International DT466 Diesel Engine In-Frame
One disadvantage to diesel engines with wet liners (meaning that they are removable from the engine block) is the o-ring seals that separate the coolant from the crankcase DO fail eventually. That is what happened to one of our buses while it was out on a run. The tell tale sign is the engine overheats and there is a significant loss of coolant.
One of the big advantages of the DT466 engine is the easy steps to rebuild the engine which is an in-frame. In-frame is exactly what it says….the block does not have to be removed and the head, pistons and cylinder liners can be replaced while the block is still in the frame.
This has always been a bonus with DT466 models because of the low cost and minimum labour hours it takes to carry out the job. The cylinder head was inspected after removal and sent down to the machine shop we deal with so they could check for cracks and wear tolerances. The in-frame kit comes with new cylinder liners, pistons, gaskets and seals.
In this case the seals just let go and allowed a large amount of coolant to leak into the crankcase. There are cases where the seals give out gradually and can be detected by taking oil samples. This way the repair can be carried out sooner without any major damage or inconvenience incurred out in the field.
Cylinder Liners Updated Seals
It’s a good idea to keep updated with TSBs (technical service bulletins). We found out during this job that new liners come with one seal only instead of the typical 2 o-ring style. The bulletin advises using vegetable oil to lubricate the liner seal before the installation (We used ‘Lubriplate’ grease) It’s a great substitute. Another important note is once the cylinder liners are installed make sure they are secured with liner hold downs.
The block clean up also involves a visual inspection checking for cracks and pitting in the casting and the top deck. A straight edge can be placed on top of the block to check for any uneven surfaces. There is a .001 to .003 inch allowance for wear. It’s typical not to find too much wrong with the DT especially since this engine only had around 100,000 KM (60,000 miles) on it.
Checking Related Parts
Since the pistons and liners are going to be renewed it’s a good time to get the turbocharger checked out and the injectors tested or replaced with remanufactured ones. Anything else that’s related is important to insure a good start up after the repair. Depending what has to be done to the cylinder head and the time it takes to clean parts there is more than enough time to do a proper job. Get the factory torque specs and reassembly information as well.
There are lots of resources available from the dealer in the form of a CD that will guide you on the right way to put this engine together. I always say to new guys in the trade give it all the effort you got with the simple tasks but take care when it comes to reassembly and adjustments Do it right once and you will never have to worry about a come back.