Barn-find Porsche, Part II: And then things took a turn…

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porsche 911 rear 3/4 Brad Phillips

In my newly resurrected Porsche 911 Carrera, I was about to head off for the Smoky Mountain Tour through the Carolinas. This was going to be fun—we were partnering with the folks at Grassroots Motorsports and Classic Motorsports magazine, and the tour was going to take us all over the back roads for several days.

I’d driven the 911 locally as often as possible, hoping to shake loose any problems before I got too far from home—not just to save myself from any headaches but Ramsey Potts too, since I planned to toss my RM/Sotheby’s friend the keys as soon as I arrived in Greenville, South Carolina, for the start of the tour. Ramsey was going to use the car for the week while I co-drove a TR6 hot rod with Grassroots’ Tim Suddard. Hey, I wasn’t kidding when I said I wanted to share the 911 experience!

porsche 911 road trip route
Bing Maps

The drive to the start was about 550 miles, then I’d be putting about another 900 miles on the car. That would make a nice and even 2000 miles for the adventure—just about perfect to really get to know the car and see what shakes out.

The first big road trip in a new-to-me car is really exciting. I think figuring out what you need to take and how to organize it is very satisfying. The storage space in a 911 is actually very good for a long trip. Up front, the “trunk” can easily hold a well-stuffed garment bag, and the fact that everything stored stays at ambient temperature is a delight compared to my time in cars like my Ferrari 308, where your luggage soaks up engine heat and fumes for the length of your drive.

porsche 911 suit coat in frunk
Brad Phillips

The inside of the cabin is also a wonderful story. The rear seat backs fold down, giving you a spot for a big duffel bag and then some. On the floor behind the driver’s seat, I usually put a tool bag, a few quarts of oil, paper towels, Rain-X, and a fire extinguisher. Into the glove box goes my EZ-Pass, an old tape deck/AUX adapter so I can listen to my iPod if I want some music, a USB charging block to connect to the 12V socket in the dash, and my magnetic arm to suction cup to the windshield so I can run navigation from my phone. The final task is sitting in the car, get my driving position all settled, and look around to make sure I have good visibility and nothing I’ve packed is going to move around as I’m driving. OK, let’s do it.   

porsche 911 behind the wheel on bridge
Brad Phillips

Setting out towards Greenville meant crossing the Chesapeake Bay Bridge Tunnel through Virginia Beach, one of my favorite drives. Everything was working pretty well. Hey, even the cruise control worked. At about 65 mph, the oil pressure showed about 4 bar (60 pounds or so of pressure) and the oil temperature was reading in the normal range. Really the only thing not at 100 percent on the car was the smoky startup situation, and I figured I’d get a good bead on the oil consumption running through a few tanks of fuel to see if I had worn valve guides or some other situation going on. I’d forgotten what a fuel miser a stock 911 can be, and its 21-gallon tank gives it incredible cruising range. You can generally get 500 miles per tank, but I decided to stop for snacks and fill up at each half tank instead.

I was watching the oil consumption, and when I topped off the fuel I added a quart to keep it above the first mark on the dipstick. The gauge on the dash that reads the oil level is notoriously unreliable on these cars, and it wasn’t registering any activity, so a good reason to always pay attention to the dipstick. These cars tend to burn a little oil anyway, I thought—I wasn’t terribly worried about it yet.

I arrived in Greenville and handed the keys to Ramsey, whose turn at the wheel would include the famously twisty “Tail of the Dragon” highway. I was with Suddard in his TR6, and we were having a great time. Over the next few days, we visited the BMW High Performance Driving School, the BMWCCA Foundation Museum, took a factory tour at the BMW manufacturing plant, drove the great scenic roads through Caesars Head State Park and Smoky Mountain National Park, and ended up in Highlands, North Carolina, which would serve as a “home base” for a couple of days.

porsche 911 at BMW center
Brad Phillips

The tour included 20 or so cars and a super fun bunch of people. The 911 was getting all smiles from Ramsey, and putting some miles on the car seemed to ease up the smoky startups. We did have a funny moment that was related to the oil level, which fortunately didn’t cause any damage. I had been conservative in my oil additions thus far, keeping the level between the marks on the dipstick but at the lower end of it, being fearful of putting too much in and causing a different type of smoke show.

Ramsey and I topped the fuel in the morning and were adding a quart as usual. We both agreed to just go for it and see how much it would take to get to the top of the dipstick mark and see how much was really in it. Two quarts went in, then three. Four. Five. Five? Yes, we put five quarts of oil in it to bring it to the top of the dipstick, and hey, guess what? The gauge also popped up to the full mark at hot idle. How about that? Fortunately, the 911 has a dry sump system with a total capacity of about 13 quarts, so no damage done. I’ll keep the mark on the dipstick a little higher now without the fear of overfilling it.

porsche 911 gas guage
Brad Phillips

With the oil level situation sorted out, the car performed perfectly for the rest of the tour through the mountains, including some serious fun on the Tail of the Dragon and the obligatory stop for souvenirs. Following the final banquet, it was time to pack up and retake the helm of Zee German for the drive back home up the coast.

porsche 911 road trip bmw z4 ford gt
Brad Phillips

I was chomping at the bit to get back behind the wheel of my own car after seeing Ramsey having so much fun, and off I went back up the highway towards Maryland. All was well for the next 450 miles or so, then the car lost power and starting cutting out. I pulled to the side of the road—fortunately I had already crossed the Chesapeake Bay Bridge Tunnel system. The car was idling fine, so I eased out again. As soon as it pushed past 3000 rpm, it would start cutting out again until I dropped speed and rpm. This kind of breakup usually indicates a spark or fuel problem, and I was hoping this was going to be a fix that I could figure out. I kept it below three grand on the tach the rest of the way home, not a big deal with an overdrive fifth gear; I just had to accelerate like I was driving on ice in order to do it smoothly.

I have a pretty good library of Porsche technical manuals at home that I can consult, and I’m fortunate to have friends that know a good bit about Porsches, too. I called my buddy Keith at Martin’s German Service in Roanoke, Virginia, and told him what had been happening. There are several sensors that control spark, fuel, and mixture on these 3.2-liter engines, and it’s normal over time for them to build up a resistance and not operate correctly. I did some testing with an Ohmmeter and determined that one of them wasn’t reading properly, but you’re crazy to just replace one of them if you’re already in there.

porsche 911 engine
Brad Phillips

Getting to the flywheel sensors means jacking up the car and pulling the driver’s side wheel, and on my car that also meant cleaning a lot of muck off the area where I needed to work. Also required is the removal of the booster fan, but that’s just a few bolts. Upon inspection, the sensors were indeed the originals, so this seemed to be a good course of action.

Porsche wiring harness issues
Brad Phillips

Naturally, although one of the sensors came right out, the other was stuck tight in the housing. Fantastic. I was hoping to avoid pulling the bracket off the engine as there is an adjustment I didn’t want to disturb, but what the heck. It came off easier than I thought it would, and I did indeed have to use a press to get it out of the bracket. The hardest part of the job came after reinstalling the sensors—snaking the new wiring up through the back of the engine bay and reconnecting it. It would have been great if any of this had actually fixed my problem, but after buttoning up the car and taking it for a test drive, it ran exactly the same. Drat.

porsche 911 sensor location
Brad Phillips

Of course, the real problem was the third sensor, the one that reads off the cylinder head temperature and the one I didn’t buy. OK, here we go again. Jack up the car, order the part, remove the old sensor, replace the new sensor, button it up—and out the garage I went for another test drive. This time it felt different. Smooth power was back all the way to redline! I must have stayed out in the car for over an hour, really feeling great about how it was running.

porsche 911 sensor
Brad Phillips

Because I’m the poster boy for “Murphy’s Law,” my excitement was short lived. I got back home and turned the car off in the driveway. When I tried to restart it a few minutes later, it just cranked and wouldn’t start. What the?! Another quick internet search, a plea on Facebook, and a second call to Keith (who should probably change his phone number if he wants to get any sleep). This time, things were pointing to the DME relay, which controls the fuel pump and seems to be another weak link in these cars. Located beneath the driver’s seat, it didn’t require too much effort to pull it, and I was looking at yet another original part about to be replaced.

porsche 911 sensor
Brad Phillips

The 1987 date code told the story, as these are notorious ignition-failure points over time. Why did it decide to die at this particular moment? Were the “Car Gods” giving me a break by allowing everything to fail at once so I could have trouble-free motoring for years to come? I’m going to go with that for now.

Getting the Carrera back in action took three sensors and a relay, costing me no more than about $300 in parts and my time. I also changed the fuel filter (which had a 1990 date code) and air filter, along with the plug wires, cap, and rotor. Spark plugs are soon to follow. I have some epic road trips planned for 2019, so we’ll see what breaks next!

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