Feeding a 911 for a while

The last few days here in the UK have been quite hot (well, we think it is hot!). I have noticed that my oil pressure is only 3.5 bar at 4000RPM
and 0.5 bar at idle. Should I be worried or is this quite normal. The oil temp needle is bang in the middle of the gauge and I am using a 10W-40 semi synthetic oil. Is it worth upgrading a 180HP SC with a proper oil cooler??

Tom F

My 180 hp SC behaves exactly the same way, and seems to be fine. It really is hot here - 101 Fahrenheit yesterday, and humid, too! I have the loop cooler, and it seems to work fine. Only if you have A/C or run the car on the track does an oil cooler upgrade become essential, IMHO.

Von Kiser

I would think 10W-40 is too thin of oil for the 911 engine...especially in the summer. I would suggest to upgrading to a minimum of 15W-50 or a 20W-50...never any thinner than that. 10W-40 is thin to start with, then when you add a hot day into the equation it is really thinning out...so your pressure is dropping.

my 1/50th of a dollar,
--Brian

911SOUK

My SC motor does the same thing. I'll be installing 2.5MM camshaft oil orifice (stock up to '91 is 6MM, too much oil), and when I get to it (a bigger job) I'll replace the oil relief spring.

I just learned of this and my research indicates the orifices are a good choice.

Steve Zitelli

My euro 76 with a proper rebuild and stock front oil cooler reads about 1 bar lower then it should when the temp reaches around 100 C which is the hottest it gets on 95 humid days going 90.I was wondering the same thing if this was okay.I also agree a 911 likes 20/50 when it gets hot.

Bryan Moore

The owner's manual for my '80 SC recommends 20-50 for warm weather. I cheat a bit with 15-50, but since it's Mobil 1, I figure it's probably okay.