Fluctuating coolant temps

[Vinnie1986]

Hey guys, had a quick question here. Yes I've read through previous posts and seen some fixes but wanted to ask anyways. Recently replaced my water pump and thermostat about a month ago. I went with a carquest 203° thermostat ( mistake I know ) anyways the coolant temp has been pretty good fluctuating between 188-199°. Today on the way home driving on the highway I noticed it got all the way up to 215 and stayed there for a bit than finally dropped back down to 192° after I turned the heat on but that could have been a coincidence. Being a mechanic I'm gonna guess and say the thermostat or the sensor might be a little suspect. Any of you guys using a 180° thermostat? Any noticable drop in gas mileage? Was thinking of changing it out for a gates or stant T-stat. Thanks!

 

[Ken226]

Hey guys, had a quick question here. Yes I've read through previous posts and seen some fixes but wanted to ask anyways. Recently replaced my water pump and thermostat about a month ago. I went with a carquest 203° thermostat ( mistake I know ) anyways the coolant temp has been pretty good fluctuating between 188-199°. Today on the way home driving on the highway I noticed it got all the way up to 215 and stayed there for a bit than finally dropped back down to 192° after I turned the heat on but that could have been a coincidence. Being a mechanic I'm gonna guess and say the thermostat or the sensor might be a little suspect. Any of you guys using a 180° thermostat? Any noticable drop in gas mileage? Was thinking of changing it out for a gates or stant T-stat. Thanks!

Is the sensor from CarQuest too?

 

[Vinnie1986]

Is the sensor from CarQuest too?

The sensor is the OEM one I believe

 

[Zoe Saldana]

Hey guys, had a quick question here. Yes I've read through previous posts and seen some fixes but wanted to ask anyways. Recently replaced my water pump and thermostat about a month ago. I went with a carquest 203° thermostat ( mistake I know ) anyways the coolant temp has been pretty good fluctuating between 188-199°. Today on the way home driving on the highway I noticed it got all the way up to 215 and stayed there for a bit than finally dropped back down to 192° after I turned the heat on but that could have been a coincidence. Being a mechanic I'm gonna guess and say the thermostat or the sensor might be a little suspect. Any of you guys using a 180° thermostat? Any noticable drop in gas mileage? Was thinking of changing it out for a gates or stant T-stat. Thanks!

If you ever are concerned about over heating; you can put the heat on to reduce the coolant temperature.

Try that the next time it hits 215 to see if it goes below 200.

My guess it is the thermostat might be inaccurate. Change that first.

 

[caulk04]

I've seen mine spike up a bit like that while it's still warming up and settling in, likely the grille shutters and thermostat finding equilibrium. It'll also drop to 190 when coasting for a bit...

It might just be a little slow. Observe and carry on is my opinion.

 

[Vinnie1986]

I've seen mine spike up a bit like that while it's still warming up and settling in, likely the grille shutters and thermostat finding equilibrium. It'll also drop to 190 when coasting for a bit...

It might just be a little slow. Observe and carry on is my opinion.

Makes sense thanks! Btw I installed one of your bypass kits with the aluminum plug and man it works absolutely amazing!! Dropped the trans temp over 40°!!!

 

[Vinnie1986]

If you ever are concerned about over heating; you can put the heat on to reduce the coolant temperature.

Try that the next time it hits 215 to see if it goes below 200.

My guess it is the thermostat might be inaccurate. Change that first.

Yep I turned the heat on and it did exactly that! Thanks!

 

[Wild one]

Hey guys, had a quick question here. Yes I've read through previous posts and seen some fixes but wanted to ask anyways. Recently replaced my water pump and thermostat about a month ago. I went with a carquest 203° thermostat ( mistake I know ) anyways the coolant temp has been pretty good fluctuating between 188-199°. Today on the way home driving on the highway I noticed it got all the way up to 215 and stayed there for a bit than finally dropped back down to 192° after I turned the heat on but that could have been a coincidence. Being a mechanic I'm gonna guess and say the thermostat or the sensor might be a little suspect. Any of you guys using a 180° thermostat? Any noticable drop in gas mileage? Was thinking of changing it out for a gates or stant T-stat. Thanks!

Both Gates and Stant are owned by Motorad now as far as i know,and they aren't anywhere near the quality they used to be.Always check a new thermostat in a pot of water on the stove,and use a meat thermometer etc. to monitor the temp it opens at.
I ran 180's in my old truck,the wifes last couple of Challengers and my 300 with no issues