Hey, Looking to buy 1999 Dodge 2500 Cummins. Owner reports block change in 2002 under warranty due to compression problems on 99 motor. Owner says he got 19-20 mpg on 99 block but has gotten 14-16mpg with 2002 block. Truck runs great, it does have odd vibration at idle, but that may be harmonics. Just wondering why the fuel mileage drop with 2002 block change. I need wisdom.
Thanks

 

there shouldnt be no drop in mileage, it would nt be the block that would cause a drop in mileage it would have to be something else...how many miles are on the new engine, it might not be quite broke in yet but ya never know

 

Truck has 101,000 miles but block just has 47000. I don't know if they reflased computer. Truck is completely stock.

 

it should be getting perty well broke in now

 

Could it be computer related? Would a shift kit in tranny cause less mpg? I am just trying to come up with causes that I could rule out.

 

compression problems eh ? like a cracked 53 block?

 

Hey, I appreciate the comment, but I am a newbie please explain. The owner did not specify what the compression problem was only that cummins replaced the block under warranty. I have seen the receipt for the work.
Thanks

 

The n umber 53 blocks that were used in the 98-~2002 were prone to cracking - not sure if that would affect compression or not. You can find a bunch of info here:

53 Block FAQ and Information


What kind of tranny this truck have? If the milage dropped, I would like at tranny issues - especially if its an Automatic.