Plans: drain coolant, remove broken flange, remove tandem pump, replace tandem pump/head seal, install new green temp sensor in flange, install replacement flange, replace coolant, change the engine oil and filter, swap the cabin air filter, and then go try out the OEM lumbar upgrade seat swap seats I finished swapping last weekend.
Coolant drain: did they have to hide it behind the side skirts without giving us an easy access opening?
Remove broken flange: apparently, that flange has been weeping coolant for months/years. The O-ring seal to the head was crusty corroded like it wasn't sealing properly for quite some time.
Remove tandem pump: Trying to be meticulous about not getting any dirt in the openings or the seal was fun. Wash the engine bay before you do this next time! Thank you to the guys who posted the torque specs in a thread. My MkIV Bentley doesn't cover PD engines.
Install new temp sensor: silicone grease on the O-ring and the sensor with it's O-ring just pops right in.
Install replacement flange: cleaned the head contact area as best I could with a razor blade. Used silicone grease on the new O-ring. Torqued bolts after coating them with antiseize. (because I've owned other VW heads where those M6x1 steel bolts have broken off).
Replace coolant: (Here's where the yesterday's plan falls apart.
) You know that fuel leak on the tandem pump, several of the coolant hoses connecting to the coolant flange below the tandem pump on the head were swelling and starting to split from exposure to #2 diesel. I cut several of the hoses back to good material, and ordered some non-OEM hoses to replace the upper radiator hose and the oil cooler hoses, as those seemed to be in the worst condition. While replacing the seal behind the tandem pump, more #2 diesel spills out onto those hoses. In the end, I simply cut my old drained coolant with more distilled water to replace what was lost when I tried (
unsuccessfully) to replace the black temp sensor with the new green one, without draining any coolant and taking all this stuff loose. After I determine whether the new seal fixes my tandem pump, or the tandem pump is still leaking, then I will either order a new tandem pump and do this all over again, plus replace hoses, or if the new tandem pump seal was all I needed, then I'll just drain the coolant and replace several hoses some day.
Engine oil change & cabin filter: never got to this part of the fun... There's always tomorrow.
...Northeastern Maine, nothing to bother you but Mosquitos and Moose...
Ha! I'm used to skeeters, had a collection of Asian Tiger Mosquitos in my driveway today. Need to fire up one of my Mosquito Magnets for a week or two and kill them off. This "dry season" (winter) in South Florida has been unusually warm and wet.