Loss of power/oil problems WD

Thanks in advance

I'm thinking you have another problem. That is that antifreeze is getting into the crankcase from the radiator. Lots of things can cause this - head gasket failure, cracked head, cracked block, failed seals at the bottom of the sleeves. Any of these can introduce the cups of fluid necessary to make a milk shake. And Anti-freeze is abrasive and very bad for the lubrication quality of the oil. You may be able to smell the milk shake and detect the smell of antifreeze. And you should see a loss of radiator fluid.

Rebuilding a WD is not so very expensive. I've seen complete rebuilding kits as low as $395. With gaskets, the cost would be less than $500. But you need to identify the cause of the milk shake and that may mean additional expense. I just am not satisfied that enough water can get into the block from the muffler unless it was that way for an extended time.