: Thermostat on oil cooler?

07-06-09, 11:54 PM
Been trying to figure this out but with no luck-- does the V2 have some sort of thermostat on the oil cooling circuit, or does it use engine temp somehow to turn on the cooler?

Without an oil temp gauge, I'm wondering how long the car really takes to warm up and whether I can trust the coolant temp gauge. My C6 Z06 has a gigantic oil cooler and no thermostat on the cooler, so it takes forever to get temp in the oil in cool weather--- the coolant gauge is very deceiving.

I'm guessing the V2 is more sophisticated, but I'm pretty particular about waiting until the motor is warm before pushing it. Any insights? Thanks.


07-07-09, 11:38 AM
I think it is just a sensor in the pan on the side of it..

07-07-09, 05:22 PM
I looked at all the sections in the factory service manual concerning the oil cooler and there was no mention of a thermostat for the oil cooler. I don't believe that there is one on the 2009 CTS-V oil cooler.

07-08-09, 12:56 PM
Thanks much for the replies. I tried tracing the lines from the pan mounted cooler to the grill to see if I could understand the system, but got lost in all the covers. Does the service manual show a dedicated pump for the coolant for the oil cooler circuit? If so, all is good since it is likely that the pump is cycled based on temp. If no pump, then I wonder how that oil coolant circuit works. Interestingly, the LSA, the LS9 and the LS3 in the Camaro SS appear to all run the same oil cooler setup (although I cannot find detailed info on any of them...)

07-09-09, 11:37 AM
There is no "coolant" supply for the oil cooler. The oil cooler uses air to cool the oil. The oil cooler is in the oil supply path and oil passes through the cooler as a result of oil circulation by the oil pump. The sensor mentioned by wait4me reads the oil level (a warning appears in the DIC if the oil level drops below the sensor) and has nothing to do with oil temperature.

07-09-09, 10:41 PM
tedcmiller, thanks for your patience with me on this. I really don't understand this system :hmm:. I thought this pan mounted cooler was a coolant-to-oil exchanger based on appearance, and here is something from the Camaro boys about the LS3 that also supported that assumption:

"In addition, the Camaro LS3 has an engine oil cooler because, according to ACE Ron Meegan, "...of the (vehicle) weight and the (reduced) air flow around the engine in this package, some of the more aggressive driving modes required us to use a cooler to meet our oil temperature requirements." The Camaro oil cooler is the same type of oil-to-coolant heat exchanger used by the supercharged LSA in the Cadillac CTS-V and it is mounted in a similar location, on the left side of the oil pan."

This is from http://www.camarohomepage.com/ls3/


I'll get it up on the lift this weekend and try to make sense of it. Thanks again.

07-09-09, 10:53 PM
I have looked closely at the factory service manual and what it has to say about the oil cooler. There is no mention of any coolant supply to the oil cooler on the LSA engine in the 2009 CTS-V. In fact, it clearly states that the oil flowing through the oil pan mounted oil cooler is air cooled. The picture of the Camero oil cooler shows no fins for air to flow over and probably does use the coolant supply to remove heat. The CTS-V cooler is not enclosed like the one in the picture and allows the passage of air.

07-10-09, 07:36 AM
Hmmm. That is weird. You can see the cooler on the pan in this image of the LSA from GM Powertrain (this is the 2010, but the 2009 is the same image) and it looks just like the exchanger on the Camaro. I'll see if I can sort it out this weekend. Thanks.


07-10-09, 11:24 AM
The 2010 CTS-V might have a coolant cooled oil cooler, but the factory service manual for the 2009 CTS/CTS-V does not show this. It does not mention removing a cover on the oil cooler and, as I said, specifically states that the oil cooler uses air cooling in the description of the oil system.

07-10-09, 11:54 AM
I don't doubt you or what the manual says, and I appreciate you taking the time to help figure this out. I'm just going off what is published by GM Powertrain. The 2009 LSA engine image is identical to what I posted above, and you can see the cooler in the lower center of the very cool exploded image below. I'll take it apart this weekend and figure out what is really on the car.


07-11-09, 08:42 PM
OK. I stand corrected. There is apparently a coolant supply to the oil cooler. I finally found the references to this in the installation and removal instructions for the oil cooler (connecting and disconnecting coolant supply hoses). The statement regarding air cooling applies to cooling the coolant. There is no indication as to which engines these removal and installation instructions apply, which usually means that they apply to all CTS/CTS-V engines.