Peter Wilson

Adelaide, Australia

Despite the lovely late summer weather down here in South Australia, there hasn’t been much Porsche driving. Any spare time has been spent preparing the car for our next road trip, to the Phillip Island Classic. This process started with my annual oil and filter change after about 5,000km of use through the year. After trying various brands and types of oil, I have settled on Penrite Racing 15. This local product is a 15W-50 full synthetic oil with a lot of zinc and boron anti-wear additives to protect the slidey parts of the valve train. It’s not cheap, but a 10-litre change costs only slightly more than a tankful of 98 octane. Then I performed my ritual of cutting open the oil filter and looking inside the paper element for any signs of metal particles. This was the cause of my engine rebuild a couple of years ago, when an aluminium oilway plug parted company with the crankshaft, causing low oil pressure and lots of shrapnel as it bounced around inside the crankcase. No problems this time, but there were some small carbon flakes, probably years old and slowly being removed from 40-year-old oil lines and coolers.

I made one change to my normal routine this time, which was to only refill the oil tank to the lowest dipstick line

(hot, level and idling) instead of halfway between the marks. I am trying to find out if oil travelling along the breather line from the oil tank into the air cleaner is due to tank pressurisation under boost (‘heavy breathing’) or just oil slopping down the breather under cornering. If the lower oil level fixes it, I know the answer was slopping. Otherwise I will add the OEM air/ oil separator which was fitted to latermodel 930s to fix the breathing issue.

Then I decided to do a backyard ‘steam clean’ of the engine undersides to remove the two years’ worth of road grime. I rigged up a tarpaulin nappy under the back of the car and used a kero gun to loosen up the grime. Any stubborn areas got a dose of aerosol degreaser before the whole lot was rinsed off with high-pressure water.

The only other work has been to fit an extra relay to the Daytime Running Light (DRL) system. I fitted a changeover (fivepin) relay to the ignition feed of the existing DRL relay. I used the Normally Closed contacts so that the DRLS are on unless the relay is energised by a signal from the headlamp circuit. The purpose is to disable the DRLS at night to avoid dazzling other motorists. I had to run a wire all the way from the light switch in the cabin to provide a signal regardless of low or high beam, which proved challenging as the 911 shell has very few bulkhead penetrations. I managed to find one and the upgraded system works just as intended, so I can now drive at night with a clear conscience.