Do I Want an Oil Cooler or Transmission Cooler?
09-21-2009, 09:45 AM
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St. Jude Donor '13
Do I Want an Oil Cooler or Transmission Cooler?
My 2009 Coupe Z51 A6 has no engine oil cooler, and only the standard in-radiator transmission cooler.
Temperatures are typical, oil is about 210-220 cruising and trans is 160-200 depending on how much shifting it's doing.
This summer I was climbing a long mountain road, with a moderate amount of paddle shifting along the way. Air temp was <70 and I wasn't pushing the car at all. Oil got up to 255 and trans got to 220.
Those numbers are not damaging.
Based on info in the various manuals, I consider the "caution" range for oil to start at 275, redline 320. Transmission "caution" range starts at 230, redline 270.
But I could easily see getting much higher temperatures if I had been pushing the car or if outside air was warmer. Sometimes I do drive it hard. It would be embarassing to stop for a rest to avoid overtemping the car. So, I've considered installing the Z51 or Z06 oil cooler, and/or an extra tranny cooler (I don't think GM makes a tranny cooler, would need to go aftermarket or use a Z51 oil cooler for the tranny?).
It appears that the Z51/Z06 oil coolers do not have any effective thermostatic control, they cool the oil whether it needs cooling or not. Trans coolers are probably similar.
The problem is, our engine clearances were designed to run with Mobil 1 5W-30 at 210'-220'. Running the oil 20'-30' cooler would be like running 5W-40 oil, and doesn't sound like a great idea. Blackstone labs indicates that generally, thicker than specified oil usually reduces bottom-end wear but increases top-end wear.
Of course there are possible warranty issues, a non-GM tranny cooler being more likely to raise a flag.
Suggestions and comments?
Temperatures are typical, oil is about 210-220 cruising and trans is 160-200 depending on how much shifting it's doing.
This summer I was climbing a long mountain road, with a moderate amount of paddle shifting along the way. Air temp was <70 and I wasn't pushing the car at all. Oil got up to 255 and trans got to 220.
Those numbers are not damaging.
Based on info in the various manuals, I consider the "caution" range for oil to start at 275, redline 320. Transmission "caution" range starts at 230, redline 270.
But I could easily see getting much higher temperatures if I had been pushing the car or if outside air was warmer. Sometimes I do drive it hard. It would be embarassing to stop for a rest to avoid overtemping the car. So, I've considered installing the Z51 or Z06 oil cooler, and/or an extra tranny cooler (I don't think GM makes a tranny cooler, would need to go aftermarket or use a Z51 oil cooler for the tranny?).
It appears that the Z51/Z06 oil coolers do not have any effective thermostatic control, they cool the oil whether it needs cooling or not. Trans coolers are probably similar.
The problem is, our engine clearances were designed to run with Mobil 1 5W-30 at 210'-220'. Running the oil 20'-30' cooler would be like running 5W-40 oil, and doesn't sound like a great idea. Blackstone labs indicates that generally, thicker than specified oil usually reduces bottom-end wear but increases top-end wear.
Of course there are possible warranty issues, a non-GM tranny cooler being more likely to raise a flag.
Suggestions and comments?
Last edited by Gearhead Jim; 09-22-2009 at 10:50 PM.
09-22-2009, 10:52 PM
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St. Jude Donor '13
Nobody?
09-23-2009, 12:14 AM
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Unless your planning on hitting the track or pulling a 5th wheel, I think GM has your oil temps covered.
09-23-2009, 12:30 AM
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St. Jude Donor '09
My 2009 Coupe Z51 A6 has no engine oil cooler, and only the standard in-radiator transmission cooler.
Temperatures are typical, oil is about 210-220 cruising and trans is 160-200 depending on how much shifting it's doing.
This summer I was climbing a long mountain road, with a moderate amount of paddle shifting along the way. Air temp was <70 and I wasn't pushing the car at all. Oil got up to 255 and trans got to 220.
Those numbers are not damaging.
Based on info in the various manuals, I consider the "caution" range for oil to start at 275, redline 320. Transmission "caution" range starts at 230, redline 270.
But I could easily see getting much higher temperatures if I had been pushing the car or if outside air was warmer. Sometimes I do drive it hard. It would be embarassing to stop for a rest to avoid overtemping the car. So, I've considered installing the Z51 or Z06 oil cooler, and/or an extra tranny cooler (I don't think GM makes a tranny cooler, would need to go aftermarket or use a Z51 oil cooler for the tranny?).
It appears that the Z51/Z06 oil coolers do not have any effective thermostatic control, they cool the oil whether it needs cooling or not. Trans coolers are probably similar.
The problem is, our engine clearances were designed to run with Mobil 1 5W-30 at 210'-220'. Running the oil 20'-30' cooler would be like running 5W-40 oil, and doesn't sound like a great idea. Blackstone labs indicates that generally, thicker than specified oil usually reduces bottom-end wear but increases top-end wear.
Of course there are possible warranty issues, a non-GM tranny cooler being more likely to raise a flag.
Suggestions and comments?
Temperatures are typical, oil is about 210-220 cruising and trans is 160-200 depending on how much shifting it's doing.
This summer I was climbing a long mountain road, with a moderate amount of paddle shifting along the way. Air temp was <70 and I wasn't pushing the car at all. Oil got up to 255 and trans got to 220.
Those numbers are not damaging.
Based on info in the various manuals, I consider the "caution" range for oil to start at 275, redline 320. Transmission "caution" range starts at 230, redline 270.
But I could easily see getting much higher temperatures if I had been pushing the car or if outside air was warmer. Sometimes I do drive it hard. It would be embarassing to stop for a rest to avoid overtemping the car. So, I've considered installing the Z51 or Z06 oil cooler, and/or an extra tranny cooler (I don't think GM makes a tranny cooler, would need to go aftermarket or use a Z51 oil cooler for the tranny?).
It appears that the Z51/Z06 oil coolers do not have any effective thermostatic control, they cool the oil whether it needs cooling or not. Trans coolers are probably similar.
The problem is, our engine clearances were designed to run with Mobil 1 5W-30 at 210'-220'. Running the oil 20'-30' cooler would be like running 5W-40 oil, and doesn't sound like a great idea. Blackstone labs indicates that generally, thicker than specified oil usually reduces bottom-end wear but increases top-end wear.
Of course there are possible warranty issues, a non-GM tranny cooler being more likely to raise a flag.
Suggestions and comments?
http://forums.corvetteforum.com/c6-f...-products.html
I would suggest you post in the General Corvettes/Autocrossing and Roadracing forum for advice. Posting in this section gives you "General" answers. There are plenty with real-world experience in there that will give you real answers. I personally am considering an aftermarket radiator with EOC and TOC and possibly additional dedicated coolers on top of that.
San
09-23-2009, 12:30 AM
#5
Drifting
I has a Dewitt radiator with an oil cooler into it but I also installed an aftermarket engine oil cooler with a fan on it and a termerstat switch with 200 deg start and shuts off, it works very good and my car is a 2008.
I installed the cooler on the left side just above the brake ducts in the bumper and still has the oil going through the radiator for cooling.
I installed the cooler on the left side just above the brake ducts in the bumper and still has the oil going through the radiator for cooling.
09-23-2009, 06:11 AM
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My thoughts
Unless you are going to race the car you are probably fine as is. To ease your mind and added insurance you might want to do the oil cooler. I have both on my race cars and neither on my street car.
Jeffy'
Jeffy'
09-23-2009, 06:56 AM
#7
A good cooler will really extend the life of your transmission. And personally, I feel oil temps over 220 are dangerous. I've rebuilt a few engines, and those with stock cooling systems in warm climates usually had blued rod bearings. Those same type engines with mods, along with better cooling systems and an oil cooler looked fine. I'm running a Ron Davis radiator and a big oil cooler on my ProCharged C6, and they perform well together.
09-23-2009, 09:26 AM
#8
Melting Slicks
Heat is a huge enemy in the wrong doses. Seems that your concerns are good ones and I've considered some alternatives in my 09 A6 coupe as well.
All C6's should come standard with oil coolers and sufficient cooling to handle some spirited driving or tough driving conditions, including metropolitan stop and go.
The mod list for this winter just gets longer and longer............
FYI: You didn't mention how many miles on your car, but I've noticed recently that all of my running temperatures (highway/local, coolant,oil and tranny) have come down a few degrees since I've hit 5K. Break in might be a factor here also.
All C6's should come standard with oil coolers and sufficient cooling to handle some spirited driving or tough driving conditions, including metropolitan stop and go.
The mod list for this winter just gets longer and longer............
FYI: You didn't mention how many miles on your car, but I've noticed recently that all of my running temperatures (highway/local, coolant,oil and tranny) have come down a few degrees since I've hit 5K. Break in might be a factor here also.
09-23-2009, 09:54 AM
#9
Melting Slicks
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I have learned that the C6 Z51 Engine Oil cooler option does not flow 100% of the oil through the cooler.
it has a built in PSI valve and it only "shaves off" a small amount of oil that flowes through the engine and redirects it to be cooled by the internal radatior.
The factory AND dewitts EOC radatior cannot handel the 100% full volume of oil and maintain PSI.
it has a built in PSI valve and it only "shaves off" a small amount of oil that flowes through the engine and redirects it to be cooled by the internal radatior.
The factory AND dewitts EOC radatior cannot handel the 100% full volume of oil and maintain PSI.
09-23-2009, 10:29 AM
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Additional cooling may be beneficial but for 'normal' street driving I don't think it's necessary. I track my modified, non-Z51 C6 in Arizona where it's often hot. I may install additional cooling in the future but over the past 2+ years I've never had a heat related problem. Your concerns are well intentioned but unless you plan on seriously tracking your car I don't feel you need the additional coolers.
09-23-2009, 07:42 PM
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St. Jude Donor '13
Seriously, I'd like to keep this one a long time and that will mean a lot of miles under varying conditions. And I don't like to do a "cool-down lap" for highway driving.
If a cooler(s) will increase engine and transmission life for my sometimes vigorous highway driving, then I'd like to get that project out of the way and forget about it. If it won't be an improvement, or might cause different problems, then I'd like to drop the idea.
Right now, the replies have me leaning toward "Don't bother".
09-23-2009, 10:44 PM
#12
Former Vendor
I have learned that the C6 Z51 Engine Oil cooler option does not flow 100% of the oil through the cooler.
it has a built in PSI valve and it only "shaves off" a small amount of oil that flowes through the engine and redirects it to be cooled by the internal radatior.
The factory AND dewitts EOC radatior cannot handel the 100% full volume of oil and maintain PSI.
it has a built in PSI valve and it only "shaves off" a small amount of oil that flowes through the engine and redirects it to be cooled by the internal radatior.
The factory AND dewitts EOC radatior cannot handel the 100% full volume of oil and maintain PSI.
09-24-2009, 01:10 AM
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We put 6,000 miles on it during the first month, so I don't spend too much time sitting around worrying.
Seriously, I'd like to keep this one a long time and that will mean a lot of miles under varying conditions. And I don't like to do a "cool-down lap" for highway driving.
If a cooler(s) will increase engine and transmission life for my sometimes vigorous highway driving, then I'd like to get that project out of the way and forget about it. If it won't be an improvement, or might cause different problems, then I'd like to drop the idea.
Right now, the replies have me leaning toward "Don't bother".
Seriously, I'd like to keep this one a long time and that will mean a lot of miles under varying conditions. And I don't like to do a "cool-down lap" for highway driving.
If a cooler(s) will increase engine and transmission life for my sometimes vigorous highway driving, then I'd like to get that project out of the way and forget about it. If it won't be an improvement, or might cause different problems, then I'd like to drop the idea.
Right now, the replies have me leaning toward "Don't bother".
09-29-2009, 09:59 AM
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Melting Slicks
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10-08-2009, 10:43 AM
#15
How hard is it to install a Z51 oil cooler in a base 08? What parts have to be removed and reinstalled and/or replaced? SURELY there would not be any warrantee issues with this obvious upgrade(?)
10-08-2009, 01:08 PM
#16
I went with a Z06 oil cooler...much larger than the Z51. Found it ever so slightly used in the For Sale forum and purchased a new Z06 shroud to mount it in. The cooler is a direct bolt-on! I spent much more time installing the plastic Z06 shroud than I did bolting up the cooler!
10-08-2009, 08:52 PM
#17
I went with a Z06 oil cooler...much larger than the Z51. Found it ever so slightly used in the For Sale forum and purchased a new Z06 shroud to mount it in. The cooler is a direct bolt-on! I spent much more time installing the plastic Z06 shroud than I did bolting up the cooler!
10-08-2009, 08:59 PM
#18
I noticed an immediate 20-30 degree lowering of oil temps in all driving conditions after the oil cooler install. My F55 car previously had no oil cooler. The addition of the Z06 cooler added about 1 quart of oil capacity FWIW. I can't answer the auto transmission fluid question. Mine is an MN6 but it is running Mobil 1 synthetic ATF.
10-08-2009, 11:09 PM
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A good cooler will really extend the life of your transmission. And personally, I feel oil temps over 220 are dangerous. I've rebuilt a few engines, and those with stock cooling systems in warm climates usually had blued rod bearings. Those same type engines with mods, along with better cooling systems and an oil cooler looked fine. I'm running a Ron Davis radiator and a big oil cooler on my ProCharged C6, and they perform well together.
