Rotmilky

I've noticed recently that when I start the car and get out, I get a really strong whiff of fuel outside the car. There are no drips that I can see, but with the underbody panels, I'm sure they're blocking any leaks. The smell seems to be strongest in the front wheel wells. I smell nothing in the engine compartment nor do I smell anything in the cabin. So I'm guessing the leak has to be coming from somewhere near the fuel tank.

Anyone have a guess as to what might be causing it. Currently the car is up on jacks and I'm pulling the underbody panels. I need to replace the clutch, figured I'd fix the fuel issue while I was at it.

Rotmilky

Well cruddy crud. Underbody panels pulled and now I can't get any gas smells. Wouldntcha know it?

The only difference I can think of is that the car has maybe 1/4 tank of fuel in it. I noticed the smell last weekend when doing an autocross and I had just filled the tank up before going (I was trying to get weight over the front tires). Is there some sort of overflow hose on the gas tank (or maybe fume collection system) that might slosh fuel through when the tank is full and I'm driving an autocross. That might explain the smell at the last AX. Doesn't really explain why I was smelling something on startup.

Macster

The fuel system has a pretty complex ventilation system to not only keep the tank from venting fumes while in use, when sitting parked, and even when filling the tank.

Given the emissions requirements you should not smell fuel at any time from the car, except perhaps at cold start you might get a whiff of unburned gas in the exhaust.

There is a fuel leak. I can't tell you where the fuel leak is but you need to find it. If you only smell fuel after hard driving there might be a fuel vent line with a crack/split that allows some fumes to escape but otherwise shuts tight enough the DME doesn't detect a leak in the fuel ventilation system. If I'm right, this can be a pretty hard leak to find.

You can if you want and it may not be a bad idea to eliminate other possible leak sources/explanations just in case it is something else.

(Do you make it a habit of overfilling the car with fuel? Do you bring the level up to the brim or even a bit over?)

Might not be a bad idea to remove the battery cover and the panels on either side and give the area where the fuel pump bolts into the tank a good inspection looking for leak sign or odor.

Rotmilky

My thought is that there's a fuel leak too. I don't over fill the fuel when refilling. Once the nozzle clicks off the first time, I don't add more. (It's been my understanding that continuing to put fuel in the car beyond the first click will mess up the vapor collection system). Maybe I'll try pulling the upper covers to see if there are any leaks on top of the fuel tank. I guess worst case I'll just leave the underbody panels off until I can recreate the problem.

texas_maverick

Did you change your gas cap recently?

Andrew 987

Dear Texas Maverik
I have same problem showed from Rotmilky and I have replace gas cap recently .... do you think that problem is this change ?
From that replacement I have noted this problem ....

Let me know pls .
Thank you to all

ugame

Just adding another to the list. Cayman S 987.1 with low millage. Fuel smell. Porsche dealership confirms it's a leak from the tank and would like $8000 fine Australian dollars to replace the tank.

I'm looking into options from reputable third party workshops.

Another common fault is the sender unit, but they didn't check this. They think the join at tank for the filler neck has failed, and they're also not sure if the collar inside the tank has also possibly failed.

I'm actually shocked that such a crucial component of a prestige brand is this prone to failure. Very surprised to find this thread with so many others in the same boat.

Yay German engineering.