The CAT D398 is a 12-cylinder engine in V-shape, with 6 cylinders at each bank. It is among those Caterpillar products that are known for durability and resilience.
These are the common problems of the CAT D398.
1. Pre-lube Pump Failure: This pump is there to lubricate the engine components before the engine starts running. The pump helps to reduce wear on engine components.
The pre-lube system usually fails, which can be known by the dashboard light indicating oil system failure.
2.Burning Oil- This is one of the common complaints about the engine. When oil is burning, you will notice blue smoke coming out of the exhaust tailpipe. When this happens, you need to add engine oil each time you want to run the engine.
Oil burning in the CAT D398 can be very costly. Oil burning could be a result of three things;
- a. Worn turbo is one of the reasons why you may be having oil burning. If the turbo is worn, it allows the oil to escape to the exhaust, causing it to get burned.
- b. From the valve stem: The oil that comes to lubricate the rocker’s arm can still go down to the combustion chamber if the valve accessories are bad. If such a thing happen, then there the oil will burn.
- c. Bad piston rings, pistons, and or liners are another reason that can cause oil to burn. If any of the mentioned components have wear, it will allow oil to escape from the cylinder wall to the combustion chamber.
3.Crank Problems: The third common problem found in the CAT D398 is that the crank does not start even with ether. Ether is referred to as a starting fluid. If the starter fluid cannot start the engine, it means two things: low compression or a blocked air system.
Sometimes, due to an emergency shutdown, the air passage may have closed, which prevents the engine from starting. The engine needs air to burn the fuel to run; in the absence of no air, the engine will fail to run no matter the amount of ether you use.
Having low compression is another thing that could prevent your engine from starting even with ether. Ether serves as fuel, but without compression, the engine will not run.
Low Compression is a result of a faulty cylinder head and worn piston rings. These are the two common things that could cause low compression in the D398.
But if, after applying ether, the engine runs and stops immediately, then you should check the fuel line.
Steam is coming from the breather and dipstick. When you have steam coming from the dipstick, it means there is a problem with the engine.
A leak-down pressure could be why you are having such a problem. Leak-down pressure results from bad piston rings, which allow the compression to leak downward and build pressure in the crankcase.
A clearance between the crankshaft and the bearings can also be the reason for this. This clearance causes bubbles with built pressure in the crankcase and later comes out in the form of vapor or steam.
Check out in this article some general problems and solutions for most diesel engines HERE.
Purchase parts for your CAT D398 at ProDieselPart.
