Help!! Im going through the whole oil cooler plugged up mess,question is how do I test to see if my headgaskets are good and has anyone done a good permanent fix. eg. egr sneakypipe or bulletproof egr etc. I Know egr fails after oil cooler does.My other concern is after I replace all this when I flush system(what is the best way and product) will all that sludge go back into my new oil cooler?