then.

 

Good recommendation Jason, however my fan clutch is working fine. I am 100% sure that it is my thermostat causing the issue.

 

Sorry Kensai, I was MIA.

I used a 180 Jet Stat that I got for $10.

For all others reading, on a 4.7l use a factory stocker replacement. For the 5.2/5.9L you may use any quality replacement. Make sure it is the type that "Fails to Open" which means if/when the stat fails, it fails in the open position.

IndyD

 

DO NOT USE the "Fail Safe" brand. They are the worst pieces of crap out there. Search just in this section and you will see that.

Now I do remember finding one that was a bit thicker and better built at one point, I think it was O Rielly's? I think it was the Murray Ultra Stat from them Part # 15358. Anyway you'll see the difference in the thickness. They are also 60% larger openings over OEM which helps in the towing areas. They are a fail safe style build.

Don't know much about the Jet's but I know Hypertech makes a good one and they kick Jet's butt on the tuners.

 

Can a general blanket statement be made here that 180 is better overall than a 195 as long as it is a quality thermostat such as you guys have listed above.

 

that only applies o the 5.2 and 5.9l engines, the 4.7 was designed to run a 190 and that is what i would recommend leaving in it

 

thanks for the recommendations. the last two 180 stats I bought was napa brand. Both stats failed where it took too long to warm up in winter and then on 100+ summer days, the temp gets much warmer than usual (200-210). I think the maintain 180-190 even in brutal DFW 100+ temperatures as my radiator, pump and fan clutch are still relatively new since I had my tranny swap.

 

wrong thread sry