I see on the CTS as I’m cruising along about 75 miles an hour my intake air temperature is right at 100 temperature is at 2:08 and my transmission fluid temperature is at 175 EGT’s about €760 number sound correct to you guys

 

By the way Temperature today is 70

 

Air temp looks right. Mine is usually about 40° above ambient. Trans seems a little high to me though.

 

still getting used to the info I have on the cts so I ask silly questions, I have no real load cept a tool box in the bed , what would consider normal?

pulled this from an old thread


@Bently_Coop
Bently_Coop , 12-16-2015 01:17 PM
Post Fiend
140° +/- is about right. Ambient + 80-100° is where you should be.

 

I have not done the 6.0 cooler mod yet

 

I thought I saw on here once that the reading through the OBD2 port will be 10° higher or more than a gauge plumbed into the pressure access port. I read mine through the OBD2, have the 6.0 cooler and the trans is rebuild but I have seen 170 many times during warmer weather

 

For ambient at about 100 deg, the tranny temp of 175 is not bad, especially w/o a 6.0 cooler. You can add about 60 deg to that 175 and that will be close to your EOT +/-.

 

A long run at 170* AT is a good thing, drives water out of the trans fluid. IIRC trans temp will normally be 80* over ambient once fully warmed up. Sustained trans temp limit is 225* IIRC, at 250* ya better pull over and let it idle till it cools off.

EOT should be close to coolant temp. More than 20* difference would concern me.

 

That’s a good baseline. Nothing wrong with any of those numbers. Watch trans temp when working the truck harder. IMHO, if you’re seeing over 200* you should consider upgrading to the bigger trans cooler.

208 EOT is normal/fine. Expect EOT to be a little warmer than coolant temp (195* with stock t-stat).

Ive given scangauges to LOTS of customers and I tell them to study them for awhile and determine what’s normal for their truck. It’s too easy to see new data and wonder if it’s ok (and call me tooooo many times, lol).

 

Thanks i guess that's what i was wondering , (things being normal) I am considering the trans cooler, and wondering if moving to synthetic oil will bring numbers down or atleast give me more high end room.

 

Neither have I...mine runs about 100 over ambient....and I have no plans to switch to the 6.0 trans cooler.

 

No harm in bigger cooler, but I tell my people not to bother if they don’t have a problem. It’s hard to argue that anything is more reliable than STOCK.

The only advantage to synthetic oil is the ability to run a longer oil change interval. The engine wear (based on UOA’s) is the SAME for good conventional oil and high $$$ synthetic oils until you exceed the recommended OCI. Most people see good results with conventional oil using 5k mile OCI. Synthetic oils often go out to 7500 miles or sometimes more (depending on the way truck is used) before seeing increased wear. The synthetic oil manufacturers are marketing geniuses and have convinced a lot of people there is other magic at play. It’s possible some of those people will comment on the superiority of their favorite brand of expensive oil.

 

For some reason I'm thinking that 90+- over ambient is normal and I would consider a 10* variation of that reasonable. If I'm wrong I'd like to be advised as such.

 

I think the 60, 80, 90, etc above ambient is good rule of thumb depending on ambient. I’ve seen that rule of thumb, when ambient is on the very high side also creep higher to match the gauge tranny temp, including heavy towing.

 

The fellas above have some great information for you regarding readings, historical data and observations. Although, you MUST establish a baseline for your vehicle, which I believe that is what you are doing now. I have some screenshots saved to 3 different devices of "good running conditions". Cold idle, hot idle and at speed. These are for comparison and reference sake because if/when there is a problem the last thing I wan to do is second guess myself. The second to last thing I want to do is compare my conditions to someone else that has not been close, ever...

There are general guidelines and hot/cold milestones, but when you get to the specifics your truck is different than most other trucks on this forum.

Here is an example of one of the screenshots I keep on file.




As for your questions regarding oil and what synthetic may bring to the table. This topic has been beaten to death, but is still relevant in modern times due to FTE'rs new and old not knowing the details within the archived threads. I don't mind discussing the facts and science behind oils and the choices we have available to us. If I/we can help just one person come to a conclusion about which oil or type of oil is right for them, then repeating the numbers and science behind the studies is worth it, 100% and absolutely.

That said, I have concluded I will be taking a course of action similar to what our friend Eric has done. His UOA thread (specifically post #11 and onward) gave us some insight into what works for his 7.3L. The numbers don't lie, like some of the marketing people do. He recently purchased 50+ gallons of Travelers 15w40 from TSC after running Triax Fleet Supreme (full synthetic boutique oil).

I have 4 gallons of Triax Fleet Supreme in the oil pan of my truck with 5,500 miles of heavy towing on it. I have an empty Blackstone Laboratories bottle on my work bench. I will send the Triax off, then Rotella T6, then Travelers 15w40. I have been running Rotella T6 for 8 years without any concern. I tried the Triax because I got it for a great deal and NOT at boutique oil prices. If I can get the same level of performance from Travelers oil, not have to mail order it and pay 40% of the cost (60% discount) as the synthetic oils, I'm in.

You have had your head deep into this truck for a little while now and I hope you are learning a lot and enjoying the process.