Q – My 1976 912E has a number of issues and I think I need professional help. I enjoy working on the car, it has over 300,000 miles on it and I enjoy driving it just as much as my newer Carrera. Here’s the deal. The sunroof will not shut all the way. I have replaced the cables, cleaned the tracks, lubricated the motor, adjusted it until I am blue in the face, and still it won’t close. That’s the first issue.
The next problem is my oil temperature. When the engine is fully warmed up, I can’t drive it too far without the oil temp getting to ¾ up on the gauge and I am worried about burning the engine up. The engine is a “crate motor” purchased from the left coast and I had it installed a couple years ago at a local shop. It has no thermostat so I do not think that could be the problem. I have checked and set the timing, set fuel mix and I am out of ideas.
The next issue is a lack of power. I have had another 912E and it ran much better than this one. Having checked everything that I know how, I need help. Brad
A – As a professional, I may be offer you the help you need for the car, but you may need another kind of professional help for the passion that you feel for this particular model and the fact that you enjoy working on it. I sympathize. I too have been criticized for my taste in cars and my fascination with fixing them. So call us both crazy.
For problem one, the one part you do not mention is the transmission, not the one that drives the car, the one that engages the sunroof cables to the sunroof motor. That little bugger has an internal clutch and when it fails, the sunroof will not close all the way. It takes a greater amount of torque to close the roof compared to opening it. Try this. Can you shut the roof using the tool that the factory provides? If so, and this is going to hurt, a new transmission is about $500.00 and you might need one. If you or anyone can tell me how dismantle and repair one, I would really like to know, otherwise Porsche is the only way to go.
On problem two, oil temp is controlled by the thermostat mechanism and oil cooler working together. When your thermostat was removed, did they also remove the directional flaps? If so, you should pay that shop a visit and ask them to kindly reinstall them for you. Years ago, when I was young and ignorant, I believed that thermostats were unnecessary and added complexity for no value. Now, with a better grasp of the engineering involved, I never suggest that a thermostat system be eliminated. Not only will the oil cooler not receive the air flow it needs, the engine will take forever to warm up, This causes excess wear, bogging on acceleration and poor fuel economy.
For problem three, short of having a dyno where you can measure fuel mixture under loaded conditions, I strongly suggest that you install a wide band OXS sensor to monitor fuel mixture. Your engine may be getting lean at highway speeds which can spell disaster to your valves and rings. For a proper diagnosis of this issue, you really do need professional help! More on this topic next month. MC
Q – My power steering has failed on my 924 S. When I look where the belt should be, not only is it gone, so is the pulley that drives it! What the heck? Bill
A – Well, that was an easy diagnosis. Here’s what happened: Either the bolt that holds the pulley in place has fallen out or the drive pulley has fractured. If the bolt fell out, you are in big trouble. Don’t drive the car until you know!
The other possibility is that the pulley for the power steering sits on a relieved area of the crankshaft which centers it. It is held in place by a cup washer and giant bolt. My bet: when Billy Bob’s Backstreet Garage installed it, the pulley slipped down off that relief just slightly off center. When the giant bolt was tightened, the pulley got bent. The warped pulley would drive the power steering pump quite nicely though it and they probably thought nothing of it. Eventually the wobbling pulley will crack, then break and fall off the engine. The part is no longer available from Porsche and I am hording all the used ones I can find. –MC
Q – My 944 lost its power steering after a trip to the body shop when the car was being repaired for about a month. Now when I turn the steering wheel, it gets tight at 180 degree intervals. They claim that they did not touch the steering and I don’t know why they would have had to but now it steers terribly. Bruce
A – A very simply way to determine if your power assist is working or not is to turn the engine off and try to rotate the steering wheel then start the car and try it again. If you notice a marked difference in effort, the power steering is working. The clue to your symptom is the 180 degree intervals. The steering shaft has two universal joints that tend to get rusty and bind. When they do, you notice it every half turn of the wheel when the angle is the most acute. As your car sat at the body shop, when the humidity got to those exposed universal joints, the problem surfaced. It is not their fault. The part is simply failing.
You can lubricate that universal jointed shaft with penetrating oil or grease and this will probably alleviate the binding for a while. In the long run, you will need to replace the shaft or joints. When the seals fail, and the grease washes away, rust sets in. Sooner or later, the joint will loosen up and create slop in the steering wheel. I have never seen one broken but driving with loose steering is very disconcerting to me and on a Porsche, utterly unacceptable. –MC
Q – I have a Cayman S and I plan to take it to Grattan later this month. A friend suggests Pagid brake pads for track use and I wanted your opinion about this brand and compound. I also want to drive it on the street so I am looking for a good all around pad for both modes. Alex
A – Finding a good all around pad for Grattan and the street is an oxymoron. The problem with race pads on the street is that they are noisy and squeak frequently. The big problem with street pads on a longer track is that they cannot take the constant heat and can boil the brake fluid or damage the calipers, not to mention burning the pad to cinders in just one track run!
Pagid “Yellow” pads are very highly thought of in the DE community. To fit the Pagid pads, I have solicited some important comments from our Cayman brake expert, “Mr. X”, regarding Pagid Yellow RS19 pads: 1) The pads will need to be “milled” or “shaved,” they are too thick to fit in the calipers as-is. The pad wear sensors will not fit into the pads as-is. We would recommend “jumpering” the sensors while at the track. It’s important to secure the sensor harness so it doesn’t get damaged. The use of the OEM stick-on shims for the backing plates of the pads is not recommended on the track. The tremendous heat generated by the brakes will melt the adhesive, and very likely warp the shim plate. These shims are meant for street pads and daily-driving use.
So there you have it. I suggest that you buy two sets of pads, street pads and race pads. Take the race pads to the track or install them just before you leave for the track. When you get home, install the street pads so you won’t annoy your neighbors. –MC
Q – My 996 Twin Turbo has a problem with the clutch pedal and clutch engagement. The pedal feels very odd and drops very low until I start the car then it pulses after the engine starts. Once the car is running, the clutch is difficult to engage smoothly. I have gotten used to both problems but I still wonder about them. When I let other people drive it, they stall the car and complain about how it works. Steve
A- Your car has an unusual clutch system since it is a turbo. On most cars, the clutch is manually operated with your left foot providing all the power to disengage the clutch and engage smoothly. In most applications, the system works fine and rarely has a functional problem. Sometimes the clutch pedal may squeak and after a few years, it may bind. The turbo, on the other hand, is a different animal. Since Porsche did not expect your left leg to have the strength of a gorilla, they designed the car with a power-assisted clutch slave cylinder.
The first symptom you describe is often due to a failure of the accumulator which stores hydraulic fluid under pressure providing power assist on start up. When an accumulator fails, the system will still work with the engine running and the pump functional. As soon as you turn off the engine, pressure drops and the pedal will feel odd. The rough engagement could be due to an internal clutch issue, the clutch slave power unit, or both.
The power-assisted slave unit carries a price tag of near $1,000 and a few hours of labor are needed to replace it. The unit is attached to the transaxle with a number of bolts and nuts that are extremely difficult to reach. Research online describes how to fabricate custom wrenches with a cutting torch and grinder just to get at them. The part was installed onto the power train before it was installed in the vehicle. Replacing it will be expensive, especially if you have a shop do the work.
An alternative would be to eliminate the power assist assembly and install a standard clutch slave cylinder. The part is amazingly inexpensive but there is no getting around the labor to surgically remove the original unit. It is not a simple bolt-in swap since you do have to block the pressure fitting, but that is not too difficult once you find the fitting that it takes. The strength needed to operate the clutch is manageable but noticeably stiffer. If you wife ever drives the car she won’t be happy with your choice. –MC
Q – I am just starting to get my 76 911s running again after being in storage for six years. One issue I’m dealing with is tires. My 15-inch rims use 205/70vr15 tires. I need new tires and these seem to be difficult to find. What size comes close in a modern tire? Dave
A – I checked with my tire advisor who I have worked with for 30 years and he suggested a couple choices. In the original size, there is nothing that I could locate in a “V” rated tire, only an “H” rated tire. FYI: V rated tires have a top speed limit of 149 mph and H rated has a 130 mph max rating. If your car runs as well as mine, you need the V rating. The rating does not only indicate the max speed it also relates to the construction of the tire for stability at higher speeds.
On the other hand, you can opt for a slightly smaller diameter tire such as a Kumho LX Platinum which is V rated and the size is 2156/60VR15. Your original tire had a height of 26.3 inches and he new ones will be 25.1 inches tall. This will have the added benefit of better acceleration and handling compared to the original tires. I like the Kumho’s because I choose moderately priced, sticky tires that have a low tread wear rating for my car. I do not track it or put very many miles on it so I expect the tires to rot before I ever wear them out. For your purposes, you may find other fine choices but now you have an option. –MC
Q – Last year I bought an ’81 911SC that had 8 broken Divalar head studs. I went through the engine myself and had a mechanic that worked for a Porsche dealer in the past go through the transmission. He put in new syncros on all gears and new drive dogs on 1st and 2nd. Everything is back together and running but I am having a couple of issues with the trans.
When trying to put the trans into first gear while at a dead stop it is common for it to not go into gear and other times it just falls right in. If it does not go in I will let the clutch out depress clutch and try a second time, may need to repeat a couple of times and it will go in. Shifting into second (up shift) sometimes goes in good sometimes not. Down shifting into second you can very distinctly hear the small whine that goes with a syncro getting pressure put on it and again sometimes falls right in and other it takes a fair amount of muscle to get it in gear.
At this point, I’ve put in about 500 road miles on the rebuild, and only third, fourth and fifth behave as they should. I have rebuilt all of the shifter linkages and have set the shifter coupling so that 3rd and 4th go into gear just to the left of the 5th / reverse gate. I changed the gear oil and found the oil to be dirty, what I think is a normal amount of metallic “mud” on the magnetic drain plug and a few shiny metal fines. I then tried a different gear lube with no apparent change. After initial clutch adjustment, still encountering the hard shifting on first and second gear; I set the clutch a little on the high pedal side to ensure it released. This produced no change. Both conditions seem to be worse when trans is warm.
The guy that went thru the trans said I should give it some time and see if it gets better. If not he will go thru it again but said I would need to buy OEM sycros for first and second instead of the aftermarket ones I provided from Pelican parts. He said if the problem is not corrected by this, he’d blame the syncros. I wouldn’t try to tell him, “The Master Cylinder told me…”, but I am looking for somebody with more expertise than I to tell me if this sounds right. The thing I find odd is the problem in 1st and 2nd, given that those are the two gears that recieved new drive dogs.
Help! – Terry
A – I hate to tell you this but it sounds like it may have to come apart again. It sounds as if you have done everything externally that you can do.
The syncro whining you describe could be caused by a clutch that is failing to disengage. I have heard it before, many times, so that would be my bet. I think it odd that you would be seeing mud or metallic filings in the oil after a rebuild but I suppose it depends on the method and depth of cleaning.
You need to get a second, hands on, opinion before pulling the trigger. I would suggest that you take the car to an independent tech who has decades of experience with older cars (with all due respect to the guy who built it). Again, although it sounds like a clutch issue rather than a trans issue, I would need to experience it to speak intelligently about it.
I do not think the syncro origin is a likely factor although aftermarket parts are sometimes not the bargain they appear to be. I also suggest that next time you farm a portion of the work out, let the tech source the parts. You usually don’t save enough money to offset the diffusion of warranty responsibility, especially on a huge job like this. MC
Q – My ‘89 Carrera will not start and I have checked everything. I have also taken all the advice of the web experts and fired volleys of parts from the “parts cannon”, still to no avail. I have spark, fuel and the engine cranks normally. I am fit to be tied, what do you recommend? –Chuck
A – Does it start on ether? If the answer is yes, you need to verify that strong signals being produced by the sensors and see that the injectors are receiving a pulse. Since your car does not have self diagnostics, you may have taken it as far as you can. Antiques like yours sometime require sophisticated test gear that is out of the price range of shade tree mechanics. At least you might not need to buy many more parts! –MC
Q – My 2003 Carrera recently began to run rough, the Check Engine light came on and started flashing. I shut it off and when I started it back up, it ran fine again but now the light is on all the time. I wonder what might be causing this and if it is safe to drive with the light on? –Sam
A – The check engine light indicates critical issues by flashing. When the engine started running rough it was probably misfiring. You were smart to turn it off and restart it. Doing so, reset the computer misfire detection. Driving after you restarted the car is not an immediate problem although eventually the misfire will come back. When the light comes on, if the engine feels strong and runs OK, you can drive the car to a shop to have it scanned and diagnosed. I suspect that when this occurred it was cold or wet. Don’t be surprised if it happens again during torrential April showers.
Driving with a misfire may do some damage, so when the computer detects a miss it will temporarily stop the fuel injector pulse at only that cylinder. This protects the cylinder from getting washed clean of oil by the fuel. It also prevents raw fuel from entering the catalytic converter which can cause the cat to overheat.
On newer models, there are two common problems that I find. One is oil-soaked spark plug coil packs caused by a failure of the spark plug tube seals. The other is failure of the coil pack itself caused by a faulty manufacturing process which leads to cracked insulation. On many of the coil packs (there are six per engine) the steel component is exposed to humidity which causes them to rust, expand, and crack. Fortunately, they are not too expensive to replace. When the coil packs are replaced, I suggest replacement of the spark plugs as well since they are also not expensive and easily accessible with the coil packs out.
Incidentally, on older pre-OBD (on-board-diagnostics) cars—the ones without a check engine light—the computer will not shut the fuel injectors off! The effect can be much more dramatic with a great likelihood of expensive damage. On these cars, driving with a misfire can only make it worse. It is best to tow the car rather than drive it. With the older cars, replacement of the spark plugs is essential. Experience has shown that even if the misfire is cured, a previously fouled spark plug will usually re-foul. –MC
Q – I own (what I consider to be) a classic 1980 Porsche 924. It has been in my family for thirty years and I love the car. I have had dozens of chances to replace it with a newer car but I plan to keep it forever. I recently learned that I am not alone. I discovered people like me who love these cars and see them as I do…a classic. As I learned more about the origin and evolution of the design I felt even more proud to still have a survivor. I would like to bring it to some club events but I wondered: If I bring an old car like mine to a drive, will everyone turn up their noses at me?—Mickey
A – I am glad that you recognize your car for what it is: A classic. In my opinion, a classic is in the eyes of the beholder. Dozens of 924 and 944 owners that I know will cheerfully tell you why their car is special. Years ago, many in the classic car world felt that the 356 was just a VW on Viagra and it was not considered a very good looking car either. It only took on classic status decades later. Many 356s were used, abused and discarded like yesterdays trash, but not anymore! It may be a long time coming, but eventually your 924 might be considered as much a “classic” as a 356 is today. It certainly is a better handling and far more practical Porsche.
I know some will say, “that so and so MC is just running his mouth again. How dare he compare a 356 to a 924” but the history of both cars is rooted in a common lineage, VW and Porsche. Just as the 356 dipped into VW parts bins for front axle components, steering, transaxle, engine, electrical components and lighting, so does the 924.
Those familiar with the original 924 will see VW Rabbit control arms, Super Beetle front struts, VW Beetle rear suspension, VW bus rear axle joints, an Audi 4000 transaxle and the ultra reliable Audi and VW 2.0 liter engine used in light trucks in Europe! Starting at the parts bin has proven to be a very successful strategy for Porsche in designing and building their “classics” which began as affordable sports cars. The sheer endurance of the design and the longevity of production speaks highly of Porsche’s commitment to the 924 concept which spanned 19 years.
True, the earlier cars were rough around the edges and the engine was not what it would become in later years, but just like the 356, Porsche never stopped improving or building on the basic platform which reached its pinnacle in the fabulous 968! So stand proud, you belong in this group and you are welcome to join the party. One or two people may look down their noses at you, of course, but the club is home to many different personalities and interests so don’t let that stop you. Many Porsche club members have been wondering about me for years. Maybe it’s the bib overalls, maybe it is my VW connection, but I will welcome you to the Porsche club as will the vast majority who appreciate everything Porsche. –MC