WICruiser

I am staying with the original tensioner. I rebuild it when I did the belt previously and it has worked well so I decided to stay with it rather than changing to the Porken version.

ROG100

Nice to have choices 8>)

WICruiser

It has the fully equipped by Porsche version. I believe I have heard it referred to on this site as the Roger Box???

GregBBRD

I've looked at your pictures several times and something keeps catching my eye. Unless it is some sort of strange illusion, it appears that the aluminum directly surrounding the impeller and the impeller itself have pits from the green, cheap, incorrect coolant turning acidic and galvanic corrosion taking place.

WICruiser

I will look at the parts more carefully to see if what you are seeing are pits or residual coolant on the surfaces (pictures were taken shortly after disassembly).

Coolant was green, 50/50 mix made with distilled water.

Greg, what coolant do you recommend?

GregBBRD

Depending on how long the coolant will potentially be "contained" in the engine determines what coolant I use. Freshly rebuilt, engines that have had the heads refreshed, engines with factory water pumps and new factory hoses all get Porsche coolant. I figure these engines are likely to last at least ten years without opening the coolant system and the extra cost of the factory coolant will pay off, in the long run.

On engines that are bound to be opened up again or loose the coolant in a few years. I use Zerex GO 5. This includes any engine with any aftermarket water pump, any engine with aftermarket water hoses, or any engine that has the original head gaskets.

My logic is that there is no point in putting in more expensive coolant, which will last ten years. into something that is going to puke out the coolant or come back apart, in the next few years.

WICruiser

I looked at the pump more closely and there are no pits in the surface. There is a paint or ?? surface treatment on the non machined pump surfaces that is no longer in what I suspect are the high velocity flow areas.

Greg, thanks for the coolant information.