MaxxForce DT Diesel Engine Injector Miss in a School Bus

An injector miss isn't too hard to detect since the engine code that showed up on the dash indicated a missing injector. This involved replacing the injector and a couple of seals on pressure sensors. The oil manifold is heavy and takes some work to move it on and off the top end of the engine. Once the injector is replaced and the hold down is torqued (22 ft lbs) the manifold sits on top supplying the high pressure oil from the HPOP (high pressure oil pump).

This high pressure system can get up to 4500 psi so if there are any weak spots and a leak develops the injectors stop firing properly. One test that really works well is to remove the main oil feed hose from the high pressure manifold and apply shop air to the manifold seeing if there are any leaks. If so there may be a failed seal someh where in the system.

If there are no leaks then there's a possibility of a bad IPR (injection pressure regulator) that screws into the HPOP controlling the pump output or the pump it self is not putting out pressure. Is this common? unfortunately yes we have changed out a HPOP and they are not cheap! $1700.00 while an injector runs around $500.00 which is Canadian funds. Yes it can a big owwie on the pocket book with these diesels. So I wanted to suggest something to anyone who runs MaxxForce engines.

They are bad for premature engine wear so the easiest solution is to shorten engine oil changes. We are now changing engine oil at 6000 mile (10,000 km). It's a cheap alternative compared to a premature inframe. Our fleet has had to rebuild 4 of our 2010 - 2011 DT engines due to no compression / high blow by situations. This really drives up the costs replacing pistons, liners, rings bearings, cylinder rebuild etc.

The labor on top of all this adds to the cost and down time. Another thing that would be worth going for is engine oil samples so engine conditions can be analyzed well before obvious problems occur. The results from engine oil testing covers everything from metals, fuel or coolant contamination. Well worth the cost! That's all I have to say about this subject. Leave a comments or questions below.

MaxxForce DT Diesel Engine

This video is on the big Bore Models in Highway Trucks and covers a large part on how the MaxxForce Engines are contructed.

The MaxxForce DT Diesel Engine is the newest edition of the original DT 466 and DT 466E diesel engines. Our fleet brought in five 2010 IC conventional school buses with this engine model. They are 230 HP with a 7.6 Liter (466 cu. in.) displacement.

They stuck with the wet sleeve cylinder design which is very popular with us Mechanics who do in-frames. If you've ever done an in-frame there is no comparison to an integral (DRY) cylinder diesel engine model. The dry sleeve design of course means pulling the entire engine out of the frame. This adds labor and parts expenses.

I did some research on these diesel engine models since it's always an advantage to know the details on our fleet engines. They have the roller cam followers which helps reduce wear and tear on the camshaft and valve train. A 4 valve per cylinder configuration helps with breathing and emission controls.

This video explains the EGR system in Maxxforce 2010 Engine Models.

Other features include:

• replaceable valve seats and guides
• top of engine access to fuel filter and fuel/water seperator
• top loading fuel strainer
• maintenance free closed crankcase ventilation system
• internal cylinder dosing eliminates downstream fuel injection equipment.
• On-board diagnostics system
• International's electro-hydraulic generation two (G2) electronic controls for optimizing fuel economy and delivery. 
• G2 fuel system allows diesel particulate regeneration without equipment dowstream.
• EVRT electronically controlled turbo creates improved engine torque curve and response and produces exhaust back pressure to better control EGR rate of flow and exhaust braking.

Jacobs exhaust brake (optional) up to 150 brake horse power. Works with the EVRT Turbo eliminating standard exhaust brake system.  The MaxxForce DT Diesel Engines in our fleet have been running great so far.