Porsche Cayenne Common Problems
Heavy Gear Shifts or Coolant Leak?
Listed below are Porsche Cayenne common mechanical problems with their likely resolutions. These are the most frequent Cayenne problems diagnosed by our repair shops over the years.
An accurate diagnosis of an issue by a Porsche mechanic typically saves you time and money – see our guide to local independent Porsche repair shops that can help. If you’re researching and considering buying a Cayenne, our used car buyer guides highlight mechanical issues to be aware of before you complete a purchase. If you are considering making a DIY fix to the problem, the best resource for step by step guides is here.
Clicking each section will open more detail.
955 | 957 | 958
Porsche Cayenne owners experience a heavy downshift from the transmission. In many circumstances this can be accompanied by much louder gear changes and clunking from the transmission. The problem is often mis-diagnosed as a physical failure in the transmission itself when the more likely cause is in fact the valve body assembly within the transmission. usually, replacing the valve body saves the transmission and returns normal smooth gear shifts.
A coolant leak can be deadly for any engine – overheating of the engine due to a loss of coolant very quickly does damage that could result in a total failure and an engine replacement being needed. The coolant pipe failure in the early Cayenne typically happened quickly and produced large amounts of steam.
The original V8 Cayenne engine featured a series of plastic cooling pipes that ran front to back through the valley of the engine below the intake manifold.
Running plastic coolant pipes underneath the intake manifold seems like a reasonable idea, until you realize these pipes are made from a plastic that can’t handle the hot environment they live in. Once they degrade and a leak starts it quickly speeds to a point where large clouds of steam can be seen billowing from under the hood when the engine is running – steam powered Cayenne!
There is an update kit available to permanently fix this problem and change the plastic pipes to metal ones. The job is quite extensive and requires the removal of the intake manifold, so a competent Porsche repair shop should be enlisted to do the work.
Water Pump Failure – Water pumps fail regularly. The bearing in the pump supporting the shaft wears and the shaft starts to wobble. This develops into a knocking noise sometimes accompanied by a coolant leak. Typically, this will show up initially as a continual engine temperature increase at idle, although when driving the car may maintain a better temperature. Not addressing this issue promptly can lead to hot spots within the engine and result in cracked cylinder liners or a total engine failure. The repair is straightforward.
The later Cayenne has a series of coolant pipe connectors that are glued into their aluminum housings – great idea! Like all glue, over time the seal begins to fail and coolant leaks out. There are two likely spots for this to occur – the front of the engine or the rear of the engine close to the transmission joint.
Front Engine Coolant Leak
The leak at the front of the engine is most likely from the upper front coolant pipe which slips out of its housing when the glue fails. Porsche revised the design of the replacement part to be bolt in so the problem should not return. This issue is common and typically runs about $500 in parts.
Rear Engine Coolant Leak
The leak at the rear is much more of an issue. Almost all Cayennes experience a failure in a coolant hose connector at the back of the engine close to the firewall. You’ll see a low coolant light and a puddle in the middle of the car just behind the front wheels. The rubber system hose is clamped to an aluminum insert in the housing that distributes coolant between the cylinder heads. The glue fails on the aluminum insert and coolant leaks out. The replacement part is updated with a screw in insert for the rubber hose to connect to.
The problem is getting this new assembly attached to the engine. Porsche recommends engine and transmission removal, which puts the cost for this minor leak into big money territory! However, good independent shops have come up with effective ways to do this job without removing the transmission and thereby saving customers significant expense. If you have this leak, search our Porsche Repair Shop listing to find a locally skilled expert that can solve this problem for you more cost effectively.
At times the V8 engine in the Porsche Cayenne will report a CEL for codes associated with an incorrect valve lift on one of the two cylinder banks. There are two reasons for this – one obvious and one less so. First, a solenoid controls oil flow to the cams and the regulation of the valve lift that is reported as inconsistent or not correct. On many occasions replacing the solenoid will solve the problem. However, if the solenoid replacement doesn’t solve the problem, you could be left scratching your head as to why the report of incorrect valve lift returns.
The answer lies in a not so obvious location. Valve lift is determined by the front O2 sensor. Under acceleration the vale lift is increased and the front O2 sensor sees a gas flow content increase within a range. A failing front O2 sensor will either not see or cannot react to the valve lift gas flow change quickly enough within the tolerance the engine management system requires and therefore a valve lift fault is set. Replacing the front O2 sensor typically will solve this problem.
Associated with a CEL and rough running, the earlier V8 engine can experience a dead cylinder. Of course, replacing the plug and coil is the first step but, if the problem persists we’d recommend compression testing the cylinder involved. Commonly, an intake valve lifter will be stuck or broken and will result in an intake valve being stuck open. If you’re lucky, this can be solved by replacing the lifter. However, in many cases the valve keepers will also break and the valve contacts the piston. This requires the removal of the head and valve replacement.
On occasion, the older V6 Cayenne will develop a vacuum leak and set a CEL. There can be many causes but one of the most common is the failure in the PCV system usually caused by a failed diaphragm in the separator on the valve cover. Unfortunately, the separator is built into the valve cover and cannot be replaced individually. The repair requires the replacement of the whole valve cover.
Generally affects vehicles produced between 2010 and 2012 model years. The problem lies in the aluminum bolts that secure the timing chain sprockets to the camshaft adjusters. These engines have adjustable cam timing systems. The timing chain drives the adjuster which varies the position and rotation of the cam based on engine performance demands. Unfortunately, the bolts holding the adjuster to the cam break and allow significant free play. The result is a loss of timing on the camshaft and in some circumstances significantly worse outcomes such as a catastrophic engine failure can occur very quickly.
Porsche was required to recall 2010 through 2012 vehicles to correct this problem. If you are looking at a model in those production years, you should definitely check for evidence the recall work was completed. More information on the recall at http://www.camshaftadjusterrecall.com/
Hybrid models. Some drivers have reported that their vehicle accelerated unexpectedly. The car will surge forward even when the brakes are applied. We recommend visiting the Porsche dealer urgently if this problem occurs for you.
Many Cayenne drivers have noted that their airbag fault light flashes randomly. This known problem and is often caused by a faulty connection to the module under the driver seat. This can be caused by corrosion on the connector likely from water entering the cabin via the window or wet shoes.
As with any safety system, don’t assume the problem is minor – have the problem diagnosed professionally at a competent shop.
Fuel pump failure on the Cayenne is very common. Older models have two in-tank pumps while the later models also have a high pressure fuel pump driven off the camshaft.
Failure of the in-tank pumps is very common. Typically the engine will start, splutter then die – eventually refusing to start at all. This is caused by the pump overheating very quickly and shutting off. Generally, in the early Cayenne this will not be seen through diagnostics, however a simple fuel pressure test will reveal the problem.
Porsche has updated both of the in-tank pumps a number of times and when having this issue it makes sense to replace both the pumps and associated filter in a single job.
High Pressure Fuel Pump
On the later engines with direct injection, the high pressure required to deliver fuel comes from a pump driven by the engine. The failure shows up in the same way as with the in-tank pumps, however, sensors on the engine will report low fuel pressure conditions.
The key is diagnosing this correctly – the mechanical pump does fail commonly, however, if no fuel is being delivered from the tank it will be unable to build pressure for delivery. A good repair shop can accurately diagnose this for you.
A common problem in the Porsche Cayenne is a condition where the climate control fan suddenly starts working intermittently, only at one speed or not at all. The variation in the speed of the fan is controlled by the blower motor regulator. Once the regulator fails, a single speed fan is commonly the result. With no speed at all or a noisy fan, it’s also possible the blower motor itself may have failed. Diagnosing which one of these conditions you have can save you money – replacing the regulator is cheaper and easier to complete.
ABS or PSM failure can be serious. This is a safety system that needs to be diagnosed accurately by a professional. However, one of the most common causes of the failure in the earlier Cayenne versions, was the wear in the brake light switch.
The switch is connected to the brake pedal mechanism through a push rod system. Over time the plastic wears down the the brake signal is lost – this causes the ABS and PSM system to go into a fault status. Replacing the switch is pretty straight forward.
The older Cayenne will often have a noisy drive shaft accompanied by clucking sounds on acceleration or when switching gears. This is usually caused by a failure in the driveshaft support bearing. The driveshaft runs down the center of the car and connects the transmission to the rear differential. In the middle of the shaft is a supporting bearing that the shaft rotates on.
When the center support bearing fails, the shaft wobbles, vibrates and thumps during acceleration. You’d be hard pressed to find an early Cayenne that hasn’t experienced this problem or currently be somewhere close to experiencing it again. Porsche’s replacement for the bearing wasn’t much better than the original.
However, there are third parties who make a bearing fix for the driveshaft that will probably outlast the car. The aftermarket solution does not require the driveshaft to be removed to complete the job and usually will save you money on the repair.
Cayenne Chassis System Failure
This fault becomes evident on your dashboard when a malfunction occurs in the air-ride suspension system. The system has a number of components, but generally, only one failure indicator. Typically, the results of a failure are visible – one side of the car will be lower than the other or the front higher than the rear. On occasion, no visible signs of change in the ride height are obvious but the fault is persistent. In colder climates, the fault can be sporadic initially, based on air temperature.
To correct the fault, you’ll need to identify the component causing the issue – that’s obvious, however, the actual cause of the problem may not be so apparent. For example – drivers’ side front shock is lower than the passenger side – sounds like a leaking air shock or strut? Maybe, but it could also be a ride height sensor, leaking hose, faulty valve block or bad electrical connector!
Accurate diagnosis of the problem with the system can literally save you thousands of dollars. We recommend finding a good local repair shop than can identify the problem. Interestingly, a shop that has a good degree of Mercedes Benz experience is a good bet. Mercedes air ride systems have been exhibiting the faults that are now common on the Porsche air suspension for many years, so most good independent shops with added Benz experience can spot the real cause of the problem quickly.
Components and Failures
The air compressor supplies the system with compressed air. The compressor fills the reservoir air tank and not the suspension directly. The compressor is designed to run in short bursts to top off the tank.
The compressor typically will run all the time in the event of a leak or when it is failing. Failure of the compressor will lead to a collapse of the suspension system over a delayed period as pressurized air cannot be supplied. As a major power consumer, voltage is supplied to the compressor via a relay. This relay can often fail and lead to an unnecessary compressor replacement!
The air supply tank is the least likely area of failure. This simply stores the compressed air to enable enough volume to be delivered quickly to correct the vehicle ride height. The tank supplies air to the system via the valve block – a hole in the line from the tank to the valve block will cause a system wide failure.
Compressed air is supplied to the valve block from the air tank. The valve block is an electro-mechanical device that routes pressurized air to the individual system components per instructions sent from the control module. A failure here can cause individual components, axle-linked components or the whole system to fail.
Air lines or hoses
The air hoses travel from the valve block to the individual system components. Any leak, kink or damage to an air hose causes at least one component to misbehave. Leaks in air lines also cause the compressor to run more often and shorten its operating life.
Front Air Shocks or Struts – Rear Air Spring
The air ride shock, strut or spring is filled or indeed emptied of compressed air via the air hose and valve block. Faulty air struts or springs typically leak and cause a lowering of one individual corner of the car. Two failing at the same time is unusual, so if you have a lower than normal ride height across one axle, do not assume leaking struts – see level sensors below. Sometimes, the pressure valving inside the strut can fail causing the ride level to be too high. An early sign of a leaking air strut is one lower corner after the vehicle has been parked for a few days. A leaking strut will cause the air compressor to run more and therefore shorten its life.
Each of the suspension components has an electrical connector. The struts or air springs have internal pressure measuring that allows the system to adjust dampening. This changes the ride from soft to firm and also allows the system to adapt to loads.
The electrical connectors can become corroded or greened in some circumstances. This causes the system to report malfunctions but typically does not affect ride height. Ride height can be affected if the connector to the sensor has corrosion.
Ride Height Level sensors
The ride height sensor is a small electro-mechanical component that connects the suspension to the body of the car. A small plastic arm translates vertical vehicle movement into rotational movement in the sensor. Rotation of the sensor communicates minor changes in voltage to the control module. Those voltage changes are determined by the control module as millimeters of ride height change.
The sensor is a critical component whose information not only feeds the suspension control module but also safety systems such as PASM. Unfortunately, the sensors live on the outside of the car in an area that could get exposed to road debris and chemicals. Failure of these sensitive components is inevitable.
Ride height sensor faults can be fun! A dead sensor is straightforward to diagnose – no signal. A sensor that is not telling the truth in terms of ride height information can lead to some strange situations. Because a ride height signal is still reaching the control module from a faulty sensor, action is taken based on that faulty information. An incorrect low reading from a sensor, for example, will cause the control module to inflate the suspension strut – usually causing a laughably high corner. Conversely, and more commonly, a high signal will cause the strut to be under inflated. This looks like a leak and is commonly mis-diagnosed.
Suspension Control Module
The suspension control module runs the whole system and communicates information to other vehicle systems. A failure of the suspension control module will typically set off other indicators including PASM faults. The control module is one of the least likely items in the system to fail. A typical failure will be a complete shutdown of the suspension. Control module failures rarely cause part system failure.
Switch failure is commonly overlooked. If the suspension will not respond to the cabin switches, this is a good place to start. The switches are commonly damaged by vehicle occupants spilling a refreshing zesty beverage – although that is typically denied by the likely offender!