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1996 993 C4S Normal oil pressure, but warning light comes on - followup

Engine

Vehicle Information: Model: 993; Year: 1996; Body Type: Coupe; Total Mileage: 27,000;

Joel, follow up on the low oil pressure idiot light with the associated "lower" than normal analog oil pressure (little less than 1 bar) when hot, as requested. After some serious conversations questioning the wisdom of using 0-40 vs. 15-50 even in colder weather and implying that this could be the cause since the Porsche bulletin in their opinion refers to 0-40 oil recommendation for water cooled cars only, the independent shop I use reluctantly replaced the oil sending unit on the top of the motor. A real PITA. They did this as warranty as they replaced the same sender less than a year ago for a pesky oil leak. This in fact solved the problem even using 0-40 weight oil. When good and hot (9:00 oclock temperature), the analog gauge shows slightly above 1 bar. The idiot light has not fired while idling since the repair. Thought you might be interested in their take on the oil as, to their point, they have been using 15-50 in air cooled cars for years exclusively with very few if any engine issues related to oil in 993s. One guy I know pretty well who works there was formerly the top national Porsche certified/dealer mechanic awarded by PCNA years ago. He makes a pretty compelling argument about using 15-50 for all air cooled cars in all but the most extreme of cold weather where cars are left outside for weeks between starts. He points out that the core engine temp remains higher than ambient for quite a while even when it is really cold out. He also points out that the air cooled cars require thicker oil since tolerances are not as tight as those in the more controlled water cooled environment. Thanks for your feedback.

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