I doubt the engineers at VAG expected this to happen. And that's okay, right? We're human and this is no Radio Flyer wagon. The early Cayenne models that are equipped with V8 engines have an achilles heel: The plastic pipes that carry coolant located underneath the intake manifold are cracking, effectively spilling coolant to the external surfaces of the engine: right where you don't want it to be. This causes inconvenience, unforseen expense and grave disappointment because it's a Porsche Sports SUV and this kind of thing just shouldn't be happening! Here is a glimpse of this unfortunately common problem and what we do to solve it. Click on the photos to enlarge and read on......
We begin our process by prepping our workspace and covering the vehicle's front end. Next, a pressure test of the cooling system confirms the leak, dripping down the back side of the engine.
The covers in the engine compartment are removed for access, as are the air injection pumps, mounting brackets and "dog-bone" engine stabilizer.
The intake manifold , throttle body and intake pipe are removed here. Note the blue towels- they are placed into the intake ports to prevent debris from entering. Open ports tend to swallow dirt and hardware.
Here is a closeup of the components. The thermostat housing is removed and cleaned. The thermostat and bleeder hose are both items that have a lifespan. When we do this job, we prefer to replace these because they can become issues down the road.
The cooling pipes break upon removal. We pay special attention to removing any and all pieces, debris and build-up on the aluminum manifolds. This is crucial to long-term integrity of the cooling system, however, and a very tedious process.
The large diameter aluminum cooling pipe is installed with the new rubber coupler hose and new heavy duty hose clamps. We position the hose clamps this way to provide access without interfering with any other component.
The upper aluminum cooling pipes are installed along with the new thermostat, housing gasket and bleeder hose. The new pipes are o-ring slip fitted into the block and thermostat housing assemblies.
The intake manifold is then installed with new gaskets. All other components are assembled and installed. We vacuum fill, bleed and pressure test the cooling system to ensure our work is solid and leaks are licked. After we're happy with it, we take it out and do donuts in the parking lot:)