Q- I own a 2000 Boxster and I’ve developed a coolant leak. It doesn’t gush out, it just steadily drips, but I’m losing a quarter-cup a week. It’s leaving small puddles near the right rear corner of the car, and my wife is starting to make jokes about the “puppy that isn’t housebroken yet.” Help! My manhood is at stake here. What do you think it might be?   – Ian

A-   There are a couple of areas that are “common leakers” on these cars, both clustered around the passenger’s rear of the car. The first, and most common, is the coolant reservoir cap. The caps that were put on at the factory were a poor design, and Porsche figured that out pretty early in the game…they made an upgraded cap, that has a little barrier built into it that channels coolant back directly into the bottle. They also upgraded the pressure-relief valve that is built into the cap, to make it longer-lasting.

All coolant caps for modern cars have such a valve built into them…it’s designed to let off minute amounts of vapor pressure during normal operation, and this is part of the feedback-loop that keeps the car running at a relatively static temperature and pressure range. Over the course of a decade or more, this relief valve can get weaker, and start letting off vapor at a pressure that is lower than the operating pressure of the car. It is a safe bet to replace the cap as a pre-emptive measure, and that may take care of your leak all by itself.

The other common leak source is, unfortunately, the reservoir itself. This large, convoluted vessel is located half-in and half-out of the engine bay. It sticks through a hole in the bulkhead, and is covered over by the carpeting and trim in the rear bonnet. When you look at your reservoir cap (with the oil cap right next to it), you are looking at about 10% of the top end of the reservoir. When they leak, they tend to do so on the sides of the reservoir, where you can’t see it without taking all of that trim and carpeting out of the rear bonnet. We often use a light-sensitive dye to help “nail down” reservoir leaks, but this is such a common problem that if replacing the cap doesn’t help, the next best bet is the reservoir itself. This item is expensive…usually about $360.00 for the part, and roughly four hours labor to replace it!  The techs who get this job would like to have a short conversation with the engineer who figured it out. We do not recommend that you try to replace that component yourself.

Unfortunately, the aftermarket has not yet “caught up” on this issue. There aren’t any bargain priced reservoirs being made at present. The only good news is that this is usually a once-in-ten-years sort of problem, so you won’t have to go replacing the thing every season.  MC

Q – While my car was in for service, the advisor told me that the left front wheel did not turn freely and that the warning light is on. They also mentioned that my brake pedal was low and that I needed brake pads (at least). Since I didn’t take the car in for anything related to the brakes, I am a little suspicious. Now that told me what they charge to do brakes on my car, I am even more convinced that they want to sell me things I don’t need. It’s me, George again.

A – Brake quality standards vary widely and so do prices.   On your particular car however, I would call them stratospherically staggering. I know how complex a task it is to service 90’s era Porsche brakes thoroughly and it is painful. Now of course there is an abundance of shops that will do less for less so it is very easy to think that “Back Alley Auto” will do the same job for $300.00 cheaper. Some people think there are only four bleeder valves on the car. Others have told me that when the pads would not fit, they just took them over to the belt sander to make them narrower. There is no limit to the degree of degradation that can be foisted on an unsuspecting price shopper in the interest of netting another “pad slap”.

Does that mean you always need to spend a bundle to get your brakes repaired? Not at all, you should simply have it spelled out with both parts and labor listed to indicate what you are paying for. Call me suspicious but I would avoid any shop that cannot give me a detailed estimate, on paper. As far as your suspicion goes, since you like to work on the car yourself, see if they will work with you to do the aspects of the job that might be outside of your repertoire. Things that come to mind include removing the 16 dinky little button head Allen screws that retain the pad carrier plates, or media blasting the corrosion off the calipers, etc. – MC

Q – I have a 1996 Carrera Cabrio and I have a number of questions. I have had repeated alternator failures in the car. The first one burned up when the wiring harness failed. My clue was that the instrument cluster lit up like a Christmas tree. I had already removed the alternator and purchased a replacement when I became aware of a Porsche service campaign on faulty harnesses. So then I took it to the dealer for the warranty work.

When I went in, even though I had already taken the old alternator out, (which had to be done to fix the harness) they charged me extra to install my own alternator. Shysters! I paid it, under protest, and got my car. About 3 months later, the replacement alternator failed due to a seized rear bearing in the alternator.  They weren’t going to help me, so this time I replaced it myself.

Now two weeks later, it has failed again! It is making the same bearing noise that I heard before. I am wondering what they did wrong or what I am doing wrong. In both instances, I bought Bosch Remanufactured alternators from a local parts house and they were very good about taking the first one back. I really wondered how they were going to feel taking another back.

This time, I took it to an Authorized Bosch Service Center. I wanted the assurance that if it failed again, I could get a parts and labor warranty. I also wanted to know why two of them had failed. I can’t fathom what I could have done differently to make them last. I thought Bosch products were as good as Porsche for a fraction of the price. Now I am beginning to wonder.   Georgel

A – That was an amazing string of really rotten luck!   This is really going to take some time to sort out so here goes: The wiring harness failure is fairly well known, and I will start with the obvious. Porsche did not make that harness. They bought it from a vendor, they specified the level of quality required and maybe they tried a new supplier in “name your favorite third world country whipping boy”. You can bet that the person who signed off on that product has gotten an ear full. I hate to scare you but you were very fortunate that the car did not catch fire. Then again, if it had, your car insurance would have simply bought you another car.

As far as the up charge on the alternator, have you ever been to a fine restaurant and brought in a special bottle of celebratory wine to share? They let you; and when they serve your wine a corkage fee is added to your tab. Car shops are no different than restaurants. Restaurants don’t want you to bring in your own food; car shops don’t want to install your parts, since it costs them money. Next time, simply state your case for having “planned to install it” yourself and not being able to return it. In that case, if it were my shop, I would have either given you a one time pass or charged a corkage fee on the labor.

There is another part of this debacle that I know you know all too well. If you bought the alternator from them, you would have paid more. However, when it failed, they would have had to fix it again for free. So I endorse your decision to pay someone else to do the job, parts and labor both.

As far as the part failure: Bosch has hundreds of vendors who remanufacture their electrical components both in the U.S. and abroad. So in reality, the alternator was (supposedly) built to Bosch standards, put in a Bosch box, and sold as a Bosch Reman unit. They’re not perfect. But guess what, the alternator you get at the dealer is not overhauled by them either. It is again a third party vendor. So it all comes down to the guarantee.

When a part is returned to a parts store under warranty it goes back through a distribution chain and becomes part of the statistical failure pile. A pattern failure, when it is detected, is going to lead to an engineering study to determine what the problem is, but you will never know. Once you take it back, the story is over for you.

When a part is returned to Bosch through the service center warranty facility, each component is dismantled, analyzed, a report is filed, the regional service manager gets a copy, the service center gets a copy, and you as the client will know why it failed. Then they write a check. I prize this information. I trust that at Porsche the same rigorous process takes place. And I like it when I get paid.

When a part is replaced under warranty at a facility, it is far more expensive for the part manufacturer since there is labor reimbursement involved. They don’t like writing those checks, believe me. In the case of Bosch, they pay for labor to diagnose and replace the component and they also pay for the part itself. – MC

Q –  For about three weeks my 1987 944s has been losing coolant but I cannot find a leak. Now I began to notice that my oil is looking odd like a chocolate milk shake.  The car runs fine and it has never overheated.  Any ideas?    Bill

A  –  On the 944 there is an oil cooler mounted on the passengers side of the engine block and by now, most of them have baked seals inside that one cannot see from the outside.  Stop driving the car and have a sample of the oil taken and sent to the lab to detect the presence of coolant.  If the test comes back positive for coolant, have the oil cooler resealed and while it is off the car, have the cooler pressure tested.  I have only seen one cooler actually fail but I have serviced dozens of coolers with failed seals.  By this time in life, any 944 owner should consider it a by product of age and heating/cooling cycles and therefore include it in a maintenance program.

As far as the oily milk shake, once the cooler is resealed, drain the oil, add five quarts of cheap oil, install a new filter, let the car warm up for about 15 minutes at idle, add engine flush (follow the instructions) then drain it and do a proper synthetic oil change .

Caution:  The oil cooler is not the only possible cause of coolant in the oil.  It is just one of many…and the most likely cause.  Had you ever had an overheat, I would suspect a head gasket and on almost any other car, the head gasket would be the most common failing part due to an overheat.  MC

Q –  My 2006 Carerra has an odd symptom with the ignition switch.  To start it, I have to turn the key very hard before it will crank and when I shut it off, I have to push in on the key to get it to turn off.  My other Porsche does not work like this so I am a little worried.  I am also concerned because my last car, a 2001, had an ignition switch failure that cost me almost a thousand dollars to fix.  What am I in for?  Pete

A  –  On the later cars, the mechanical linkage between the ignition cylinder and ignition switch has been eliminated and everything is now electronic.  My first experience of this new design involved receiving a new lock assembly from Porsche with no key.  I thought, “let’s just see if the cars key will work in the new lock”.  I figured it was a long shot but perhaps it was ordered by VIN number.  Nope, the later lock works with any key!  However, although you can insert the key and turn it, you cannot remove the key without plugging it into the wire harness to power up the mechanism.   Now since the only key that I had was inserted into the new lock, and since I had no other keys, I was oh so grateful that the harness plug was long enough to power up the switch and allow me to remove the key.

Once this was figured out, the labor to do the job and parts involved were actually reasonable compared to the older cars.  My advice, don’t wait, get it fixed before it strands you.  And it costs far less than a grand.  MC

Q – My 2001 Carrera began making loud grinding noises and now the low coolant light is on and there is coolant on the ground in the left rear corner of the car.  I am afraid to drive it.  I am somewhat suspicious since I just had the coolant recovery bottle replaced last month.  Matt

A –  Smart move to not drive it.  Two frequently failing components live in that corner of the car;  the coolant recovery bottle and the water pump.  Since you also hear a noise, I am guessing that the problem is the water pump.  Now I know is it an abomination to some die hard purists that a Porsche could even have a water pump but come on, get over it.

The pump is not as buried on your car as it is on some models and reasonably priced rebuilt water pumps (made in U.S.A) are now available.  It is actually easier than on some of the lesser cars that we service which require field stripping the entire nose of the car for access to the pump!   MC

Q –  My Porsche doesn’t seem to have the “get up and go” it used to.  I wonder what I can do to spark up the performance without ruining the resale value.  It is a 1986 944 Turbo.  Todd

A –  Performance is a relative thing so first of all, I would test drive it to see how it compares to others I have driven.  Next I would inspect the car to see if any obvious mechanical problems exist that might cause it to feel a little weak.  If everything checks out fine, I would then plumb in a boost gauge to see what the turbo actually produces and compare it to standards.  Once base line readings are obtained, there are a number of performance upgrades that you could consider.

On line forums are a great place to get ideas but even better is when you can find a local fanatic that has actually done them with success.  See if you can snag a test drive or at least a test ride to see how you like it.  You might also ask him/her what the down side to the modifications might be.   Some commonly used phrases to watch out for are:  “Bolts right on, can easily be done in a weekend with common hand tools”

The beauty of a turbo is that you can have excellent drive ability and massive power at the same time.   But to maintain the resale value you need to take a conservative approach.  The key is to be able to put it back to stock for the next owner.  If your car is in very nice condition now, do not cut, staple, mutilate or otherwise deface the master’s work. I have driven some outrageously fast Turbos that I would not recommend to anyone who does not want to destroy the resale value, not to mention grenade their engine.   Think about the resale value of your turbo with a hole in a piston.  It happens.

And finally, one of the easiest ways to get more power is to simply remove the extra floor mat that is keeping the gas pedal from going all the way to the floor!  Now was that a lucky guess or an astute observation?  I speak from experience.  MC

Q – My 86 944 has been acting strangely and now it is dead. For a while, it would run well when cold unless it was damp outside then it would sputter and run rough but after it warmed up for a while, it ran fine. Recently it started running rough even when it was dry outside after it warmed up. Just before it died, I tried an experiment and disconnected the OXS sensor and it ran better. I was thinking the sensor may be the problem but then just before it died, I heard a loud “bang” under the hood and now it will start but dies right away. What is your best guess? David.

A – Unlike the 911 that died in motion, with this one, I don’t need to guess. All the systems can be analyzed, diagnosed, and corrected “Without Guesswork” (Which is the name of the technical guides published by VW since the 60’s).

The three legged stool of internal combustion engines is made up of fuel, air, and spark. When the car was running rough, the challenge becomes which “leg” is it? If you lose any one of the three, the car won’t run. I would start with an under hood inspection and “smoke test” of the intake system. That bang you heard under the hood was probably a backfire and my hunch is that you blew off a vacuum hose or boot. Any time a loud bang occurs under the hood, you have to check connections and hoses for integrity.   A vacuum leak will upset the fuel mixture. A smoke test involves adding pressurized smoke to the intake which can be easily seen with the naked eye.

Before the car failed altogether, unplugging the OXS sensor would richen up the mixture (“limp-in mode”) and hide a vacuum leak…for a while.   While it is possible for a failed OXS sensor to cause the car to stall, it is very unusual. They usually fail “safe” by causing more fuel, rather than less, to be fed to the engine.   Testing an OXS sensor is not difficult and it can be confirmed or eliminated as a problem fairly quickly.

So maybe you can get the car to start and run by correcting vacuum leaks and replacing the sensor. That does not explain the poor running when wet nor the backfire into the intake. For that a “water test” will often bring out the worst in a secondary ignition system. If it results in misfiring or cross firing of the cylinders, you can blow a vacuum hose or boot off the intake manifold. Spark plug wires, cap and rotor can test within factory spec for resistance and still fail a water test miserably.   If the water test does not kill the engine or make it run rough, look inside the cap and rotor for little black squiggly lines from one terminal to another. When spark jumps across a cap or rotor, it often leaves the tell tale evidence called a “carbon trail”. If you see that inside the cap, or if the rotor has cracks or looks burned, replace them. And since you have an 86, these parts may be original. How do I know that?   These cars are incredibly reliable and usually only need spark plug changes, rarely a major tune up.

In the old days, when I started out, electronic ignition was new and most cars used components called “points” and “condensers”. These parts were job security for mechanics (who were renamed “technicians” a little later). After a tune up, the car would run well for a few thousand miles then gradually deteriorate leading to rough running, poor fuel economy. With the advent of Motronic integrated fuel and ignition systems in the eighties, tune ups became a thing of the past. That is until the age and wear of the parts reach critical mass and the car just dies.

The cure for your car is: seal up the intake system, replace worn ignition parts and test the OXS sensor. With that, I bet your 944 will be humming along like a fine watch for many more years. – MC

Q – I have an 86 Carrera Targa with about 38,000 miles. Recently when it drove it about 10 miles, it started to sputter and then it died. I had it towed in and when it got to the shop, it started and ran fine!  I hate that! They replaced the DME relay, checked fuel pump draw, all other relays and fuses, and could not get it to fail again.   They even test drove it about seven miles without a hiccup.

I was warned that problems that cannot be duplicated cannot be conclusively solved and sure enough, I got about eight miles away and it started cutting out again. Just before it did this, the idle began hunting up and down. Now it is stuck in my garage versus along side the road, but that is little consolation. What’s next? Karl

A – First of all, the DME relay was a good guess but if it won’t act up for the shop, you are at a serous disadvantage.  The other problem is that, unlike modern cars with on board diagnostics, this generation car cannot give you any clues electronically. So you are left with S.W.A.G. (aka: Sophisticated Wild A** Guess) Yes Karl, intermittent failures suck!

Here’s what I suggest: In the engine compartment, there is bracket on the left side of the engine compartment that has two or three fuel injection plugs on it. One of these plugs is for the temp sensor. If the temp sensor has a two connector female terminal plug, but the temp sensor has only one terminal, replace the temp sensor. This is a good diagnostic hunch since these have been known to fail for years.)

The next thing I would check is the main harness plug that connects the engine harness to the body. These rarely give any trouble but you never know and they are easy to check. If the plug is not full seated or if the terminals look funky, that could be it. The next thing I would look at is the Motronic control unit located under the driver seat. Since you have a Targa and since Targas and Cabrios leak, it is possible that the computer got wet. I know of no clever way of getting the computer out without removing the seat, so, have at it! Look for dusty white residue on the circuit board, the connector and harness plug. If you see any, use contact cleaner, then plug and unplug it numerous times to scrape a fresh surface into the terminals.

If none of this works, SWAG dictates parts swapping with a known good car. (Ideally, the owner of the donor car is aware that his is being used for test purposes and you have his permission to infect his car with your problem.)   It is not as bad as it sounds since the infection is easily cured by removing the infected part once the problem is nailed down. Good luck. – MC

Q – My 1997 Targa has only 20,000 miles on it but I have noticed an oil leak in the left rear corner of the engine. My tech has cautioned me that the entire camshaft chain housing might need to be resealed. Wow; that’s expensive! Considering that I only drive the car an average of 1,500 miles a year, I don’t know if I want to budget that much at once.

The other issue is that the front wheel hubs on the car are extremely corroded! My mechanic had a tough time getting them off.   My car is pampered!   What can I do about it? Joel

A – In regards to the cam chain housing leak; it could be bad indeed. Before any decision is made, the area needs to be thoroughly cleaned and dried. Then, oil leak detection dye should be added. The last one I inspected was a mess at first glance. But following the cleaning, the stud grommets were found to be the major leak source. There was also an allen head bolt/plug found loose. Four of the stud seals were easy to replace. They had shrunk from age and did not fit the stud tightly. Bear in mind there are more than four studs but the others are tough to reach.   So a compromise was made for an 80% improvement at minimal cost. To correct the other 20% would have involved several hundreds of dollars.   The cliché’ that applies is “the cure may be worse than the disease”.

On the topic of rusty hubs, although you may think you pamper your car, there’s an area you’re missing. I know you never drove the car in the winter or even when it was raining. But when you walk out to your garage and look at your beautiful sleeping showroom beauty, you need to keep in mind that you’re making her sleep on a stone floor without a mattress. Your garage floor is, all by itself, a hostile environment for your car. I am no snob but bare concrete brings out the worst in steel and aluminum components especially when they are bolted together. My garage is carpeted and maybe yours should be too. Mine has a vapor barrier (plastic) under the carpet. That’s what will keep the hubs (and any other exposed metal components) from rusting in the first place! But, if they have already, the cure for is a hand held sandblaster inside a custom made hood followed by a coating of cold galvanizing compound.   Then apply a thin coating of anti-seize compound between the hub and wheel.   MC

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