Your looking for 350psi on a new engine 300psi on a broke in engine. You are allowed up to a 100psi variance between cylinders.

 

well i tried the tool on the rest of the cylanders but now the damn guage looses the pressure as soon as i stop cranking its pissing me off, so needless to say the rings on the 3rd cylander aint broke seated yet and the rest are?

 

i got the tester working again today and they are all about the same roughly 350psi per i tried the leakdown test and cant figure it out. tried to get the piston at tdc, wasnt workin out to well for mei think i will have to take the damn thing into the shop to have them look at it

 

I may be crazy but at 2400 miles your rings haven't even begun to seat, I would give it some time and see what it does.

 

ya know ive had multiple people tell me that they arent seated yet and ive had multiple people tell me that they seated 1000 miles ago its beyond me i would hate to keep driving the hell out of it and it be abroken ring or something stupid like that

 

well i had about 12 cummins guys look at the truck today and they all said the same thing. lack of compression in that single cylander. so tomarrow night im yanking the head and the 3rd piston

 

i yanked the piston last night and sure enough it didnt seat were there rest of them are the cylander is smooth as can be and the piston rings have no wear at all

 

Please keep us updated.

 

the rings didnt seat at all so ill post when i get it back together

 

well i got the piston in tonight and the oil pan on, i can offically say in-frame rebuilds are not for me trying to reach my hand up inside to pull the rod over the crank was a pain in the ***. had to use 3 comalongs to get the engine straight for it to fit in the mounting brackets in the frame rail that was fun, the worst was trying to get the pan and gasket on 2 damn hours just for the damn pan, the jackasses sent me the wrong head gasket so no i have to order one from cummins hopefully it will be here friday