super diesel

<<<< Under Pressure
It wasn't on that 93*F day was it Dustin? I've been watching the temps carefully (the coolers not hooked up at the moment for testing) and have noticed that the oil temps will EASILY climb 10-20*F+ or more depending on what your doing with the A/C on over driving without it. All I can say is, thanks GM for that PUNK of a heat exchanger and cooling system. :thumb:
 

moss

<--good vibrations
Dec 15, 2008
296
0
16
43
sandwich, il
It wasn't on that 93*F day was it Dustin? I've been watching the temps carefully (the coolers not hooked up at the moment for testing) and have noticed that the oil temps will EASILY climb 10-20*F+ or more depending on what your doing with the A/C on over driving without it. All I can say is, thanks GM for that PUNK of a heat exchanger and cooling system. :thumb:

thanks for the info mike. i pressure washed my cooling stack out a couple of weeks ago, and have noticed that my oil temp had gone up about 10ish degrees. thought i pushed all the bugs out of my intercooler onto my radiator. but was also about the same time i had to turn the ac on!! however, regular driving unloaded i see about 199 from 75-95 degrees outside. cant complain yet i guess....brad penn earl
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,691
5,848
113
Phoenix Az
well i can say i was pleasantly surprised on mine. thought it would get hotter than it did. pulled the trailer loaded this weekend for our trip. took it easy on the way up as my buddy was haulin his sami with his 08 1500 5.3 ec/sb. His truck would start to hit 230 degrees half way up black canyon city hill. it was 95* out that mornin. We slowed to about 35mph so his truck wouldnt get hotter. I dont think his factory electric fans are able to keep up with a 5,000lbs load on the back. Anyhow, at that speed, temps never went over 230* pullin the hill. That was with a few short burst of WOT just to mess with my buddy and see how it pulled it. average temp cruising in the hills was 220* in 5th gear at 65mph. Coolant temp stayed at 200*.

on the way back we hit verde hill which is 6% all the way up for about 4 miles and 6.5% 1 mile from the top. temp was 80* out leaving the camp spot. hit the hill at 210* oil temp and 200* coolant. dropped to 4th off the bat and ran at 65mph. oil temps climbed to 240* and stayed as we climbed the hill and coolant was 200*. half way up, everyone slowed to 40 due to a trucker that decided to race another one up the hill so i lost momentum. got back in it and got back to 60mph before we hit the steepest part. oil temp hit 255* and coolant was 210*. i tried rolling into it more in 4th to see if i could gat back to 65mph without making temps rocket but wasnt happening. coolant shot to 230* and oil hit 265* in 4th. dropped to 3rd gear and ran 55mph up. coolant dropped back to 210* by the time we hit the top and oil dropped back to 255*. once over the hill, coolant went back to 200* and oil dropped to 225*. on the little hills pullin at 70mph in 5th oil temp would peak 240* and never go over and would drop right back to 225* once over the little hill. i tried a few times gettin on it in 4th to see if temp would climb over 240* with coolant at 200* and it wouldnt. coolant had to raise in temp for me to get oil temp to raise from there. once we hit town it was 100* and oil/coolant temp ran the same at 200* and 225*.

this was with the 12k on the back, the same 500hp tune with timing adjustments for more MPG, a/c on the whole time, and the fan running about 80% of the time (it ran the whole time up the big hills). Oil pressure never dropped below 45psi at 1800rpm at 265* and would climb back to 50psi at 240*. at 225* i was at 55psi. oil pressure was waaaaay better than it was before the built motor than before running the same.
 

super diesel

<<<< Under Pressure
Good info and thanks James. Glad it didn't get any worse. Still I don't like those temps on the hill but what can you do. Oil pressure is good (seems every thing is tight).

I'm about ready to do some testing with the camper (13,100lbs full truck and empty camper on cert CAT scale) and boat (6900lbs empty on CAT scale) up the grades to see what I can get it to. Got derailed though for the moment due to uncontrollable circumstances. Should be able to do some testing latter this week or weekend. It's been upper 80s and low 90s lately.

P5290430.JPG
 

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JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,716
779
113
Texas!!!
Still been keeping a pretty good eye on temps. Especially since it has been getting hot, and I have been doing more towing lately. Here's what I saw today.

OAT: ~95
Terrain: rolling hills
Roads: highway
Speed: 70
RPM: 1750
A/C: of course

Empty
Weight: ~7200
Coolant: 190-192
Oil Temp: just a tick under 220
Oil Pressure at cruising speed: ~39
IAT at MAF: 98
IAT at bridge into heads: 113
EGT: 700 on flat 900 on hills

Loaded (hauling the van on a bumper pull car hauler)
Weight: ~15000
Coolant: 190-200
Oil temp: just a tick over 230 could climb to almost 240 on hills
Oil pressure at cruising speed: ~35
Oil pressure at idle: ~19 (forgot to check when I was unloaded, but by the time I had stopped, my oil temp had already dropped to 220)
IAT at MAF: forgot to check, but assume the same as before
IAT at bridge into heads: 117
EGT: 900 on flat 1000 on hills

I just recently changed my oil and went to Royal Purple synthetic 15W-40. I saw pretty much the same temps with the Delo 400 15W-40 I drained out. Obviously the hills are nowhere near as severe as what you guys see. The steeper ones are pretty short and the longer ones aren't so steep. The steepest and longest hill stabilized the oil temps about half way up.
 

S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
There is some good information with experiences but the biggest question for me is where to get the parts for the cooling upgrades. I haven't read the whole thread so excuse me for not finding it here.
 

super diesel

<<<< Under Pressure
Thanks for the good input Josh.

S. Phenney, the best thing you can do right off the bat is get a good oil temp gauge installed and put the sensor in the location that is indicated in post #57. I use a digital Shindy water temp gauge. Their oil temp gauge is the exact same but with a few more unneeded fittings and cost slightly more because of this. Just use a good gauge. The adapt for the oil supply and fittings are from www.summitracing.com . The adapters I modify to get full oil flow through them (on the very small side stock). They have T-stats in them to control when the oil flows to the cooler or not. P/N:
EAR-503ERL.
The fittings to adapt it to the lines are P/N:
585112ERL.
The 12AN connectors off of them need to be 120* fittings (2pcs needed). Now you can go with either high temp rubber hose like I did or the SS braided. These fittings will depend on that.
I use a Fludyne DB30618 cooler and the fittings are 12AN on both sides. One is a 120* fitting the other is a 150* fitting to the oil lines.
To mount the cooler you will need to be creative till we come up with a common mounting system. I'm working on this but it's been slow unfortunately (time restricted).

I do keep a extra hose section with slices in the truck for the extremely rare chance of a hole or tear. I also keep a set of 12AN plugs to cap off the cooler lines and I can remove the filter adapter to return it to stock if needed. These are safety precautions only.
 

DougSmith

New member
Any oil with PTFE in it will hold heat. Hence the reason that Teflon is used for skillets and pots and pans. Most top end Synthetics use PTFE to make things slicker at a trade off of heat. Once PTFE gets hot it takes a long time to cool off no matter how many coolers are installed.

Sorry for posting again. Just wanted to make sure everyone understands why some oils run hotter than others.

Sent from my PC36100 using Tapatalk 2
 

super diesel

<<<< Under Pressure
Just got back from my test with the 20K load up over Eisenhower tunnel. OHHHHHH MAN! What a trip. First time I've been able to keep it pinned to the floor most the trip and on ALL the grades (low power tow tune the whole time). The OATs were 77*F all the way to 56*F at the tunnel (11K elevation so what do you expect).
These were all recorded with the Fluidyne cooler and it's ducting, Schaeffer 9000 oil, and spraying the intake and cooler at 150psi with the chiller set at 15psi to activate (which was quite frequent and REALLY kept the EGTs and oil temps in check). It worked wonderfully!

At the C470 turn off (bottom of grades) oil temps were at 218*F
Genessee oil temps were at 235*F
East side of the tunnel, oil temp was 235*F as well.

I had a head wind most the way up of 20-25mph (pretty strong), and the water temp never budged from 195*F the entire time (so much for a bigger radiator fixing our problem).

I found I had consumed all the water from the tanks on the run up there so I refilled for the return trip. Now comes the big test. West side of the tunnel.

I was able to keep it pinned for about half way till the shear angle and alt robbed my power and speed. I had to shift to 3rd and hold it at about 60mph the rest of the way. Oil temps were at 246*F by the time I reached the tunnel. ECT was still at 195*F as was the trans that never wavered.
I run up another grade called Floyd Hill (short but steep) without the water to see what would happen. Oil temps climbed very quickly from 185*F at the bottom to 238*F and climbing FAST at the top. Interesting.

All in all,,,, I think the water spray kept things down more that I think they did. This test was NOT run with A/C on which I'm sure WILL drive those temps another 10-15*F higher min.

Makes me wonder about the temps without the cooler and set up I have now. It's scarrrrry to think for me.

Remember, I had a 20K total load today (truck included).

Tried to tell some folks over at "THE PLACE" :rolleyes: about these findings where there pushin a big radiator instead :rofl::roflmao: . One of them told me to go peddle my snake oil some place else. Some folks are so blind you cant even spell it out for them and continue to support and spread miss-info at all costs. This is very important to be relayed that a larger radiator will keep the TOP end of the motor cool. It WILL NOT cool the oil and everything that is being cooled and lubed inside. An oil temp gauge will tell you this right off the bat. This is why the gauge is important.
 

chevyburnout1

Fixing it till it breaks
Aug 25, 2008
2,368
1
38
Berthoud, CO
Wow great results getting posted here. I can't remember how many times I've pulled the west side of Eisenhower with the pedal to the floor racing my cocky Cummins friend up it with our campers. I don't even want to think what my temps were.... But got the gauge installed so hopefully camping here in the next few weeks. Hope to add to our findings.

77E46A02.jpg
 

chevyburnout1

Fixing it till it breaks
Aug 25, 2008
2,368
1
38
Berthoud, CO
I've gotten a little more easy on my road trips, since the drive there is sometimes half the fun with us. But I'll definitely see what results my old driving habits will create. A buddy that always goes with us just recently upgraded from an '04 Powerstroke to an '03 Cummins and now he likes to run 70-75 all the way up the pass if he can.

I do know messing around on the interstate with the a/c on I've already seen oil temps hit 220°F
 

moss

<--good vibrations
Dec 15, 2008
296
0
16
43
sandwich, il
what are you using to see the air temp at the bridge? if not a tech 2, anyone know how to get to that info on a tech 2? thanks

Still been keeping a pretty good eye on temps. Especially since it has been getting hot, and I have been doing more towing lately. Here's what I saw today.

OAT: ~95
Terrain: rolling hills
Roads: highway
Speed: 70
RPM: 1750
A/C: of course

Empty
Weight: ~7200
Coolant: 190-192
Oil Temp: just a tick under 220
Oil Pressure at cruising speed: ~39
IAT at MAF: 98
IAT at bridge into heads: 113
EGT: 700 on flat 900 on hills

Loaded (hauling the van on a bumper pull car hauler)
Weight: ~15000
Coolant: 190-200
Oil temp: just a tick over 230 could climb to almost 240 on hills
Oil pressure at cruising speed: ~35
Oil pressure at idle: ~19 (forgot to check when I was unloaded, but by the time I had stopped, my oil temp had already dropped to 220)
IAT at MAF: forgot to check, but assume the same as before
IAT at bridge into heads: 117
EGT: 900 on flat 1000 on hills

I just recently changed my oil and went to Royal Purple synthetic 15W-40. I saw pretty much the same temps with the Delo 400 15W-40 I drained out. Obviously the hills are nowhere near as severe as what you guys see. The steeper ones are pretty short and the longer ones aren't so steep. The steepest and longest hill stabilized the oil temps about half way up.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,716
779
113
Texas!!!
what are you using to see the air temp at the bridge? if not a tech 2, anyone know how to get to that info on a tech 2? thanks
LB7s and LLYs don't have a sensor there. GM started putting a sensor there with the LBZ.
 

super diesel

<<<< Under Pressure
Good posts in there Brian.

Josh, your putting down some really well informing info.

Thanks guys.

The simple fact that the coolant does not touch the internals to help cool them and only cools the upper part of the motor escapes some folks. Cool the internals,,,,,,,and your there. :hello: