Porsche Cayenne Buyers Guide
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Get this clear from the start: a used Porsche Cayenne may cost the same as a Porsche Boxster, 996 or compact 4×4 Honda or Toyota from a forecourt, but this is a 300+ horsepower, 2.2-tonne, four-wheel drive people mover that can achieve more than 150 mph top speed. Running costs are appropriate to its abilities, so potential buyers should not expect to run one on a shoestring.
DIYers should also note that Cayenne is no lightweight. Affordable DIY and occasional professional maintenance on a classic 911, 928 or 944 holds few similarities withCayenne running costs. Regardless of how reliable a Cayenne may or may not be in your ownership, things will wear out, some problems require Porsche diagnostics and any work underneath needs a strong, safe lift.
Background to the Porsche Cayenne
By the late 1990s, having regularly teetered on the brink of collapse in recession, Porsche needed to broaden its range with a new product line that would spread the badge beyond its familiar sportscar ranges. To stick with CEO Wendelin Weideking’s product philosophy, any new product had to be high margin, thus ruling out a bargain-basement roadster.
The 4×4 choice came from the multitude of SUVs being produced by luxury competitors: notably Mercedes ML and the BMW X5. When a Porsche customer survey revealed just how many Porsche sports cars shared garage space with competitor SUVs, the plan was sealed.
Porsche could not bear the cost of developing a world-class 4×4 on its own, so it looked for development partners. The first one on board was Mercedes, and the partners travelled well down the road of joint product development until, at the final board meeting to agree the collaboration, Mercedes asked for shares in Porsche, as a gesture of faith. This was unacceptable for Stuttgart and the partnership with Porsche subsequently dissolved.
While not an obviously premium partner, Volkswagen had basic SUV plans on the table, to be developed and retailed by VW and Audi. Given Porsche’s history with VW, in 1998, Porsche and Volkswagen agreed joint development of the pair’s first-ever SUV.
Shared components of the Volkswagen-Porsche SUV would include the bodyshell, ventilation systems and body control modules, but engines, suspension tuning, styling and interior fit and finish would be developed by brand-specific product teams.
When Volkswagen took Touareg assembly to Eastern Europe for cost effectiveness, Porsche opened its chequebook, constructing an all-new manufacturing and development facility in Leipzig, to convince buyers that this was indeed a worthy addition to the Porsche model line up. The Porsche Cayenne would be built only in Germany.
The Porsche Cayenne was launched in 2002 with V8 and V8 Turbo engines. A 3.2-litre Volkswagen V6 came later, which struggles to excite the Cayenne’s substantial weight (more than 9 seconds 0-60). Forced induction adds some energy, but Cayenne Turbo fuel consumption can shrink to single figures when really pressing on. Most Cayenne 955 buyers quickly hone in on the V8 as the optimal solution.
Styled by British designer, Steve Murkett, Cayenne may have a face only a mother could love, but those rounded front and rear ends help it slip quietly through the air at autobahn speeds. The high front undertray gives Cayenne excellent off-road approach angles, while the deep rear bumper easily hides a detachable towball frame and associated electrics.
Wipers hunker down behind the bonnet, sculpted to give a 911-like view across the front wings. Wide rear shoulders allow a spacious tailgate opening, good for bigger items. The sporty rake on the rear screen appears to hinder loadspace, but the rear glass opens separately. Accessory rails sunk in the roof are the mounting points for the ‘load transport system’ (roof rack).
Front and rear park detect are essential options. Headlamp wash is handy, as the lights do get dirty. Non-xenon lamps like a bulb upgrade, and Philips X-Treme H7 bulbs come recommended: the Philips store on Amazon has good prices.
Cayenne’s unfussy interior offers a comfortable environment. Materials are durable, though rubberised soft-touch switch coatings can deteriorate. The leather-trimmed dash is a luxurious option worth having. All switches are signals to control ECUs, hence the turn-on delays. Short horn beeps are impossible!
Heated memory seats, electric swing-away steering column and the multifunction steering wheel are good options: steering wheel light switch is cool. Despite the PCM’s telephone pad, Bluetooth and iPod integration is not standard: aftermarket options offer both, along with postcode navigation. Many PCM units have now been replaced. Bose hi-fi is not super essential.
The standard sunroof is small and drains can leak into the cabin, causing electrical damage to components in the thickly insulated floor. The panoramic sunroof is a nice option but adds quite a bit of weight and complexity. Only non-sunroof is risk free, but see “what to watch” on washer pipes.
Developed specifically for the Porsche Cayenne and built in Zuffenhausen, the now superseded all-Porsche V8 engine is compact – less than 600mm long – and powerful, with a mega-flat torque curve offering 420 Nm all the way from 2,200 rpm to 5,500 rpm.
A three-pump oil system is designed to work on inclines of 100 percent. Sit the car on the tailgate and the engine will keep running: try that in your Range Rover. The closed-deck engine block features additional cast iron bottom-end bearing seats developed for the 928, which also make the engine smoother and quieter.
The cylinder heads follow classic 911 design. The lower section houses the water-cooled combustion chamber and intake/exhaust ports, while the top houses the camshaft and tappet guides. The camshafts run with variable timing: hydraulic controllers shift the inlet cams by up to 50 degrees versus crankshaft rotation. The complex timing chain system is reliable: 250,000-mile Cayennes with silent V8 engines are not unheard of.
Both manual and automatic transmissions are available. While the manual may seem attractive to enjoy the V8, the third pedal crowds the footwell, clutch action is heavy and the shift is laboured. Clutch replacement is pricey and manual transmission saves little overall weight.
The Porsche Cayenne’s Aisin Warner automatic gearbox (above) is also found on the Volkswagen Touareg and Audi Q7, but Porsche’s Tiptronic system brings it fully to life. With manual gearshift available from the shift lever or steering wheel buttons, Tiptronic is the perfect transmission for a V8 Cayenne.
Drivetrain is where Cayenne sits apart from the crowd. Unlike its 50/50-split competitors, two-thirds of engine power goes to the rear axle: a positive contribution to overall feel. Switch off the nannying PSM for harder revs and maximum smiles per mile.
Suspension & Brakes
First-gen Cayenne comes with a choice of steel springs or air suspension. Air suspension gives a comfortable ride, and variable ride heights to help high speed or off-road use, but the coil-sprung option is less complicated and comfortable enough when twinned with 18” wheels. I find most people cannot tell the difference between air and steel suspension on sensible wheels and tyres. Cayennes running big wheels with low profile tyres have a harsher ride, not to mention bigger tyre bills.
Most V8s and all Turbos feature the ‘18” brakes’ option (rear brakes, above): brakes needing a minimum 18” wheel to clear. Cayenne’s brake-hungry reputation may surprise considerate drivers, as quality brake discs and pads deliver reasonable lifespan. A wide range of replacement discs and pads are available in the aftermarket; no need to pay high Porsche prices.
Air suspension comes with multiple warning lights and air cars need to be put into service mode before jacking up, or the system could keep pressurising the affected corner to the point that the airbag explodes. Pressure relief under the bonnet needs doing quickly. The air compressor in the boot makes it harder to squeeze an LPG tank in: steel sprung cars may be better suited to LPG conversion.
Points to Check
All Porsche Cayenne models have a service indicator to stretch out maintenance intervals, but engines and transmissions live longer with regular oil and filter changes well ahead of the service lights. I service my Cayenne V8 with an oil & filter change every 8k miles.
A low proportion of V8s suffer problems with scored cylinder bores: listen for a ticking noise or misfire. While misfires can be coil-related and ticking noises can point to water pump or a cam timing issue, any ticking noise is a no-no. Once one ignition coil fails, the rest may not be far behind, so many owners change coils and plugs as a job lot. There are lots of Cayennes out there, so walk away from ticks.
V8s originally came with plastic coolant pipes under the intake manifold. These eventually fail and drown the starter in coolant. Aluminium pipes are the solution and perhaps a starter rebuild: check yours has been done.
O2 sensors can wear out and cause jolting at low revs. Gearshifts should be silky smooth: harsh changes are a sign that the transmission valve body may be wearing out. Reconditioned units are available. Find a big hill and floor the throttle – any vibration under load points towards a failing propshaft centre bearing (below): replacement propshaft is £350 plus fitting. A preventative change makes sense.
Door mirror casings and replacement glass are expensive: bargain hard for cracked glass and damaged plastics. Later 957 mirror covers are cheaper and fit – albeit not perfectly. They also need different glass. Flat mirror glass on a Cayenne leaves gaping blind spots: eBay wide-angle versions offer best visibility.
Play in the steering or wandering on uneven roads could signal balljoint wear, requiring complete replacement of the front lower arms. Any suspension work needs alignment afterwards to keep tyre wear in check.
A noisy or slow fan means replacement is imminent. Flick the fan speed to max on the heater controls and leave it running for a minute: there should be no change in power or tone. Change fan motor resistors with new fan motors. Change the pollen filter as they often get ignored.
Windscreens are expensive: avoid any cracks. Check that the expensive-to-replace Porsche PCM works with a nice bright screen, and that pricey sat nav discs are present. Adding an aftermarket unit (below) can make more sense.
Not all Cayennes come with a spare wheel, which are expensive to add later. Cayenne tyres are not cheap, with a set of 20-inch rubber costing over £1000. Winter tyres are another must-have, so a second set of wheels is useful.
Weak tailgate springs will need changing (£60 a side). A non-operating rear washer jet means the water is pouring from a split connection in the car and pouring into the floor, en route to drowning the electrics. Blocked front scuttle drains can do the same thing.
My Porsche Cayenne Owner’s Review – John Glynn
After seven years of 4wd Landcruisers and Subaru Legacy daily drivers, I fancied a 4×4 Porsche to use every day. Dominic Delaney at SVP Porsche in Droitwich had happily run two Cayenne V8s for a few years and was upgrading one to a Turbo S. We did a deal on his well-maintained 2004 Porsche Cayenne V8 S with 117,000 miles on the clock, I sold my beloved Subaru Outback and hoped for the best.
Porsche Cayenne LPG Conversion
My Subarus all ran on Liquid Petroleum Gas (LPG: propane), so I had the Cayenne converted to run on propane within a few weeks. The Porsche V8 needs a valve seat lubricant adding to the fuel/air mix: I use JLM fluid at £55 for 5 litres on eBay, which lasts for up to ten months. The biggest LPG tank we could squeeze in the spare wheel well offers a range of 150 miles with my mix of school run and A-road work driving. When the numbers shake out, I get 35 mpg petrol equivalent using all the V8’s performance, which I’m quite happy with. There’s no loss of power when running on LPG.
Porsche Cayenne Running Costs
The only major (i.e. really expensive) issue on my Porsche Cayenne S has been a transmission failure due to worn out clutches, which was sorted with a full strip and rebuild (below), albeit only after I wasted £1000 on a replacement transmission valve body unit from Porsche. Do not make this mistake! Reconditioned valve bodies are available from the highly recommended Valve Bodies UK up in Wallasey. With the gearbox rebuilt, the Cayenne has been great to drive ever since.
Fixing has been mostly replacing consumable parts. A misfire coming away from college one damp night was a coil failing. I changed all eight spark plugs and coils, easily sorted for many more miles. SVP Porsche Service Worcester changed the front lower arms for genuine Porsche from MBS Car Parts and aligned it, transforming the drive on my favoured Continental CrossContact summer tyres.
I have also changed both fuel pumps and the fuel filter: a quick but expensive job at more than £600. At the same time, I replaced a failing front driveshaft for a pattern example which was quite affordable: £120. Of course I have had to change the worn-out propshaft centre bearing, also known as the cardan shaft bearing. An impossible job to do on the floor! This took two attempts to repair, as my first purchase of a supposedly reconditioned driveshaft was totally mis-described.
I’ve fitted Mintex discs and pads: slightly less initial bite than original Brembos but lasting well, and just £200 a car set. I have also replaced the heater blower with resistor (VW Touareg – above) and had a modified towbar fabricated by Racing Restorations in Pershore. I also changed both rear tailgate dampers/gas assistors as they went a bit weak. Not an easy job.
I updated the completely outdated Porsche PCM navigation system to a Kenwood DAB & Bluetooth unit with iPod hook up. I tried an Alpine in-dash sat nav system but was unhappy to have to look down at the display so much. I changed that for a dash-mounted Garmin sat nav with TV tuner etc.
In two years of ownership, I have covered more than 30,000 miles in this Porsche, driving it every day. It looks as good as it did when I first bought it and I love it more than ever. Despite some troubles with reliability, I remain quite attached to it.