super diesel

<<<< Under Pressure
Thought I would start a new thread on this and it's importance. How many have been watching and regulating the oil temps in these trucks? What have you seen in stock mode and/or higher tune modes (list configuration of motor mods with stock turbo, twins, triples, dual fuelers, towing what weight, or what have you). I myself have seen that the factory set up is barely up to par (actually found wanting) in the stock tuning with an empty truck and single charger. The thread "oil temp with twins" can be referenced for info as well. Let us know your findings please.
 

moss

<--good vibrations
Dec 15, 2008
296
0
16
43
sandwich, il
just got mine installed on a stockish 08. running brad penn oil. havent seen it loaded yet, but crusing empty is about 190ish. i will out more in the summer towing my puller
 

hondarider552

Getting faster
May 28, 2008
10,628
2
36
33
Arizona
Here are my thoughts;


LB7's are more prone to higher oil temps, why, I am not 100% sure, but it only seems like fluctuating oil pressures are tied to the LB7's..


I never did any oil testing in my LBZ when I had it, mainly because I didnt know much about the topic either, but, when I would tow 14k to the dunes (weekend warrior full throttle) engine fan would kick on about 230* ECT, im sure oil temp was through the roof. I wish I did testing on it.


On my LB7, I knew oil temp with twins was an issue. I bought my truck knowing it "overheated" while towing, which was true, but it wasnt the coolant that was overheating, it was the oil. To test this, I towed my 26' gooseneck that is 5k lbs, up to northern AZ, from 1300' to over 7k. Results shocked me. Oil temps ski rocketed to over 260* pre OEM cooler, while climbing in 4th gear at 60 mph to keep the EGT's in check, coolant fan came on once, then back off. Stock trans cooler, and no additional oil cooling, other than stock. Reason why it was overheating the coolant. In that case, the hot 260*+ oil was preheating the engine coolant from the cooler, offloading it's heat into the coolant. Now my engine had to deal with that, as wel as higher temp coolant fromt he engine working harder, and it only got worse the higher the oil temp got, then oil pressure gauge would go :dancenana: from 30-65psi.

Bought Killerbee engine oil cooler, "new used". Oil changes are now 14 qts. Hooke dup trailer, same route there and back, same trailer. Never got over 190* oil temps, again, pre cooler. Engine fan never came one, but efi showed 195*, normal. Cool, it works. To put into a BTU perspective, my cooler is 140,000 BTU's.


This past weekend I towed 1000 miles a CC/SB LB7 to Mike L's. There is a 17 mile grade from Palm Springs, CA back into AZ, and wery windy at times. I was towing ~14k. 55mph in 4th gear up the hill, for 10+ miles, coolant reached 210*, oil reached 220*, again, for 10+ miles. The one thing I noticed with oil temps vs EGT's, is that if you lug the engine up the hills at 1900-2200 rpm egt rises, but oil temp does not. I felt it was easier to downshift into 4th gear to aid in higher boost and lower EGT's' but oil temp would rise, kind of a tradeoff, as you can't have both with big twins.

Around town my coolant never goes above 180*, and slows warming up around 164-175*. Oil temp sits are 180* no matter what, unloaded, and now loaded on flat ground. Your going to make heat period on the hills, but a biggert cooler cannot possibily stop rising oil temps, but it does help "cusion" the spikes. 220* is still hot, but for the load I was towing, combined weight, and air temp, that was cake for my engine. I only have about 2300 miles on this cooler, but I would spend the money again, but only if Super Diesel made a kit. :thumb: BTW, I have MPI big twins, 366/480, 30% injectors, stock CP3.
Sorry for the novel, just wanted to share my findings. :thumb::thumb:
 
Last edited:
  • Like
Reactions: Harshman

super diesel

<<<< Under Pressure
Thanks for the input Brian and thanks for the kind words. I just wish I was smart enough to post and bring this to light years ago. I'm sure that it will get more interesting as the summer roles in and those that are running oil temp gauges post there findings. Any one running coolers, please post pics if you can and what type, and those running gauges, please post what gauge. I'm quite sure those running gauges for this have a piece of mind to be able to regulate this. There are articles on how the high temps can extremely reduce the life of these vehicles, not only just through oil breakdown but through high wear because of the higher temps there running that makes the parts expand past the design specs making the tolerances much tighter thus less oil film jacket to protect it. Optimum oil temp is around 180* to 210*F. I'm convinced that there are WAY more folks running much higher than this as a constant diet, and aren't aware of it. I will be putting a temp gauge on the LLY here in about a week and it has a 3K camper on it 24/7 12month out of the year. I'll report back with my findings on it before the cooler system is put on.
 
Last edited:

BHoward6.6

West Coast
Feb 9, 2011
274
0
16
Huntington Beach, CA
With the temp probe mounted in the oil cooler, in the port that is in front of the oil filter out at a angle.
OAT's around 75*
With a 4094avnt, emty 180*, with a large trailer 200*
OAT's 100* with a large trailer 240* and as high as 260*

OAT's around 75*
With a 4094avnt and S475, emty 190*, with a large trailer 215*

I have not towed with the twins in hot weather.

Where is the perfect place to install the oil temp probe?
 

hondarider552

Getting faster
May 28, 2008
10,628
2
36
33
Arizona
There is a hex 10 mm alllen plug on the top side of the oil filter assembly, you can only get to it from the driver fenderwell, and it's on tight as ****. Under the exhaust manifold, I will get a good picture tomorrow. This reads the hottest oil coming form the engine. I do not care so much about oil coming back to the engine, I want to see whats coming out :thumb:

Brandon, "turbotug" helped me a lot on this issue, I owe him a lot!
 

Turbotug

BEER SLAYER
Sep 3, 2006
1,019
1
38
45
Phoenix
I've had my TD-EOC installed since May of '07...oil temp gauge installed well before that.

My findings are pretty much exactly what Brian posted above. I believe my experience with oil temps, towing, and the oil cooler are what prompted Brian to buy. ;)

I've also done the "Taurus fan mod" on my truck. In the winter months I tow a 37' GN Toyhauler to the dunes in Southern Cali. It is in my opinion that the addition of the oil cooler that allows me to pull such a large load thru the grades and back with out a coolant temp issue.

I have posted pretty extensively (with more detail) about my findings regarding this subject on this board in the past. A quick search should give you a bit of reading..:D
 

super diesel

<<<< Under Pressure
I remember Brandon. There has never been enough light and reality shed on this. Your findings should have much more attention. It should be made a priority for those wanting a full life from there Dmax. I am also questioning as to how much of a part this may play in spun mains and to some degree the broken pistons on the LBZs that are being pushed hard. Maybe I'm way off, but I don't think it's helping the situation one bit.
 

hondarider552

Getting faster
May 28, 2008
10,628
2
36
33
Arizona
Exactly what I was thinking Michael. Thought for a few mins it would help LBZ/LMM pistons some, but I do not think it will, although Ive never hooked up a gauge to a bone stock truck before.
 

lddrew

shootin for 13's
Jan 10, 2011
216
0
0
West Georgia
This is already shaping up to be a great thread. thanks to all who are contributing to it

Here are my thoughts;


LB7's are more prone to higher oil temps, why, I am not 100% sure, but it only seems like fluctuating oil pressures are tied to the LB7's..


I never did any oil testing in my LBZ when I had it, mainly because I didnt know much about the topic either, but, when I would tow 14k to the dunes (weekend warrior full throttle) engine fan would kick on about 230* ECT, im sure oil temp was through the roof. I wish I did testing on it.


On my LB7, I knew oil temp with twins was an issue. I bought my truck knowing it "overheated" while towing, which was true, but it wasnt the coolant that was overheating, it was the oil. To test this, I towed my 26' gooseneck that is 5k lbs, up to northern AZ, from 1300' to over 7k. Results shocked me. Oil temps ski rocketed to over 260* pre OEM cooler, while climbing in 4th gear at 60 mph to keep the EGT's in check, coolant fan came on once, then back off. Stock trans cooler, and no additional oil cooling, other than stock. Reason why it was overheating the coolant. In that case, the hot 260*+ oil was preheating the engine coolant from the cooler, offloading it's heat into the coolant. Now my engine had to deal with that, as wel as higher temp coolant fromt he engine working harder, and it only got worse the higher the oil temp got, then oil pressure gauge would go :dancenana: from 30-65psi.

Bought Killerbee engine oil cooler, "new used". Oil changes are now 14 qts. Hooke dup trailer, same route there and back, same trailer. Never got over 190* oil temps, again, pre cooler. Engine fan never came one, but efi showed 195*, normal. Cool, it works. To put into a BTU perspective, my cooler is 140,000 BTU's.


This past weekend I towed 1000 miles a CC/SB LB7 to Mike L's. There is a 17 mile grade from Palm Springs, CA back into AZ, and wery windy at times. I was towing ~14k. 55mph in 4th gear up the hill, for 10+ miles, coolant reached 210*, oil reached 220*, again, for 10+ miles. The one thing I noticed with oil temps vs EGT's, is that if you lug the engine up the hills at 1900-2200 rpm egt rises, but oil temp does not. I felt it was easier to downshift into 4th gear to aid in higher boost and lower EGT's' but oil temp would rise, kind of a tradeoff, as you can't have both with big twins.

Around town my coolant never goes above 180*, and slows warming up around 164-175*. Oil temp sits are 180* no matter what, unloaded, and now loaded on flat ground. Your going to make heat period on the hills, but a biggert cooler cannot possibily stop rising oil temps, but it does help "cusion" the spikes. 220* is still hot, but for the load I was towing, combined weight, and air temp, that was cake for my engine. I only have about 2300 miles on this cooler, but I would spend the money again, but only if Super Diesel made a kit. :thumb: BTW, I have MPI big twins, 366/480, 30% injectors, stock CP3.
Sorry for the novel, just wanted to share my findings. :thumb::thumb:

awesome post brian. I am now really curious about my oil temps on a stock turbo LBZ during the hot summer pulling 7k.

Which gauge do you guys recommend. autometer make one?? thanks

awesome thread, will keep updated on this one for the duration
 

super diesel

<<<< Under Pressure
I know they had a series of pistons that were not the most desirable for a period, but when I did a run up the hwy where there is a hill the other day to test a higher tune (about 200hp over stock) with the gt4202 on, it really alarmed me how rapidly it went out of control. So I can only speculate on the LBZ. This was in the LB7. I'll be curious to see the LLY with the camper and a 80hp+ tune. :eek: I'm guessing I will have to keep it under control.
 

jmaz268

Lead from the Front
May 20, 2010
2,895
0
0
40
Springfield IL
I know me and Brian talked about quite abit before he bought his.

I think addition cooling should be HIGHLY considered with any turbo, that is not coolant cooled as well. I personally wouldn't install twins without buying one. I wouldn't even run the truck with triples without it being installed.

Not trying to scare anyone, but twins and triples, generate ALOT of heat. And with the oil being the only thing soaking it up.....oil gets thinner the hotter. Not good stuff IMO

I think with the multiplication of heat going into the oil by an oil cooled turbo, plus the extra heat/power associated with running such.

I may throw a gauge on my stock turbo LLY and see what temps are like when I tow the truck around. Just to confirm it.
 

jmaz268

Lead from the Front
May 20, 2010
2,895
0
0
40
Springfield IL
I know they had a series of pistons that were not the most desirable for a period, but when I did a run up the hwy where there is a hill the other day to test a higher tune (about 200hp over stock) with the gt4202 on, it really alarmed me how rapidly it went out of control. So I can only speculate on the LBZ. This was in the LB7. I'll be curious to see the LLY with the camper and a 80hp+ tune. :eek: I'm guessing I will have to keep it under control.

about what I'm running too.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,120
4,863
113
Phoenix Az
To be honest, ive overlooked this many a time not feeling our trucks were really that bad. Untill brian made me think twice.

Back before i bent a rod, i towed the same amount of weight brian and i just did to cali (12k). I drove tthe truck pretty damn hard because it was the first big load i had with the twins. I ran a 2400uS tune the whole time. On our way back, i had noticed my oil pressure would drop 10psi if i rolled into the trottle and the tc was locked in 5th. I asked about it onve we got back and was told its normal and that it probably did it on the stock turbo and i never noticed.

Well now i believe different. Ill ne buying a 11ft cab over camper here shortly and a 20ft flat bed. Next on the list is an oil cooler and fuel cooler sufficant enough for my needs.

Id really like to fit both on my custom bumpers skid plate but im more concerned about finding a cooler that will cool pull the heat out of the oil/fuel efficently.
 

Turbotug

BEER SLAYER
Sep 3, 2006
1,019
1
38
45
Phoenix
OOO!!! Thanks for sharing all and some good insightful posts. Any input you have Brandon is always greatly appreciated. Any reason your holding off on the BIG power while towing though? :grd:



J/K :hug:

We don't have the hills in southern Az/Ca that you do in Colorado...:thumb: