Which trans temp to watch?

[MojaveJoe]

So....I just installed my Edge Insight CTS2 and noted that it has a trans fluid temp coming from the ECU available. A couple days later I hooked up my new trans pan fluid sensor (MagHytec Double Deep pan) and noted that the two temps were 25-30F different most of the time, after 20 miles or so.
The computer temp is always higher 25-30F, so I assume it is measuring the fluid temp as it exits the trans.
The pan temp is being measured midway down in the sump of 3-4 gallons.
So is it safe to say I should be watching the higher temp of the fluid coming from the trans, especially when towing heavy?
Any and all advice and experiences welcome.

 

[DavidC]

Mine is reading the output showing how hard the trans is working. Fluid in the pan is not as important.

 

[cerberusiam]

They are reading the same location, just the accuracy is the difference. The CTS always reads the OE sensor way higher than it should, not sure if that is just the CTS or the OE sensor as other gauges that read it are also off, usually higher than a good analog gauge. Since you already have a pan temp you should move the trans temp sensor to the cooler output line for proactive driving.

 

[MojaveJoe]

Just did 5000+ mile trip towing 12000 lb fiver cross country. Had OEM and Trans pan sensor showing on my CTS2. They were consistantly around 20 degrees different. Trans Pan sensor lower all the time. The OEM sensor never went over 200F, while pan temp was about 180F, so I never feared trasn fluid over heating. I love my CTS2, as it saved me a lot of stress telling me everything I was monitoring was doing fine. Rarely got EGTs ovre 1450F, and that was only for a minute or two pulling a hill.Tried to keep them below 1250F all the time. Thanks to those who pointed me in the Edge direction.

 

[Ozymandias]

OEM sensor is located inside the transmission, your sensor is in the aluminum pan, the would explain to me why there is this little difference in reading.

 

[AH64ID]

Rarely got EGTs ovre 1450F, and that was only for a minute or two pulling a hill.Tried to keep them below 1250F all the time.

I’m assuming (and hoping) stock injectors and tuning??

If so ignore the normal 1250° rule as that doesn’t apply to stock tuning on a 04.5-07 5.9.

 

[MojaveJoe]

Yes... all stock injectors and tuning. So what is the generally accepted EGTs for my engine?

Ozymandias...I agree. Glad I didn't see any higher trany fluid temps when pulling hills

 

[cerberusiam]

As long as the TC is locked you won't see a lot of heat in the transmission. It will run about what ECT is. Where you will see the difference in probe location is in fluid coupling, the pan will show a lot less rise than the cooler line and you will have less time to adjust driving.

 

[AH64ID]

1450° isn’t uncommon for stock tuning.

 

[Turbowski]

Stupid question for yall,

I am getting ready to install my trans temp gauge tonight or tomorrow and the kit comes with the T-fitting. now what line do I cut and put this fitting on? is it the top line coming from the tc cooler? or the bottom? Thank you

 

[cerberusiam]

Which ever line is the fornt cooler line from the transmission. It will have the rubber section in it.

 

[AH64ID]

Have you seen the ISSPRO clipsense?

 

[DavidC]

Have you seen the ISSPRO clipsense?

Mine is measured right out of the transmission with a line Chrysler use to sell in the day with a bung on it. It can get scary at times when you see 230 degrees.

 

[WalterJ]

They are reading the same location, just the accuracy is the difference. The CTS always reads the OE sensor way higher than it should, not sure if that is just the CTS or the OE sensor as other gauges that read it are also off, usually higher than a good analog gauge. Since you already have a pan temp you should move the trans temp sensor to the cooler output line for proactive driving.

Didn't you mean to say "...cooler input line..."?
On this topic much earlier in my trucks' history, I was advised the trans temp sensor is in the valve body, monitoring some flow passage, and was not necessarily represented the "hottest" oil/fluid. My former Banks display reported the ECM data, which I presume was from the aforementioned valve body location.

Wally

 

[cerberusiam]

Line to heat exchanger is a better description. It is a trans cooler output line when looking at it from the trans side. Semantics.

Factory trans temp reading is from the combo transducer that also does gov pressure. It is mounted tot he governor housing on the VB.