Even bearing the prestigious J. D. Power and Associates award for highest ranked nameplate for its Initial Quality Study (IAS) of automobile brands, Porsche still has occasional problems. One area that must be properly monitored and maintained to assure the integrity of your vehicle is the oil pressure. While the illuminated ‘OIL’ warning light is a clear indication of trouble, if that same light is flickering, diagnosis is complicated. Furthermore, flow problems could be indicated if the valves are ‘tapping’. Whether the issue is merely an annoyance or an indication of impending doom, any issues with oil pressure or flow must be rectified immediately either by you or by Everett Porsche Service & Repair.
Whether you have a minor adjustment or a major repair ahead of you can be determined by following the amended (“Troubleshooting Low Oil Pressure”, Underhood Service, 10/97):
When experiencing a low oil pressure condition, the best, most logical first step is to check the oil level with the dipstick (if applicable). Note that some Porsche models have no dipstick, just an oil level indicator just under the tachometer on the dashboard. Locate and remove the oil dipstick, wipe oil off with a clean rag and re-insert the dipstick; remove one again and check the oil level indicated. Adjust your car’s oil level accordingly. Be advised that all cars do eventually experience low oil pressure due to normal wear and tear, but as the oil system is a closed one, if there is a drastic decrease, it could indicate a leak. Any low oil pressure situations must be investigated to determine cause.
SEALS & GASKETS
If inspection indicates that your engine is leaking oil, change the gaskets and seals. Worn valve guides and seals can cause your engine to burn oil. Additionally, the rings and cylinders could need replacement as well. Everett Porsche Service & Repair can perform a wet compression test and a leak-down test to determine which component is causing the problem. Replacement of worn parts is best completed by a certified technician.
A car that is burning or leaking oil must be diagnosed and rectified immediately! Ignoring a consistently low oil pressure can eventually lead to catastrophic engine damage.
OIL CONDITION & VISCOSITY
It is essential that you determine the recommended viscosity for your engine. Higher viscosity oils like 20W-50, straight 30W or 40W are appropriate in warm-weather conditions, maintaining a good oil pressure. The heavier viscosities can cause problems in colder climates.
Lighter viscosity oils, like 5W-20 or straight 30W are ideal for cold weather starting and lubrication. The lower viscosities are too thin for hot weather driving. Many automobile and OE manufacturers recommend 5W-30 for year-round driving, both hot and cold.
If the oil level is good, and the viscosity is appropriate, but the pressure is still low, check the oil filter. It is possible that the filter is in need of change. Note that every time the oil is changed, it is good practice to change the oil filter as well. Change the filter and test drive your car to see if the problem is resolved.
Should the pressure still be low, the problem could be a clogged oil pump pickup screen. By dropping the oil pan, you can access the oil pump assembly. Visually inspect the pickup screen and clean/replace as indicated. Determine that the pickup tube is properly attached to the pump, with no leakage. This is a great time to inspect the oil pump as well for clearances and operation. A damaged or worn oil pump must be replaced.
If the oil pump appears to be alright, check the main bearing (closest to the pump) and rod clearance. This clearance has the greatest impact on oil pressure. Worn bearings must be replaced.
PRESSURE SENDING UNIT
A common problem with regards to improper oil pressure/level indicators is the pressure sending unit. Disconnect the unit and if the warning light is still illuminated, you have determined a probable short to ground within the lamp circuitry. The only accurate way to determine if the sending unit is faulty is with a pressure gage.
There are other diagnostic checks that can be performed: camshaft end play; pulling valve cover; removing intake manifold to check the cam bearings and lifters.