What all do they do... adjust the valves and inspect everything?

 

Pull the heads, adjust the valves, check the jake and all the moving components in the upper end.

 

Well, the friend of mine, has ISX, at a bit over 400 grand, never run it. I mean overhead... :roll:
One suggestion, if you did experience fuel mileage drop after the last one.
Go to a different people for that service. Should be quiet the opposite, if it was done properly!

 

I get all my work done at that shop, because I trust them. I may take it to the local Cummins shop, though. Depends how much they charge.

 

I think it depends on who does the overhead. just because you brought it to a k.w. dealer or any other shop, does not mean much. one day they might have a a person doing the overhead that was trained to do it a specific way & another time at the same place you may get someone else who was trained to do it slightly different.


I had mine done 4 months ago & after driving my truck for 10 years & having the overhead done every 100,000 miles this last time done at freightliner in decatur al, my truck has more power then it did when I first bought the truck. it does blow out a lil more black smoke from the stack, but the m.p.g. is better & the power was increased by a noticable difference. srange to me to have a truck with over 1.1 mil miles perform better than when it had 400,000 miles.


but that is the case with mine. now I am afraid when the time comes for my overhead that if i take it in it will not perform as it is now.

 

I have a C16 600 ( turned up a little bit with PB power) and have it done every 100,000 miles. Even with the PB power I notice the difference in power but no drop in MPH.

 

I thought cummins factory recommendation was 500,000 miles? I remember reading that on their site, maybe that's the new ones.

Anyways, solo is absolutely right, if you noticed a loss, something wasn't done right.

There is more to the valve job then simply fuel mileage. Too tight and the valves hang open too long. This is especially bad for the exhaust valve, it can burn out. Too loose and the valve doesn't open enough, and it's hard on the valvetrain.

 

Actually Allan, I think you're right. I think that's why I was curious in the first place that the KW shop was saying I should get it done every 100,000 or so. I'd go look in my manual...but the truck's in the shop :roll: