Porsche Macan Forums

Hi all,

Just driven home in my 21 Macan S and had a worrying experience with the car - I’ve already booked into the garage for Friday but wanted advice in the meantime.

Car was fully up to temp and I was accelerating onto the motorway, giving it a bit of beans, then once it hit between 5-6k rpm, it developed only what I can describe as a misfire/severe jerking up and down on the revs and then the amber engine warning light came on, driving permitted. I got home but it wouldn’t allow me to accelerate any more after that. I can’t underline how violent the jerking was…I’m confused as to what’s going on - I’ve only done 8k miles and worried it’s something serious.

My wife’s Merc had something like this a while ago and I had to keep gas on the throttle and left foot brake it home. It seemed terrible but was a faulty air bleed valve (something like that) and then the ECU reacting to it because it believed it needed to protect the engine.

When we took it to the garage if behaved normally and nothing showed up. Fortunately as the engineer took it off the ramp the issue reoccurred and they hooked the analysers up. Once the valve was replaced the car returned to its normal self.

This is the warning I got - thing is, I turned it off and it goes away but as soon as I set off again and started to bring the revs up, it came back on. So will the dealers computer pick it up even if the warning isn’t on again?

The only way I can describe it was like hitting a rev limiter / fuel cutting out. I literally just filled up with a full tank of Esso Supreme unleaded, could it be a bad batch of fuel?! I’ve never experienced anything like this before.

I believe these errors are logged and remain readable, could be wrong others will soon shout if so, but it's under warranty so relax, probably nowt anyway!

It’s highly unlikely to be anything serious. My mate had a cayman throw a serious wobble not unlike what you describe. It took a while to diagnose but turned out to be a wonky crankshaft position sensor which supplied the ECU with erroneous info causing all sorts of issues with ignition & fueling. Please do let us know how you get on.

Dodgy fuel is not unheard of, storage tanks can be contaminated, possibly by water. Hope you still have your receipt. But as others say it may be a faulty sensor and is likely to have recorded a fault code.

Macanori wrote: ↑Wed Jul 27, 2022 10:43 pm This is the warning I got - thing is, I turned it off and it goes away but as soon as I set off again and started to bring the revs up, it came back on. So will the dealers computer pick it up even if the warning isn’t on again?

The only way I can describe it was like hitting a rev limiter / fuel cutting out. I literally just filled up with a full tank of Esso Supreme unleaded, could it be a bad batch of fuel?! I’ve never experienced anything like this before.

What I want to know is how you get a reading of 500+ on range. My highest so far (3 fill ups) is 420.

I can only assume I got this range as I just brimmed the tank and as it went into limp mode, I couldn’t accelerate even if my foot was flat on the floor. Assuming that’s what it was?

Quick update:

It’s been diagnosed by my Porsche garage as having a faulty high pressure fuel pump - so essentially the car was being starved of fuel at high revs. Fortunately managed to get a video of the revs when it was happening to show the technician. The part has been ordered and is getting changed next week so I decided to leave the Macan at the garage as don’t want to drive around in it anymore like that.

Anyone else had / heard of this fault or have I just been unlucky?

Macanori wrote: ↑Fri Jul 29, 2022 5:19 pm Quick update:

It’s been diagnosed by my Porsche garage as having a faulty high pressure fuel pump - so essentially the car was being starved of fuel at high revs. Fortunately managed to get a video of the revs when it was happening to show the technician. The part has been ordered and is getting changed next week so I decided to leave the Macan at the garage as don’t want to drive around in it anymore like that.

Anyone else had / heard of this fault or have I just been unlucky?

Not on the Macan ( yet, anyway ). I did have it replaced on my 335i as a recall item.