CM 871

[Aussie Steve]

Hi Fellas,
I have a CM871 in a Kenworth T909 that pulls road trains in Queensland Australia.
It has a number of issues that I'm seeking help with please.
The current engine is a Cummins Recon set at 600/2050, pulling three trailers on average grossing 120 - 130 metric tonnes, [265 - 285 000 lbs] in high ambient air temps 40-45 C,
[110 F]. Its is running a double overdrive 18 speed with 4.89 diff ratios trying to maintain road speeds around 90 klm/hr [55 mph] average around 75 klm/hr. Engine at 1650 rpm at 90 klm/hr. The truck also does its fair share of slow bush work where road speeds average 45 klm.
This engine has 2200hrs and 95 000klm on it, average speed 43klm/hr
About 30 000klm into its life the problems started with high water and oil temps, more so the oil temps [stop eng light]. High soot levels in the oil and engine vibration when pulling hard, the vibration below 1500 rpm is what I would call extreme.
The oil cooler has the correct element fitted, oil thermostat has been changed to 215 F unit, water thermostat is a 160 F units. These have been changed several times [ there were some issues with faulty units]
There are no issues with radiators, water pumps, charge air coolers, Horton fans etc.
The engine was demandated at 1350 hrs and 56 000klm. We performed this on a dyno and basicly put a @m*m^2 version in it, [I'm waiting for my copy of insight to arrive to confirm this].
Horsepower output is the same as before slightly more torque. Dropped 4 psi boost pressure out of engine, it has two plates installed, one at the join at the back of the block and another where the mixer tube is.
It experienced run on issues at 1750 hrs and passed the injector leak of test.
At 2000 hrs the manifold was slobbering raw fuel, we removed the exhaust manifold and found 3 & 5 injectors leaking. they were replaced.
Currently the truck is back at the dealer with a slobbering manifold, [it was removed Friday],
it looks like it has done No 6 injector, the exhaust port is wet but the rear most valve is that clean it looks like brand new. They want to pull the head and I suspect it has washed the liners in at No 6 and probably 3 & 5 as well. It passed a blowby test but the engine has increased blowby in the last several weeks and you can smell the oil vapour.
I have an extensive maintenance history on the engine and I am fairly particular with the the maintenance. Also have an SOS history from new.
I am an ex Caterpillar fitter but this is my first Cummins so I'm flying a bit blind with this engine.
Sorry for the long winded post but there's a fair bit wrong with this engine and the downtime is brutal.
Any help or advise would be appreciated
Thanks