Can anyone link or post instructions with/without pictures for a stock C6 Z06 oil cooler replacement? I have searched the forums and youtube for material on this subject and have come up empty. The little I did find involves upgrading the oil cooler. Or if someone has done this, share some lessons learned for efficiency purposes.

Thanks.

 

You have an early C6Z06 which means that you have an air-cooled engine oil cooler. While these work great on a track, they sort of suck in a street application, which is why GM finally changed to a coolant-to-engine oil unit in the later C6 years. One relatively easy fix is to change to a DeWitts radiator with an integrated transmission oil cooler and engine oil cooler. This solution essentially matches the OEM design, which will let the engine coolant bring the engine oil temperature up to design levels on a cold day. For cars that are tracked, I will say that the heat rejection capacity of the DeWitts radiator + EOC + TOC will probably not be sufficient, and your will need to seek other solutions to get rid of all that heat. I run a DeWitts radiator + EOC + TOC in my Z06/

 

Thanks

 

My stock 09 Z06 with the OEM air/oil cooler saw 280* oil temps on the track, more than I would have wanted, but not quite into the danger zone when running M1 0W-40 oil.

The DeWitts with IOC and ITC isa great setup for the street and worked "OK" for me on the track as I added 133 NA rwhp at the same time when the DeWitts was installed. Again higher than I wanted but OK at 285* oil temps and 245* water temps including running the LG vented hood to move more air thru the radiator.

 

Because the stock cooler works so well and not wanting it to take 30+ minutes to get to 180+ I did the Improved Racing oil thermostat kit. Now I have oil at 180+ in 10 minutes and it stays there. Here is a post I did on it. https://www.corvetteforum.com/forums...t-install.html

 

^^^ on the street.

 

Thanks for the info

 

because my z is mostly street w/ some strip duty i used the Z51 oil cooler.
50% smaller and mounts in same location, gets oil temp up driving around but still provides cooling.
those quick connect clips and fittings are a bitch, pick up some extra clips before you start

 

Do you track the car? If not - remove it and don’t worry about having a cooler.

 

No I don’t.

 

Honestly, I would not remove the oil cooler, even if the car is only street driven, as an oil cooler has more benefits than downsides!

i would either replace it with a stock Z06 cooler, slightly smaller Z51 oil cooler, or the oil thermostat kit......

Change your oil often and use a top quality true synthetic oil like Amsoil, Pennzoil Ultra, Sunoco European formula (commericall grade), etc...Most mass market USA oils are NOT true synthetics....they are highly refined Group III conventional oils which are more susceptible to lower oil temps.

My 10 Z06 does take a bit to warm up the oil to 180 degrees but my 2020 AMG GTC does, as well. I would never delete the oil cooler on either........

 

Agree…removed it on my last Z and my current Z. I don’t track it, so zero downside. Used to take forever to get to 160, never got much over 170, every once in a while I might hit 180. Now it warms up within a few miles, and I’ll routinely see 200-210. In the summer, highest I’ve seen so far is 215. It’s easy and cheap to remove, just need the block off plate and two bolts.

 

That IS the danger zone. Tracking 9/10 my 740 HP n/a Z06 sits at 185*F water and 195* oil with a dewitts, vented hood and all that. Sorry but you have a big problem somewhere.

 

When you say tracking, are you referring to 1/4 mile or road course, or high speed endurance run? If the latter two and your engine oil temperature is not exceeding 195 DegF, you are not trying hard enough. Press the right pedal to the floor and hold it there.

 

Owners who remove the engine oil cooler are stating that they are never willing to drive their Z06 cars hard enough to need to remove heat from the oil cooling system. This is not a reflection on our car design, it is a reflection on some of the owners of Z06 Corvettes.

 

If you do go to another cooler you might also look at beefing up the OEM cooler lines which at best are #8 (some bends are kind of tight). I did a #10 braided line. You need a 90-degree and a 120-degree swivel fitting to get good clearance on the engine block side. By using a swivel with the O-Ring fitting already combined with it this (compared to and AN10 male / AN10 female) saves over an inch of upward tube location which jams the line into the electrical and closer to Mr. Header.

 

That is a really nice replacement ^^^^^ of the oil cooler lines and connection to the filter housing which is very smart, especially for those that understand how and why an oil cooler is very beneficial on these types of motors, regardless of how they are driven............

 

I made a 2-piece oil cooler cover for my 2006 Z06 and put it up on Thingiverse.

The stock cooler on these cars is almost too efficient, especially street driving or cooler weather, and the oil can take forever to get some heat in it.

This cover goes over the factory oil cooler and blocks some airflow. It is two pieces, so it is easy to print and install.

I know it fits my 2006 Z06. It should also fit 2007 and probably 2008 cars with the same cooler setup, but I have not personally tested those. Later C6 cars may be different, so compare your setup before printing.

I’d print it in something that can handle heat/outdoor use, like PETG, ASA, ABS, etc. Definitely not PLA.

Thingiverse link:
https://www.thingiverse.com/thing:7372914

 

The below explains in detail why running 175-180 degree oil temps with my stock factory air oil cooler is perfectly fine on the street with my stock LS7 2010 Z06.

As I have mentioned, previously, I would not eliminate/block the factory oil cooler but if you insist would invest in a oil temp regulator that keeps the oil temp, max, 200 degrees on the street.

When you are running true high-tier synthetics, the math and physical behavior of the fluid change drastically. Along with the precise technical nuance of how those specific oils behave at 175°F–180°F:

1. Viscosity and Fluid Dynamics (The 0W Advantage)

The primary concern with low oil temperatures is typically excessive viscosity (the oil being too thick to flow properly into high-load zones, like the LS7's tight lifter buckets or valve guides).

• A true Group IV PAO (Polyalphaolefin) like Amsoil Signature Series, or a heavily refined Group III+ / IIIb Gas-to-Liquid (GTL) base stock like the Castrol Edge European Formula (German/Belgian imports), have exceptionally high Viscosity Indexes (VI).
  
• Because they use a 0W rating built on incredibly uniform molecular structures, their viscosity curve is much flatter than a standard fluid.
  
• At 175°F (approx. 80°C), a high-VI 0W−40 flows exceptionally well. Its kinematic viscosity at that temperature is only marginally thicker than it would be at 212°F. It is safely within the exact operational parameters required to protect the valvetrain, maintaining excellent flow velocity without creating the dangerous pressure spikes or heavy filter-bypass situations you'd get with a conventional oil.
  

2. Moisture and Volatility (The "Boil Off" Nuance)

The classic argument is that oil must hit 212°F to boil off water. However, physics dictates that water evaporates at any temperature; it just does so faster at higher heat.

• True synthetic base stocks have incredibly low Noack Volatility percentages. This means the oil itself doesn't burn off or vaporize easily, but it allows trapped moisture to release efficiently.
  
• At 175°F–180°F, as long as the engine is driven long enough to reach full thermal equilibrium (meaning it stays at that temperature for 20–30+ minutes rather than short 5-minute trips), moisture will steadily vaporize out of the crankcase via the PCV system. It doesn't require a violent boil at 212°F to clean the sump, provided the oil's additive package resists emulsification, which both Amsoil and Castrol Edge Euro do masterfully.
  

3. Modern Additive Chemistry Activation

While older generation ZDDP and anti-wear packages required massive thermal energy to activate and bond to metal surfaces, modern high-end synthetic formulations utilize highly reactive, advanced zinc variants and co-additives (like boron or molybdenum) that initiate surface passivation and protective barrier formation at much lower thermal thresholds—well below 175°F.

The Adjusted Verdict

If you are running an elite fluid—whether it's a true PAO/Ester Group IV or a high-tier European GTL formula—a stable 175°F–180°F oil temperature will not cause harm. The film strength remains ironclad, the fluid is fluid enough to prevent accelerated wear, and the chemistry is sophisticated enough to manage normal combustion bypass. The only real caveat left is ensuring the car gets regular, sustained highway mileage rather than short, intermittent heat cycles, allowing the PCV system to do its job pulling out moisture at that lower thermal threshold.

 

What results have you noticed with the cover? I tried wrapping mine with aluminum tape first and it did make a difference in how quickly it warmed up as well as how hot it would get, but not enough in my opinion. Two years now running with no cooler and still very happy with my results.