World Superbike Racer
Join Date: Nov 2012
Thanked 334 Times in 273 Posts
Feedback Score: 4 reviews
Here's the deal. You can't really test the oil cooler or water pump. There's a chance it could be the internal seal on the water pump letting oil into your coolant. But somehow your res got full enough to spill, which only happens if you get over pressure in your coolant lines from over heating or from something pumping into your coolant. This happens when you blow a head gasket. Not too common but still possible when you blow the internal seal in your water pump.
You can't really test the water pump, but you can test for a blown head gasket by doing a compression test which is very easy and cheap to do. It will also save you money from having to buy a new pump and cooler if that doesn't prove to be the problem.
If you get good compression in all your cylinders, move on to the water pump.
"I don't want to burden you with my problems... but I think I've outgrown my yacht."