Noticed after the last oil change that the oil level in the engine is slowly raising. No change in the coolant level so I don't thing it is a leak but suspect that there may be a leaky injector? Had trouble with a f550 With a 6.7 it wore out the bottom end bearings. My question is what or where can I test the injectors, and can they be tested in the truck? Any other ideas would be appreciated. Normal driving conditions daily to work 30 min each way 154,000 miles.