If you have access to a Bentley manual, the cooler removal is covered in detail. First, jack up the car and remove the rear belly pan. There is a small 5 or 6 MM plug on the bottom of the engine that was covered by the pan, this is the coolant drain plug; remove it with a container than can hold 5 gallons (yes, you read correctly), of liquid. Remove the coolant cap in the rear trunk to facilitate draining. When the coolant drain slows, pull off each of the large hoses just in front of the coolant plug, these will drain the radiators. When the coolant drain is complete, replace the drain plug with a new sealing ring (a few cents at the dealer) after putting a light coating of anti seize on the plug threads. Torque drain plug to 7-11 Lb Ft. Reattach coolant hoses. Replace belly pan. Couple of useful tricks:
1. As you are fully draining the system, this is an excellent time to replace the factory 185 degree thermostat with the LN Engineering 160 degree unit. We have had excellent results with this swap, lowering around town coolant temps by 15-18 degrees.
2. Get the “-03” version coolant cap and replace you current unit. For a few bucks, it prevents major headaches later.
You need to open the engine bay, pull the air intake tube from the air filter box to the throttle body, and the cooler is exposed and ready to remove. Couple of tricks:
1. When the cooler is unbolted, do not move it, but lift it in a level position and slide a plastic bag under it to catch any residual oil and coolant still inside (there is a lot of both retained inside the unit and it will get all over if it drains while you are pulling it).
2. Wipe down the sealing area and always use four new (two sizes) o-rings.
3. If you are a 2.5/2.7 base engine, do not use the cooler for that engine, get the “S” model (996-107-025-57, about $200 from a good dealer). The “S” unit is more than twice the size of the base factory unit and will give you much better heat transfer.
4. Replace the Allen head fasteners and torque to 7 Lb Ft.
5. Replace the factory spring hose clamp on top of the cooler with a quality screw type.
6. On some models (but not all) there will be a close proximity between the new cooler and a hose; if you have that, just use a small section of split hose as a “sacrificial” wear protector. Again, not all models need this.
7. While you are in there, this is a great time to replace the air filter…….
8. Consider doing your poly rib belt as well at this time if it is anywhere near due, for $24, it is cheap insurance.
Button everything back up; you often find the throttle body end of the air tube can be a ***** to reconnect, but it does go back on. Refill the cooling system using the factory coolant premixed 50/50 with distilled water (ONLY; again, for less than a buck a gallon, distilled water is cheap protection); again the Bentley has instructions for this if you do not have access to a vacuum fill system, but using the vacuum system makes the refill a 5 min. no-brainer, and even pretests the system for any potential leaks. Unfortunately, the Porsche OEM vacuum fill system sells for over $500; but the company that makes them for Porsche is in Canada and sells the same unit, but with adaptors to fit anything from a Porsche to a lawn tractor for less than $100; so it is a good “buddy group buy” if you don’t want to spring for one yourself, but they really are handy for anything with a cooling system……..