On june 18th of this year I had my motorhome checked for low power at MHC. The mechanic John Tymon advised he would have to run a computer scan to see what may be causing the problem....he advised that the engine over heated 3 times and suggested the radiator needed to be blown out and coolant needed to be changed. This was done along with another statement that the air filter was cracked and needed to be changed. not done due to no parts available, We then road tested and it did a little better but not much. I made it back to new orleans and had it serviced by S&H diesel service and they immediately advised that my problem had nothing to do with the coolant or the air filter...….THE PROBLEM WAS A CRACKED EXHAUST MANIFOLD.....thanks MHC for taking my 734.48 and not finding the problem. TOTAL LABOR 570.00 for doing nothing....check and recheck on this dealer in Ardmore before you allow them to service your vehicle...