• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Dodge, Jeep and RAM Forum dedicated to FCA owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the SRT Forum today!

Thermostat potentially may be stuck closed…

fumanchu182

500 Posts Club
Premium Account
Active Duty U.S. Navy
Donating Member
10 Second Best E/T
Member ID
#2366
Messages
839
Reactions
1,971
Points
132
City
Pasadena
State
MD
Country
United States
Vehicle
2015 Challenger SRT Hellcat
#1
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?

875EFF8C-F8C3-4A74-BDE2-590F481FE716.jpeg
 

EricG

500 Posts Club
Member ID
#1385
Messages
713
Reactions
1,168
Points
132
City
Albuquerque
State
NM
Country
United States
Vehicle
'19 Hellcat Redeye
#2
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

1000 Posts Club
Founding Member
Member ID
#966
Messages
1,709
Reactions
3,310
Points
162
City
Buffalo
State
NY
Country
United States
Vehicle
2016 Dodge Charger Triple Black
#3
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. :cool:
 

vortecd

Poster Club Hall of Fame
Premium Account
10 Second Best E/T
HFCOTM
Member ID
#1248
Messages
12,382
Reactions
32,086
Points
402
City
Middleville
State
MI
Country
United States
Vehicle
2016 Charger Hellcat
#4
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

500 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#4957
Messages
844
Reactions
2,077
Points
182
City
Martin
State
MI
Country
United States
Vehicle
2018 Challenger Hellcat
#5
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

500 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#4957
Messages
844
Reactions
2,077
Points
182
City
Martin
State
MI
Country
United States
Vehicle
2018 Challenger Hellcat
#6
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

7000 Posts Club
Founding Member
Premium Account
U.S. Marine Veteran
Member ID
#1068
Messages
7,654
Reactions
20,710
Points
352
City
Baltimore
State
MD
Country
United States
Vehicle
2019 Challenger 1320
#7
More importantly, that’s an awesome song on an amazing album. :cool:
I don't know......I'd have to think about it....think about it...think think think about it......

:p
 

EricG

500 Posts Club
Member ID
#1385
Messages
713
Reactions
1,168
Points
132
City
Albuquerque
State
NM
Country
United States
Vehicle
'19 Hellcat Redeye
#8
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...
 
OP
fumanchu182

fumanchu182

500 Posts Club
Premium Account
Active Duty U.S. Navy
Donating Member
10 Second Best E/T
Member ID
#2366
Messages
839
Reactions
1,971
Points
132
City
Pasadena
State
MD
Country
United States
Vehicle
2015 Challenger SRT Hellcat
Thread Starter #9
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. :cool:
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......:p
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

Poster Club Hall of Fame
Premium Account
10 Second Best E/T
HFCOTM
Member ID
#1248
Messages
12,382
Reactions
32,086
Points
402
City
Middleville
State
MI
Country
United States
Vehicle
2016 Charger Hellcat
#10
My 180 would run at 185
 

HWDan

Active Member
Founding Member
Premium Account
Member ID
#1183
Messages
456
Reactions
1,148
Points
117
City
Home of the Hellcat
State
Non-US
Country
Canada
Vehicle
2017 Charger SRT 392
#11
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.
 
OP
fumanchu182

fumanchu182

500 Posts Club
Premium Account
Active Duty U.S. Navy
Donating Member
10 Second Best E/T
Member ID
#2366
Messages
839
Reactions
1,971
Points
132
City
Pasadena
State
MD
Country
United States
Vehicle
2015 Challenger SRT Hellcat
Thread Starter #12
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.

1624480083182.png

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

1624480260974.png

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

6000 Posts Club
Founding Member
Member ID
#1155
Messages
6,686
Reactions
12,206
Points
352
City
West Texas
State
TX
Country
United States
Vehicle
2017 Charger HC
#13
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

1000 Posts Club
U.S. Army Veteran
Member ID
#6510
Messages
1,235
Reactions
5,253
Points
162
City
nearest is Portland, but live in the country
State
OR
Country
United States
Vehicle
Ford Mustang GT convertible
#14
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

Active Member
Member ID
#1407
Messages
100
Reactions
179
Points
37
City
Parkersburg
State
WV
Country
United States
Vehicle
2015 Hellcat Challenger
#15
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

1000 Posts Club
U.S. Army Veteran
Member ID
#6510
Messages
1,235
Reactions
5,253
Points
162
City
nearest is Portland, but live in the country
State
OR
Country
United States
Vehicle
Ford Mustang GT convertible
#16
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

3000 Posts Club
Founding Member
Donating Member
9 Second Best E/T
HFCOTM
Member ID
#997
Messages
3,205
Reactions
5,983
Points
302
City
Houston
State
TX
Country
United States
Vehicle
2017 Challenger Hellcat
#17
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

7000 Posts Club
Founding Member
Premium Account
U.S. Marine Veteran
Member ID
#1068
Messages
7,654
Reactions
20,710
Points
352
City
Baltimore
State
MD
Country
United States
Vehicle
2019 Challenger 1320
#18
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 :ROFLMAO:

crab boil.jpeg
 

Mean Cat

3000 Posts Club
Founding Member
Donating Member
9 Second Best E/T
HFCOTM
Member ID
#997
Messages
3,205
Reactions
5,983
Points
302
City
Houston
State
TX
Country
United States
Vehicle
2017 Challenger Hellcat
#19
Get one ( 180 t stat ) from the local auto parts, cheaper & just as good, with 1 year warranty.
 

Similar threads

Latest Dodge SRT Posts



Top