Ask the Service Manager Answered Questions

1/29/2008

Q.

I have a 2008 F-350 Superduty with a 6.4L diesel engine. The truck sits idle about 3-5 hours a day. I curently have around 18,000 miles on it. My question is how often should I get the oil changed. I'm not sure if I should go by time intervals or mileage intervals or what. Chris Bay Village

A. For vehicles that operate stationary for extended periods of time (defined as periods of idle 10 min or longer) you should follow the severe duty maintenance cycle which is as follows: oil/filter changes every 5000 mi or 200 engine hours, fuel filters every other oil change. For reference 1 hour of idle time is equivalent to 25 miles. Now the secondary downside of extended idle is soot deposits. A diesel engine relies on heat for combustion. When a diesel idles it cools down and therefore is not as efficient at burning the fuel which can lead to what is called "coking". This is basically unburned fuel which accumulates mostly in the egr and turbo systems. To minimize this effect keep idle times as low as possible and use of proper engine oil is imperative along with fuel additives (Ford has 2 different types and both help). Lastly, (I can't finish without a plug for Valley Ford) we can provide all your maintenance and repair needs, we also have a Preferred customer program which provides for add'l savings. Hope to see in the dealership! Joe Bell Service Director