Strong petrol smell inside and outside CLS350CGI M272

[clk208]

Hello. Long time no post, family life with young kids has been minimising my forum reading time for a few years.

On the Mercedes front my W213 estate is gone but I still have my trusty W219 CLS which has been pretty much no trouble over almost 13 years of ownership.

As we get into the colder weather, there is a strong smell of raw petrol for a few miles until the engine is fully up to temp. Come to a stop at traffic lights and you have to put the window down it's that bad. For maximum effect, if I drive a 1 mile journey to the local post office, switch the engine off and get out of the car it absolutely stinks of petrol, even from 20 feet away. Getting back in it's an intoxicating smell of leather and petrol like stepping into a 1970s Jag. The smell is less with the interior fan switched totally off.

Fuel consumption is good (well as good as it has ever been) so it's clearly not leaking like a sieve but something is definitely very wrong. The performance of the car is spot on - rapid and responsive at all points in rev range and regardless of cold or hot. No engine codes with my basic code reader.

Any intel on where these M272s like to leak fuel from and any insight on why it's only appearing in colder weather? I had a similar issue last year but then stored the car off road for the worst of the winter and it has been fine through the warmer months until now.

 

[SpikyMikey]

Different engine, but my 204 with the M274 lump had a very similar issue, likewise more noticeable in cold weather. In my case it was the flexy pipe that spans the gap between the solid fuel line that runs from the tank to the HPFP mounted at the back of the engine. May be worth finding where your High Pressure Fuel Pump is and tracing the plumbing back.
Possibly significantly in my case, the replacement part and hose clips were of a modified design.

 

[clk208]

Different engine, but my 204 with the M274 lump had a very similar issue, likewise more noticeable in cold weather. In my case it was the flexy pipe that spans the gap between the solid fuel line that runs from the tank to the HPFP mounted at the back of the engine. May be worth finding where your High Pressure Fuel Pump is and tracing the plumbing back.
Possibly significantly in my case, the replacement part and hose clips were of a modified design.

Excellent shout, thank you. I'll locate that HPFP and see if there is anything to note.

I've just read @E55BOF 's thread about a top end oil seep on the M272 giving a smoky oil smell in the cabin too and wondering now if I have two issues - a petroly and an oily smell so that's something else for me to try to get a visual on.