Testing Oil cooler?
 

Ok it was easy to remove but how the heck do you test it? Either these are impeller chunks or spark plug tube chunks:

http://986forum.com/forums/uploads01...1444408174.jpg

The heat exchanger (not a cooler to be pedantic) is exactly where the broken black plastic impeller pieces lodge. Not good for coolant flow.
If you read the water pump impeller threads you will notice a couple of things:
1. Helpfully ,Raby mentions the circulation of broken impeller vanes, few respond.
2. Preventative maintenance -replacement every 50/60K gets groans of derision.
3. If you suggest using a metal impeller+ routine replacement howls of derision.
4. The heat exchanger is not the only place the small plastic pieces accumulate...you find this out when you totally dismantle and clean the engine for rebuilding.

Somehow you need to remove all the broken pieces left by the mechanic when he slapped in a new w/p. Do a coolant flow test ?
Good luck and tell us what you find?

Easy, if the debris is in an oil passage, it is spark plug tube bits or chain tensioner wear pads; if it is in the coolant passages, it is from the water pump.

Pulling and holding a sustained vacuum for 1 hour on both the coolant and oil sides is the best test.

Wondering what you use to do this? I've been chasing a small leak that replacing the O rings didn't fix.

To vacuum test it, an hand held MityVac vacuum pump system and some rubber plugs gets the job done:

https://m.media-amazon.com/images/I/...AC_SL1500_.jpg

Thanks for the quick reply. I have one of those, just have to search the shop to find the correct sized rubber plugs, etc.

My leak was the coolant passage cover which is directly below the oil cooler.

Glad to hear you got it covered! What's next? Self-repair? Indy?

I’m a retired Indy, A new updated gasket solved the leak.