When the oil pressure starts to drop in a diesel engine, problems set in. First, the oil is not fully spread across the engine, which contributes to further problems. Shaft bearings start to wear as a result, including the camshaft. Piston rings start to wear, leading to excessive oil burning. Overall, a snowball effect takes place, leading to eventual engine destruction. When the oil pressure goes low, all additives claim to "fix" the problem instantly. Correctly fixing the problem, however, involves extensive diagnosis, including analysing the oil pump closely.
Low oil pressure in a diesel engine indicates something is seriously wrong. Trying to use additives to correct low oil pressure is like putting a band aid on a broken leg. Some additive makers have been known to make false claims of correcting engine problems. For example, the Federal Trade Commission in 2001 brought charges against Zmax oil additive for deceptive advertising.
The true causes of low oil pressure in a diesel engine are serious. First, check the oil level and type of oil you are using. The oil should be rated for diesel engines, and the proper viscosity must be used. The service department of the dealership that sells your make and model of vehicle can help you choose the right oil. If you are using the right oil, the next step is to suspect a faulty oil pump. Furthermore, Machinery Lubrication Magazine states that diesel fuel dilution causes low pressure at start-up. A qualified diesel technician can assist you in diagnosing and correcting the problem.
If the oil pressure is a little low, try some simple fixes. Using a thicker viscosity of oil might help. For example, suppose the manufacturer calls for using 5W-20 to 20W-30 for the oil weight. If you use 20W-30, this is slightly thicker. You are still staying within the recommended guidelines, but are using oil at the upper range of the recommended thickness scale. If you suspect fuel dilution, drain and change the oil and oil filter. This will get rid of the thinned out oil. You oil pump may be sensitive to changes like this, and perhaps the problem will self correct.
Steps To Take
Try the easy solutions first. If the oil pressure is just starting to go low, you may have to change the oil more often to overcome fuel dilution. Try to start your engine less frequently, as the experts state this leads to fuel dilution, particularly in cold weather. If the simple solutions do not resolve the problem, then professional expertise is needed to diagnose the root cause of the problem. Additives claim to correct problems, but these claims should be looked upon with scepticism.