Porsche Technical Q & A – Highlights of the Most Recent Technical Questions We’ve Answered – Some, No One Knows the Answer to Yet!
We receive thousands of visits every month to our common problems pages. We encourage you to contact us if you don’t find the answer to your particular issue and we do our best to try to find a solution.
We receive hundreds of questions every month in this way and we try to gather them together to identify any trends. The type of question varies dramatically from what appears to be design issues on new cars, to very unusual mechanical behavior. Here are some of the issues that have come up most recently.
Recent Porsche Technical Questions We Received:
Strange Macan Instrument Cluster Issue
Do you use your tirp computer? An owner contacted us in regard to some strange behavior on his new 2020 Macan. Randomly, upon opening the door to enter the car, the trip computer and average gas mileage will reset to zero – quite annoying if you consistently use those items and enjoy the feature. The short version of this story is that it appears some late cars, including the Macan, have this problem and Porsche is trying to develop a software solution that involves the PCM. No word on when that might happen or how many cars are affected.
Engine Coolant Temp Sensor Problems
This month has seen a significant number of issues related to coolant temp sensors. We’ve seen temp sensors that go to zero randomly and faults reported for a temp sensor that isn’t installed on an engine! If you have engine temp sensor issues, do some research into the number of sensors on the engine and check wiring to those sensors thoroughly. Not having a good signal from an engine temp sensor can lead to all sorts of other engine issues.
Transfer Case Warranty Questions
A number of owners have asked how to approach Porsche in regard to the extended transfer case warranty claims for work they have already completed. We suggest going to your local dealer or contacting Porsche NA.
Cracked Cylinder Liner – 997
Two reports this month of early 997 cars with cracked cylinder liners. Both have very different behavior, but both exhibit loss of coolant while running. Both of the owners are working with our partner shops to rebuild those engines – hopefully they’ll choose to enlarge capacity and boost power for a little fun.
Panamera Hybrid Engine Failure
An owner of a Panamera sent us a video of what he described as a ticking sound from the engine. Watching the video, it’s pretty obvious this tick is actually a loud knock and some sort of serious engine failure has occurred. One of the problems with the hybrid cars is the lack of exposure to them in the independent shops. Sales of these cars are low, so while saving the planet is a good idea, finding someone to work on a Hybrid Porsche is not quite so simple.
Turbo Valve – 718
We were contacted by a 718 owner asking about a nasty noise from the rear of the car. The noise turned out to be a turbo wastegate failure. Interestingly, the car did not report any boost faults or engine issues, but the noise was really unpleasant. Very early in the life of a 718 for waste gate failure and thankfully still covered under warranty. One to watch for a common problem in the future.
Cayenne ECU Failure
Check engine light and misfire cylinder 6. The customer had already changed the plug, coil and injector on the cylinder 6 and still had a misfiring cylinder. After a good compression test, the cylinder appeared to have all of the things it needed to run efficiently, however, it continued to misfire. Checking the output from the ecu, the shop discovered no signal from the ecu to the coil or injector on cylinder 6 – no wonder it was misfiring. Replacing the ecu resolved the problem. This is an unusual ecu issue, but it’s important to include the signal from the ecu for the diagnosis of a misfiring cylinder.
Panamera Injector Seals
We made a new friend in Trinidad. The owner described a hissing sound close to the intake when the engine was running. It turned out he had replaced the injector seals with an aftermarket version and the engine had blown those seals out within days of their installation. The hissing sound was air being sucked in throw the seal or lack of seal. Replacing the seal with a Porsche original part solved the problem, but now we have somewhere to stay in the Caribbean on our next trip!
986 / 987 Leaking Water Pump
A number of owners have reported leaking water pumps this month. Maybe the extra use over the summer months has caused a flurry of water pump activity. Sometimes, the source of a leak associated with a water pump is not immediately evident. Even watching small drips appear on the lower water hose connectors does not immediately make their source clear. Check the seal on the water pump regularly on any 986 or 987 Boxster or Cayman – water pump failure can cause engine damage real quick.
Panamera Suspension Failure – throw a blanket over it!
Watch out for shops not well qualified to diagnose air ride suspension on the Panamera or Cayenne. In one recent example, a customer was told his car needed all four shocks and a new pump. We discovered the air pump wouldn’t run and asked the question “how do you know the shocks are bad if you can’t run the pump to fill them?” We recommend a different shop and the problem was resolved with a low-cost relay that activates the pump. The customer saved $3500 on an unnecessary repair.
Panamera – Water Damage From Blocked Roof Drains
If you’ve ever looked at a maintenance interval sheet for a Panamera or indeed a Cayenne, you’ll notice a line that says “check firewall body drains and sunroof drains for debris.” Overlooking this line and not cleaning those drains regularly can be expensive.
We recently heard from a customer who found a good deal of water in the trunk of his Panamera after a rain storm. The cost of the repair ran to more than $8K for the replacement of control modules located at the rear end. We suggest you have a good look at those drains and regularly clean them out.
Lane Change Assist Issues – Macan and Cayenne
A number of owners have reported issues with the Lane Change Assist system on the newer Macan and Cayenne. Porsche has revised the control modules for the lane change assist system a number of times. In one recent example, despite the dealer claiming no issue existed, one owner took the problem into his own hands. At approx 45 mph, LCA would consistently falsely report a warning on the driver side – frustrated with the dealer, the owner took a power washer to the underside of the bumper and solved the problem!