10 Most Common Porsche Problems

10 Most Common Porsche Problems

In 1948, they gave us the 356, and ever since, the word Porsche has been synonymous with sports cars and motorsport.

Do not let this fool you into thinking that build quality and reliability suffers at the expense of performance like other luxury brands (we are all looking at you, Ferrari).

Porsche is known for its belief that the only corners that should be cut are on the tarmac.

Roughly 70% of all 911s ever built are still on the road, which is remarkable with over 1 million units sold.

Unfortunately, for the ego of most die-hard Porsche enthusiasts like myself, no auto manufacturer is perfect. So, with the fanboy propaganda out of the way, let's get into some of the common issues you can encounter if you decide to dip your feet into the cult of Ferry Porsche.

Common Porsche problems with 2000+ models

common porsche problems

In this article, we explain some of the most common problems Porsche owners are likely to face. The 911 (996) and Boxster (986) will be included as they were produced until 2005. All of the models covered here are a vast departure from the Porsches of yesteryear.

They are exclusively water-cooled and have a multitude of engine and drivetrain layouts. This also brings the introduction of SUVs and sedans with the Cayenne and Panamera. These cars share a majority of parts with their Volkswagen and Audi cousins.

So, here are some problems you can have with the Porsches of today.

1. Check engine light (CEL)

most common porsche  problems

A CEL is common on any car from any manufacturer. Modern vehicles have hundreds of sensors and modules monitoring every aspect of the engine. If the system discovers a fault, the CEL is displayed on the instrument cluster.

These faults can range from a minor vacuum leak to the car saying, “Remember that pothole you just hit? Now all your oil is on the freeway.” If you want to tackle the CEL yourself, I recommend Durametrics. It is great Porsche diagnostic software to have if you're a shade tree mechanic or a pro. 

If you own a Porsche, it is wise to invest in a good Porsche OBD-II scanner, even if you don't plan on doing the repairs yourself. 

2. Misfires

If your car doesn't plug into the wall, it's going to misfire sometimes. This can be caused by fuel or ignition failures. Spark plugs and ignition coils are wear items and need to be replaced at regular intervals that vary depending on the engine.

When a misfire occurs, a CEL will be displayed; the car will run rough and feel underpowered. Fuel-related issues are harder to diagnose and typically cause the car to not run at all. 

If you have a missife, the first thing you need to do is read the fault codes via the OBD-II port. See this guide for help on how to read Porsche check engine codes. 

3. Oil Separator

The Oil separator on 911 (996) and Boxster (986) have a high failure rate. It is essentially a big plastic box that the engine pulls a vacuum through.

Its function is to collect the excess oil in the system. When this happens, the car will typically smoke on startup or constantly.

4. Immobilizer

Sticking with the 996 and 986, the Boxster was exclusively a convertible until the Cayman (987) introduction, and Porsche sold a ton of drop-top 911s. The problem is the ignition immobilizer is located under the driver's seat.

Porsche must have never imagined that if water got into the cabin that it would pool under the seat and fry the module. Well, it does because the car doesn't have a solid roof, and rubber gets old.

5. Coolant Distribution Pipe

On Cayennes (9PA) and Panameras (970) fitted with the V8, the coolant distribution pipe has a notorious issue. It was originally made of plastic and would crack due to heat cycling.

It runs from the back of the water pump under the intake manifold to the coolant distribution housing at the back of the engine. Porsche eventually updated the part to an all-aluminum construction. But even then, it has rubber O-rings and can still leak.

6. Fuel Smell In The Cabin

This was a common problem on early model Macans (95B). A factory defect normally causes it. The fuel pump cover under the back seat makes contact with the top of the fuel pump housing and rubs a hole in it, letting fuel vapor into the cabin.

Porsche recalled these cars to fix it, but not all cars make it in on recall, so make sure to check service histories.

7. Air Suspension

Porsche air suspension problems

Having air suspension on your vehicle is great until it breaks. This is a costly fix as shocks leak, the pump wears out, and the valve blocks stick.

Each one of those parts is a thousand dollars each to replace easily. Be wary of suspension warnings on the dash; they will kick you where it hurts: in the wallet.

8. PDK Failure

The Porsche PDK dual-clutch transmission will amaze you with its strength and reliability in every car except the 970. The reason the clutches wear out is disputed in Porsche circles. Some say it's the weight of the car. Some say it's the way they're driven.

If you own a first-generation Panamera, this can be frightening as replacements are more than $10,000 as the clutches are not serviceable. 

Common Porsche problems for pre-2000  models

For the uninitiated who don't know before 1998, almost all Porsche sports cars were fitted with rear-mounted, horizontally opposed air-cooled engines. There were a few exceptions being the 928, 944, and 924; these all had front-mounted water-cooled power units.

Air-cooled engines are incredibly reliable for the most part, but advances in technology made them obsolete.

Here are a few common issues you can come across.

No Start: Approximately a million things can cause a car not to start in modern times. Luckily for you, this is not the case with air-cooled Porsches. As a Professional Porsche technician, I can comfortably say that 9 out of 10 times, if your classic 911 doesn't start, it is fuel-related.

Most of these cars have ancient Bosch mechanical fuel injection that is extremely sensitive. Everything is controlled by fuel pressure, and any deviation will cause issues. This normally comes down to either the fuel accumulator or the warm-up regulator. 

Starting with the fuel accumulator, this is a metal canister about the size of a soda can with two ports on top and one on the bottom. This is located on the left side of the engine compartment in line with the fuel filter.

The top 2 ports allow fuel to flow in and out, while the bottom port is used to pull a vacuum on a diaphragm inside. The rubber diaphragm is used to create a kind of fuel reservoir; if this ruptures, it can cause the car to not start. This can easily be diagnosed by removing the bottom line on the accumulator; if any fuel comes out, it is broken.

The warm-up regulator is a small aluminum box with two fuel ports, a vacuum port, and an electrical plug. This is used to regulate the fuel flow through the system. If the regulator becomes clogged, the fuel pressure will spike, forcing the throttle plate closed, strangling the engine. This will normally cause the car to start briefly and quickly cut off.

This can be tested by removing the tank return line from the regulator and sticking it in a fuel safe container. Then you can check it by starting the car; if it continues to run, the regulator is clogged. Keep a fire extinguisher on hand and be very cautious doing this test as it is extremely dangerous having open fuel around a running engine.

Final Thoughts

 

common porsche problems

With all that being said, don't let these issues scare you away from buying a Porsche. By any metric that they are judged, they have set the standard. Sure they have some faults, but on the whole, Porsche cars are one of the most reliable and well-built vehicles on the market.

There is a thriving community for every model, from the 356 guys who can't stop talking about the war to new money Youtube stars, so you can always find a home.

The real question here is not if Porsches are reliable but are you ready to join the cult?

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