Thermostat potentially may be stuck closed…

[fumanchu182]

So after my last few passes at the track I noticed the car was not cooling down to the usual 192 degrees after a pass. I have a Jet Performance 10183 thermostat. While driving today, 66 degrees out, the car would not get cooler than 204 degrees. So a couple of things I’m thinking may be the culprit.

1. Mechanical failure.
2. Tune somehow has fans set for 204.
3. Air bubble.

I’m ruling out #3 because this would have surfaced a long time ago… And I can’t see if #2 is the culprit as the tune is opaque from OST… if the thermostat is stuck, does anyone have any recommendations and should I go with a cooler thermostat if I have to replace it?

 

[EricG]

If it was stuck closed, wouldn't your temperature just continue to go up as you ran the car? Either way I think you are stuck having to replace it just due to the uncertainty of it all...

 

[Jack_Toepfer]

Does the JET tstat have the bleeder hole to keep at least some coolant moving? That would explain why it’s not boiling over more quickly.

If you get it to 190* and the fans don’t turn on (you’ll hear them), I’d check your tune - but I highly doubt they’re waiting for 200+ to turn the fans on, probably low speed at 170 and high speed at 190 or so. Especially if you’re running a cooler tstat and OST knows about it, they would adjust your temps accordingly. Hopefully you can hear your fans turning on when your driving and the temp is over 200* or your fans aren’t working properly. Check fuse/relay.

Having said all of that, if you haven’t changed anything at all, and this is a new and unrelated problem - either your tstat is frozen shut, or your water pump took a dump. I think you may be able to tell which by checking the temp of the coolant hoses going to the rad and leaving the rad. If they’re both the same temp (according to your hand or a thermometer) then I would think that your WP isn’t keeping up and you may have lost some blades. If there is a significant delta between the 2, your tstat is frozen…

More importantly, that’s an awesome song on an amazing album.

 

[vortecd]

So after my last few passes at the track I noticed the car was not cooling down to the usual 192 degrees after a pass. I have a Jet Performance 10183 thermostat. While driving today, 66 degrees out, the car would not get cooler than 204 degrees. So a couple of things I’m thinking may be the culprit.

1. Mechanical failure.
2. Tune somehow has fans set for 204.
3. Air bubble.

I’m ruling out #3 because this would have surfaced a long time ago… And I can’t see if #2 is the culprit as the tune is opaque from OST… if the thermostat is stuck, does anyone have any recommendations and should I go with a cooler thermostat if I have to replace it?

View attachment 47381

I would go with a 180 if I had a tune. My 180 from my daytona threw a code on the Hellcat. I have a Milodon

Was your fans on or air on? I have noticed before if I have my A/C on which the fans are running it will stay at 203

 

[jonx96]

How long has the thermostat or tune been loaded?
The bleeder hole on the top needs to be on the top.
Go 180. I wouldn't go 160 as these engines are designed to run at some sort of operating temp.
Your fans should be screaming if it is truly stuck closed.

 

[jonx96]

Another possible issue is the thermostat you bought isn't flowing enough coolant. I know HHP even stated on the other forum in one of their posts their brand 180 tstat sometimes doesn't flow enough coolant on hellcats and they recommend the Mishimoto Racing 180.
Post #12 it was very honest for them to post something like that.
https://www.hellcat.org/threads/180-thermostats.15720/

 

[Stormtrooper1320]

More importantly, that’s an awesome song on an amazing album.

I don't know......I'd have to think about it....think about it...think think think about it......

 

[EricG]

Another possible issue is the thermostat you bought isn't flowing enough coolant. I know HHP even stated on the other forum in one of their posts their brand 180 tstat sometimes doesn't flow enough coolant on hellcats and they recommend the Mishimoto Racing 180.
Post #12 it was very honest for them to post something like that.
https://www.hellcat.org/threads/180-thermostats.15720/

Anyone have a current link for the Mishimoto? I have a Jet 10183 and it has been fine, but would like to have one of there...

 

[fumanchu182]

If it was stuck closed, wouldn't your temperature just continue to go up as you ran the car? Either way I think you are stuck having to replace it just due to the uncertainty of it all...

I did order a 180 off HHP, will be here in a few days. Car will be down till that gets here and the new fuel pumps.

Does the JET tstat have the bleeder hole to keep at least some coolant moving? That would explain why it’s not boiling over more quickly.

If you get it to 190* and the fans don’t turn on (you’ll hear them), I’d check your tune - but I highly doubt they’re waiting for 200+ to turn the fans on, probably low speed at 170 and high speed at 190 or so. Especially if you’re running a cooler tstat and OST knows about it, they would adjust your temps accordingly. Hopefully you can hear your fans turning on when your driving and the temp is over 200* or your fans aren’t working properly. Check fuse/relay.

Having said all of that, if you haven’t changed anything at all, and this is a new and unrelated problem - either your tstat is frozen shut, or your water pump took a dump. I think you may be able to tell which by checking the temp of the coolant hoses going to the rad and leaving the rad. If they’re both the same temp (according to your hand or a thermometer) then I would think that your WP isn’t keeping up and you may have lost some blades. If there is a significant delta between the 2, your tstat is frozen…

More importantly, that’s an awesome song on an amazing album.

Gonna keep the music off on the ride home and keep an ear out. I know the fans come on, just don't know when, they are definitely at full blast by the time I pull into the garage.

I would go with a 180 if I had a tune. My 180 from my daytona threw a code on the Hellcat. I have a Milodon

Was your fans on or air on? I have noticed before if I have my A/C on which the fans are running it will stay at 203

No A/C, what I will try is re-flashing the PCM. Maybe the A/C got put in a bad state recently. I also used the cool down features of the Tazer at the track.

How long has the thermostat or tune been loaded?
The bleeder hole on the top needs to be on the top.
Go 180. I wouldn't go 160 as these engines are designed to run at some sort of operating temp.
Your fans should be screaming if it is truly stuck closed.

Thermostat and the tuning have been in since 2020, I did the initial tune myself and set the fans correctly. https://www.hellcatforum.org/threads/thermostat-tuning.6884/

Another possible issue is the thermostat you bought isn't flowing enough coolant. I know HHP even stated on the other forum in one of their posts their brand 180 tstat sometimes doesn't flow enough coolant on hellcats and they recommend the Mishimoto Racing 180.
Post #12 it was very honest for them to post something like that.
https://www.hellcat.org/threads/180-thermostats.15720/

I just ordered a new one, if this one also goes, the next one will be a Mishimoto.

I don't know......I'd have to think about it....think about it...think think think about it......

There may be a whole generation who don't know about Limp Bizkit...

Apologies to everyone, it is a 180 thermostat, I think I said 185 in original post.

 

[vortecd]

My 180 would run at 185

 

[HWDan]

I swear by the Motorad 332-180. I've had one in the 5.7 for over a decade working perfectly and it's dimensionally identical to the OEM but 180 degrees (still the same form-factor for 5.7/6.1/6.2/6.4 right?)

Might be hard to find now, not sure. It's original for 90's GMC Chevy C1500/C2500/C3500 or something like that.

 

[fumanchu182]

Have tools, use tools... Decide to setup a quick graph to log the fan pwm, fan speed and ECT to see if anything was amiss in the tune. 100% not the tune. As expected when I sent my tune to OST for refinement, I had the fans kick on at 185F in which they did.



Then an interesting anomaly at 192F the thermostat struggle bused, opened and then closed again it looks like:



Then from there the bleeder valve in the jet (at tdc) was able to prevent total meltdown. Waiting for the car to cool down to pull it. Gonna toss it in some 185 degree water and see if the filament moves. If not, then something else might be amiss like the pump, car is down, I repeat we have a code red, car is down!

 

[Magnified]

If it was stuck closed, wouldn't your temperature just continue to go up as you ran the car? Either way I think you are stuck having to replace it just due to the uncertainty of it all...

May not be opening fully...

 

[Whatknot]

Remember modern day engines are designed to run hotter to. The old days of your grandparents car running lukewarm are not how they are designed today. 203F really is not that hot at all.

 

[Catless]

Remember modern day engines are designed to run hotter to. The old days of your grandparents car running lukewarm are not how they are designed today. 203F really is not that hot at all.

All my old '60s Pontiacs had/have 195 F thermostats from the factory so that is not much different. 1950s engines typically 160-180F.

 

[Whatknot]

All my old '60s Pontiacs had/have 195 F thermostats from the factory so that is not much different. 1950s engines typically 160-180F.

True!

But some people are still thinking back to when water temps only ran 175 ish. High temps also use to rapidly break down the oils used back then, most of us run synthetic oil in our cars today, and thus they are much more heat tolerant.

 

[Mean Cat]

So after my last few passes at the track I noticed the car was not cooling down to the usual 192 degrees after a pass. I have a Jet Performance 10183 thermostat. While driving today, 66 degrees out, the car would not get cooler than 204 degrees. So a couple of things I’m thinking may be the culprit.

1. Mechanical failure.
2. Tune somehow has fans set for 204.
3. Air bubble.

I’m ruling out #3 because this would have surfaced a long time ago… And I can’t see if #2 is the culprit as the tune is opaque from OST… if the thermostat is stuck, does anyone have any recommendations and should I go with a cooler thermostat if I have to replace it?

View attachment 47381

Same thing happened to me, it's the T stat, I pulled mine out & put it in boiling water & it never opened & I couldn't push it open either.

 

[Stormtrooper1320]

Same thing happened to me, it's the T stat, I pulled mine out & put it in boiling water & it never opened & I couldn't push it open either.

That's cuz you gotta put this stuff in the water to soften it up

 

[Mean Cat]

Get one ( 180 t stat ) from the local auto parts, cheaper & just as good, with 1 year warranty.

 

[Mean Cat]

That's cuz you gotta put this stuff in the water to soften it up

View attachment 47470

yummy, now I'm hungry