Headlights - H4 100 Watt

I had the same worry as I went to 100 watt high beams and looked at the itty bitty switch contacts and as far as I recall all of the current goes through the switch.....not a good deal in my mind. I added relays to both high and low beams, Porsche sells the socket for the little round black relays separately and it is not a big deal to wire them in.

Basically all you do is use the existing circuit to activate the relay and then run power from an unused fuse or other circuit to your lights.

Takes about 2 hours with brain active, a whole day with a brain in need of reboot (guess which path I took!!)

Dennis Kalma    kalmad@cadvision.com
'75 911S with Kremer 3.2

PIAA (and others, probably) make a relay harness that really IS an easy plug-in... You simply unplug your existing harness from the bulb, plug it into the PIAA harness, then plug the PIAA harness's connector into your new bulb.

The only additional wiring that's necessary is a ground wire (to any convenient chassis screw) and a wire straight to the battery (through a fuse provided by PIAA).

PIAA's number is 800 321-1191.


=== Andrew Warren - fastfwd@ix.netcom.com


Hood Release - Won’t Open

>As of about two weeks ago the release (pull-handle) for the rear hood (trunk?) >stopped working.  I can still pull the handle out, but it doesn't open the trunk.  >Anybody know of a trick to get the engine lid open?

You need one more person to help you.When one is pulling the handle, one should open the lid.

--Clemson Chan    ycc@inpart.com
'78 930 (had the same problem fixed)


I believe there is an access hole for a wire to pass through and catch the latch. It was shown in my manual for my 69 but in my manual for my 81 is only says it will open if the cable breaks. The bad news is either way it ain't easy. Hopefully the two person suggestion will work.

Todd Meisner


Hex Bolt - Stripped

After the hex head is stripped, I usually "Vise-Grip" them out.  Some penetrating oil sprayed at the base of the CV joint, and left overnight, can help as well.  BTW, the replacement bolts for those are widely available at hardware stores which carry metric selections.

Chip Evaul


Hood - Won’t shut

> The engine lid on my 911 will not latch shut. 

Undo the cable and take the latch out totally.  Get a big can of WD40 with the little straw on it and spray the insides liberally.  A LOT of black gunk and dirty WD40 will come out the other side.  If you catch it all in a little tin you can then soak the latch in the runoff for about 10 minutes.  After soaking, rinse with WD40 again and dry with a shop rag.  You might also take something small and poke around in it to get all the gunk out.  Get some all purpose grease and spread liberally inside of the latch.  Put the latch back in the car.

Adjusting the wire on mine took some trys.  It can not be loose, but if you tighten it too far your lid will not be held in place.  There is a happy medium.  I found that if you start when the wire just begins to pull back the one moving part in the latch you will not be far from the correct point.

Also, if the post on the engine lid is too short then it will not stay closed.  You should be able to adjust this with a big flat head screwdriver.  Mine was too long and made it look like the engine lid was open sometimes.

All of this pertains to my '82 SC, but I think it should do for your 73 as well.  Some things never change.  Err, I just stopped to look in my stoddards catalog and they list the latch and post as being 74-89. Well, try it and see what happens. 

Michael Rothenberg         mrothenberg@pria.com
'82 911 SC, Euro needing lots of TLC

After lubricating both the latch receiver mechanism in the body and the stub sticking down from the rear deck lid, try shortening the stub.  It has a flat blade screwdriver slot at the bottom which screws it in and out after loosening the locknut.  Surprisingly, shortening it usually allows it to lock, while lengthening it makes it keep springing open. Make small adjustments so it doesn't lock and refuse to unlatch.  You should be able to get it to latch with just a slight push shut.

Peter Cowper     pcowper@webtv.net

The engine lid latch is designed to "fail open", so your problem could be caused by the actuating cable slipping.  Another thing to check is the pull handle in your driver's side door jam, make sure that it is screwed onto the cable fully.  The handle tends to unscrew over the years.

Adjusting the latch is easy, once you know a little trick.  Unscrew the latch's cable holding screw.  Looking down on the latch, you should see a small hole, about 3/16" ID, on the left side.  Pull the release mechanism until you can put a punch, drill or other such, into this hole through it's mating hole in the release mechanism. 

Now, pull the cable tight through its attachment on the release, tighten the attachment screw (a little blue Loctite wouldn't hurt), and your done.

Ed Cavalier      EdwardCavalier@pennzoil.com


Headlights - Hazy lens

> On my 1988 Carrera the headlight lenses have a gray haze in them...

I cleaned mine out using windex and paper towels carefully wrapped and taped around the end of a bent wire hanger, going in through the back where the bulb goes.  Cleaned the reflectors, too.  Wasn't difficult at all, and made an appreciable difference in both appearance and light output.

Nill Toulme 
'87 Targa
Atlanta, Georgia USA


Head Studs - Pulled?

"Pulling" is kind of a misnomer.  What's actually happening is that the really strong threads on the steel (or even Dilavar) head studs is "pulling" out of the relatively soft magnesium or aluminum case.

Picture threading a bolt into something like, oh, cheese (or something weird like that) and then apply an axial load ("pull" in engineering terms) to the bolt - it will pull right out of the cheese.  The shear strength of the cheese (not in MIL-HDBK-5, huh?) is so low that it can't react much of a load and keep the threads from essentially ripping the cheese apart...

The only thing that really helps (short of reducing the magnitude of the axial load) is to increase the "shear area" of the threads in the case. Timeserts (or Keenserts, etc.) effectively do this as they require you to drill and tap a larger hole in the case to permit their installation.

Mike Dayton
'76 Euro 911
Huntsville, Alabama

Alexander Caggan, who owns a 3.0, asks what precisely is "pulling" when people say their head studs pulled and they had to spend a lot of money dealing with the problem.

The steel studs pull out of the case, which is made of a metal less strong than steel.  They are screwed into the case, and they strip the female threads tapped into the case.  It appears this did not start happening until engines grew to 2.7 liters with the magnesium case.

Differential expansion is what does this - as the engine gets hot the studs and the cylinders expend.  With early cylinders, which were either steel or aluminum clad steel, and thus expanded at the same rate as the steel studs, there was no problem.   The problem arose after the switch to aluminum cylinders, which expanded more than the steel studs.  In addition, the engines ran hotter because they were putting out more power, or because emissions stuff in the exhaust side heated up the cylinders more.  These expansion forces eventually overstressed and fatigued the threads in the case.

The 3.0 engines and successors have an aluminum case, which is a stronger metal and thus more resistant to pulling the threads loose.  In addition, with the 3.0s the factory began using studs made from Dilavar, an alloy whose expansion characteristics were more similar to those of the aluminum from which the cylinders were now being made.   Plus the factory was able to use other methods than "thermoreactors" to meet emissions, and hence could keep engine heat down some.  According to the authorities on such matters, all these "fixes" meant studs quit pulling with the advent of the SC s.

I have wondered if Dilavar studs are even needed with the aluminum case, though I haven't been willing to use any of my engines as a test subject.  Are the strong but expensive Racewear studs an alloy with matched expansion characteristics, or just strong?

In any event one doesn't hear much about head studs pulling in SC engines, so you can mark that off your list of things to worry about, I think.  It is those of us who bought a 2.7 car, and then at our first meeting with more experienced Porsche owners learned about the dreaded pulling studs, who freak out (more than we need to).

Walt Fricke