tt9714

Documentation on why a water pump with metal impeller can cause irreversible damage.

This is a subset of my ongoing thread: "What's my next move?"
https://rennlist.com/forums/boxster-and-boxster-s-986-forum/1126901-what-is-my-next-move-4.html

Photos below show comparisons of:

• LEFT: original block / genuine Porsche water pump (plastic impeller); 28K miles
• RIGHT: replacement block from engine swap / aftermarket water pump (metal impeller); mileage unknown

Besides the coolant gelling problem (green + orange = gel) you can see the damage to the block on the right.
I measured both original & replacement block and average difference is (0.31) mm between replacement & original.

Now I have to make a decision:

• Choice 1: take my chances with swap engine (risk from gelled coolant & risk from case damage)
• Choice 2: return engine to seller, absorb $450-500 return shipping fee, and look for another engine

LEFT: genuine Porsche; RIGHT: aftermarket with metal impeller AND gel

LEFT: genuine Porsche; RIGHT: aftermarket with metal impeller

LEFT: genuine Porsche; RIGHT: aftermarket with metal impeller

Brian in Tucson

Have you run this by the seller? That damage is not good. Might be okay with a proper water pump, but would you be satisfied?

How far away is the seller from the south bay?

AnthonyGS

Porschetech3

My .02 cents/ opinions.

The Porsche green/pink(orange) coolant is compatible/mixable and will not gel. Other formulas maybe, but Dexcool is known to be the most recognized offender.

I would be suspicious of an intermix of oil causing the gel/mayonnaise gel like substance, from either a previous or present intermix condition.

That engine should be carefully evaluated or returned. Surely I would expect the seller, if a business with a warranty, to pay for return.

If you are stuck with the engine, I would carefully evaluate for an intermix condition. Then after conclusion, look to the water pump efficiency issue.

If the block wear/score is smooth and not grooved and only 0.31mm deep, I would measure the gasket thickness. Use a 0.31mm THINNER gasket or sealer to restore the water pump efficiency back to factory specs. Note : carefully bolt the WP back on the block and rotate by hand to ensure no contact of the impeller to block. Hope this helps..

Charles Navarro

I'd return it. I also don't like that whoever was working on the used engine copper-coated the water pump gasket. Makes me think they re-used it and question what else was done to that engine. The returned shipping cost might be the lesser evil.

Brian in Tucson

I agree.