Porsche 911 and GT servicing and repair in Sharjah

This is the most serious item on this page and it is the least dramatic. These cars locate the wheel with one large central nut instead of five bolts, and that nut is tightened to a figure several times what any ordinary wheel fastening sees — which means it requires a calibrated wrench that goes that high and a socket made for it. A workshop without both has two options and both are bad: leave the wheel alone, or tighten it by feel. The second is what produces the cases everyone in this trade has heard about. It is not a difficult job and it is not expensive; it is simply one that cannot be improvised. So we say plainly what the car requires, we use a wrench whose calibration we can account for, and we check the locking arrangement on the nut afterwards. If a tyre shop has had the wheels off one of these and could not tell you the figure they used, that is worth checking before the car is driven at speed.

The 911 puts its engine at the back and its cooling at the front, in low ducts behind the bumper where nobody looks and where everything the road lifts ends up. In a European city that means leaves. Here it means sand, which packs into the fins, holds moisture against the aluminium overnight, and corrodes the radiator from the outside in — and because it happens over years rather than weeks there is no day on which an owner notices. The two symptoms that give it away are both about airflow: a car that cools properly at speed and badly at a standstill is a car relying on ram air because the fans can no longer pull through a blocked matrix. So the pack is inspected directly rather than assumed, which on most of these cars means removing the ducting to see the face of the radiator instead of peering through the grille. Cleaned early it is a service. Left long enough it is a radiator, a condenser, or both, at which point the air conditioning bill arrives with the cooling one.

A dry sump does not keep the oil under the engine. It keeps it in a separate tank and uses scavenge pumps to pull it out of the engine and send it there, which is why these cars can be driven hard through a corner without the pump losing its supply — and it is also why their oil procedure is not the one printed for an ordinary engine. The level is read with the engine running and at temperature, not cold on a dipstick, and a great deal of the confusion we are asked about comes from that single difference: an owner told their engine is consuming oil by somebody who measured it the wrong way, or a car overfilled because a workshop filled it to a figure. So the first thing here is method rather than parts. We check the level the way the car specifies, then look at what the oil pressure actually does under load on a drive, because a warning that appears under cornering load and clears afterwards is telling you something specific about scavenge or supply, and it is worth understanding before anything is opened.

This system does two jobs on one engine: it rotates the camshaft to change valve timing, and it switches the lift of the intake valves between two settings using tappets that lock and unlock hydraulically. Both are worked by oil pressure through solenoids, which means both are sensitive to oil condition and oil pressure in a way a fixed valvetrain is not — and it is why a car that has been left on old oil, or that does mostly short journeys, shows this fault before it shows any other. The presentation is usually mild, which is exactly why it gets ignored or attributed to age. It is diagnosed with live data rather than by ear: the camshaft deviation values read against what the engine is commanding, the switching commanded and observed at the point in the range where it should happen, and the oil pressure confirmed first. Very often the honest answer is that the engine needs the correct oil and a solenoid, not a cylinder head.

A petrol turbocharger that changes the geometry of its turbine housing is unusual, and the reason it is on this car is that it removes the trade-off between response at low revs and flow at high ones. The vanes that do it are a moving assembly sitting in exhaust gas at temperature, and they are moved by an actuator that has learned its own end stops. Two failures follow: the vanes stick, usually part-closed and usually gradually, or the actuator loses its reference. Neither reliably produces a dramatic symptom at part throttle, which is why these cars are so often reported as fine to drive and wrong when pushed — and why a stationary scan finds nothing. So it is diagnosed on the road: requested boost against actual, logged at full load, with the two turbochargers compared to each other. That comparison is what makes the answer obvious, and it is also what stops a good turbocharger being replaced alongside a bad one.

These cars steer the rear wheels as well as the front ones, by a small amount, using an electric actuator at each rear corner — opposed to the fronts at low speed to make the car turn more tightly, and with them at high speed to make it stable. It works well enough that most owners never think about it, which is why the failure is confusing when it comes: the car does not break, it just stops being as easy to place, and the warning that accompanies it names a system rather than a part. The asymmetry is the useful clue, because two separate actuators mean one can fail alone. So it is checked by reading each actuator’s commanded and actual position, then watching what they do on a low-speed manoeuvre and again at road speed, since a unit that behaves on a workshop floor can still fail under load. Telling an owner which corner is at fault is most of the value here, because the alternative is replacing both.