Tests and Treatments of Overhigh Diesel Oil Pressure
Posted: 2014-07-09 20:55:01 Hits: 1614
Excessive pressure of engine oil is a kind of fault that should be eliminated with judgment. Due to unexpected rise of engine oil pressure, it is liable to cause cracking of oil filter shell or oil sensor, and even burn up the bearing bush.
Common causes of high oil pressure are listed below: excessive viscosity of oil, blockings take place at the main oil way, cylinder and filter of the engine as well as improper adjustment of pressure limiting valve. Besides, too small gap of newly assembled engine bearing is also one of the reasons. The troubleshooting is to replace with suitable viscosity engine oil.
The elimination methods for increasing oil pressure result of blocked pressure-limiting valve or unsuitable adjustment is to do adjustment test for fuel injection pressure limiting valve. To remove the oil pressure sensor firstly. Then fit on a pressure gauge and start the engine to make the engine oil temperature reach 100 ℃. The engine oil pressure should reach 80kPa at idle and 380kPa at rated speed, otherwise the pressure limiting valve spring should be removed for elastic check. The spring force should be up to 123.5N and 197.5N respectively when the spring length is 30mm and 34mm.
When necessary, the spring force can be adjusted by the adjustable liner on the spring end. In winter, it’s a normal phenomenon to find that engine oil pressure stay on the high side after starting the engine, and then drop to normal value after preheating. If the oil pressure gauge indicating value is still more than normal, the pressure limiting valve should be adjusted to conform to the specified value. And then, if the value is still high after test-running, you need to check the brand of oil to see if the oil viscosity is too large. With suitable viscosity, it could be oil lubrication system road congestion that caused problems. Therefore, the clean diesel fuel should be applied for washing.
Starter can be used to drive the crankshaft 3 ~ 4 s while cleaning because of poor diesel fuel lubricity (Note: Do not start the engine). Once the engine fuel pressure rise suddenly when the vehicle is at work, please check the oil filter and bypass valve.
