Oil coolers on trucks

[Snagglefoot]

I’ve had a few trucks with oil coolers from the factory. One was a 93 Suburban with a 5.7 liter engine with an oil cooler built into the rad. The other is a Chevy 6 liter Gen IV with a factory auxiliary cooler that looks like a miniature radiator (and no, it’s not the AC condenser)

Obviously GM thought it was important the the oil temps be kept within reason. However, I don’t have an oil temp gauge. Does anyone have any observations from from a oil temp gage such as what was their normal temp crushing down the highway vs towing a heavy trailer etc. I might shoot the oil temp cooler with an infra red temp gun during some stops. Your comments are welcome. Thanks.

 

[maxdustington]

My old man had both trans and what I assume was an oil cooler on his 2000 Savana 3500. It disappeared mid 2000s (I assume it was leaking and he just deleted it). Still went 300k km on original motor and trans. He towed some heavy loads: dump trailers full of concrete/bricks/construction debris and 1000Lb+ payloads with probably 1000 pounds of tools and shelves with that thing. That was one of the last years the SBC was offered, I think the 2001 Savana was the last GM truck to roll out of the factory with a SBC.

It looked so [censored] with both coolers visible through the grill.

 

[14Accent]

Lots of those trucks came with oil coolers, especially the early ones. When the LS engines came out, I saw more and more WITHOUT oil coolers. It seems only the trucks with the HD cooling now get a 3 or 4 row radiator and oil/trans coolers built in. There are others that had the style you have, OP, with the cooler out front.

Does it hurt? Of course not. My problem is that I do NOT trust rubber hoses to carry engine oil. I've seen far too many failures. If I had a Chevy truck with oil cooler lines, I would immediately find an oil filter adapter that allowed me to have -AN and stainless braided hoses made. And no cooler in the radiator, of course, all out front of the condenser.

 

[Snagglefoot]

Originally Posted By: 14Accent
Lots of those trucks came with oil coolers, especially the early ones. When the LS engines came out, I saw more and more WITHOUT oil coolers. It seems only the trucks with the HD cooling now get a 3 or 4 row radiator and oil/trans coolers built in. There are others that had the style you have, OP, with the cooler out front.

Does it hurt? Of course not. My problem is that I do NOT trust rubber hoses to carry engine oil. I've seen far too many failures. If I had a Chevy truck with oil cooler lines, I would immediately find an oil filter adapter that allowed me to have -AN and stainless braided hoses made. And no cooler in the radiator, of course, all out front of the condenser.


I had a cooler line leak where it came out of the oil filter boss. It was also soggy at the crimp. The Dorman line had the wrong fittings. Had to get it from GM.

 

[Snagglefoot]

Any one have some sample temps?

 

[clinebarger]

Originally Posted By: Snagglefoot
I’ve had a few trucks with oil coolers from the factory. One was a 93 Suburban with a 5.7 liter engine with an oil cooler built into the rad. The other is a Chevy 6 liter Gen IV with a factory auxiliary cooler that looks like a miniature radiator (and no, it’s not the AC condenser)

Obviously GM thought it was important the the oil temps be kept within reason. However, I don’t have an oil temp gauge. Does anyone have any observations from from a oil temp gage such as what was their normal temp crushing down the highway vs towing a heavy trailer etc. I might shoot the oil temp cooler with an infra red temp gun during some stops. Your comments are welcome. Thanks.

None of the 4.8L/5.3L trucks came with an oil cooler, ALL 6.0L trucks have an oil cooler from the factory.

The GMT-400 trucks are a mixed bag, Even the 4.3L can have an oil cooler.

Express/Savanna vans had Gen 1 SBC's through 2002.

More detail about the 6.0L vehicle with the oil cooler mounted out front? I can't think of one like that off the top of my head.

 

[SHOZ]

You can adapt the oil filter mount type to your existing oil filter if it is a screw on filter type. Just needs some coolant lines ran to it like the heater return.

 

[irv]

I had all the bells and whistle on my 97 Sierra Z-71 SLE and put 144,000 kms on it before I sold it and never any issues with the engine oil cooler nor trans cooler.

The sunshell gear went out of the trans around 140,000 or so but that was common I was told.

Do the newer models still have all these features? I don't believe my 09 Z-71 SLT Sierra had any.

 

[4WD]

My 2017 Tahoe has both oil/ATF coolers and piston jets … my 2010 GMC has ATF only …

 

[LotI]

Try a Scanguage II or scanner.

I use a SGII on my E450 and trans temps are around 190F on a summer day steady state but will rise to 210F when climbing or under repeated acceleration.

 

[Lolvoguy]

Originally Posted By: 14Accent
My problem is that I do NOT trust rubber hoses to carry engine oil. I've seen far too many failures.


The oil cooler lines on my BMW are now 30 years old and STILL have not leaked.
Same goes for the PS fluid lines and pump.

 

[BrianF]

There is no sending unit in my Tb but my old 2011 Ram 1500 had one for the oil. Not sure if it was an actual sensor or some algorithm based measurement (so they say for the Cummins). The 1500 I don't think had an oil cooler, well I never saw any lines plumbed for one. The temp would hold around the 90's C when unloaded after some time on the highway. I could get it to 115C when towing heavy. It took a while to drop as well. The trans and coolant could sustain decent numbers though.

My 3500 has a liquid to liquid oil cooler. It maintains mid 90's C when unloaded and I have had it peak at 100 or so when towing heavy.

 

[VeryNoisyPoet]

Not a truck so not sure how useful this data will be, but my car has an oil to coolant heat exchanger in the rad, and I recently installed a digital oil temp and pressure gauge. Engine is turbocharged and has piston cooling jets which add a lot of heat to the oil. The non-turbo version does not have a factory oil cooler. Highway cruising will see coolant at 92C / 198F and the oil temp maybe 100C / 212F. In traffic the coolant temp comes up so coolant and oil will end up at around the same temp, oil maybe a few degrees warmer.

Climbing a grade with a full load on a hot day in 3rd gear at 3800 RPM, oil temps will climb to around 130C / 266F, while coolant temp will rise to maybe 105C / 221F. This should be taken with a grain of salt, as the oil cooler has a bypass thermostat. A few percent flow until oil is at 93C / 200F then gradual opening until full flow at 149C / 300F. I also have the electric fan modified to come on low when oil hits 110C / 230F and high when oil hits 125C / 257F. This keeps oil pressure higher under extreme conditions and provides better cooling for the whole system. Without the fan mods, temps would likely be higher, but apparently not so high that Volvo was overly concerned about it, even with 90s oil tech. The owners manual does warn not to tow a trailer in mountains at more than 4200 RPM to avoid overheating the oil.

As for reliability, the original oil cooler lines began to weep last summer at 174k miles and 19 years old, and the transmission cooler lines began weeping this spring at 183k miles. All since replaced so good for another couple decades

 

[meep]

Temps:

06 Tundra
Unloaded winter ~100F
Towing winter, OD off, 165F level and uphill

Unloaded summer ~135-150F
Towing Summer, 165F OD off
Towing summer, steep grades, up to 220F

notes. the larger trailer I usually maxed out at 60 mph but preferred 55. The smaller one I'll go 65. temps go up with OD on. I've learned the trans is fine because it's actively cooled. The axle, however, can get too hot if really pushing it, especially up steep grades. the tundra had a thermostatic valve that would bypass the cooler until needed.

Trailers used were ~4500 and 6,000 lbs loaded.

compare with chrysler FWD minivan:
if the A/C is on, winter or summer, it will eventually reach 165F
in the summer, 200-210F after 45 minutes

both measured with plumbed gauge.

 

[Piston_slap]

Originally Posted By: Snagglefoot
Any one have some sample temps?

Years ago I had a 64 Galaxie with a 400hp 390 and I added an oil cooler for the obvious benefits. I had a mechanical temp gauge with the sensor in the oil pan's sump. Steady speed driving showed the oil around 170 degrees. Pulling a grade on the interstate would allow you to watch it rise to perhaps 210, reacting almost immediately to the grade. Really spirited driving, such as having a 64 Impala for breakfast might run it up to 240.

This was with Kendall 40w racing oil in an 8 quart system.