Help! Major Fuel Leak on 1999 Z3 M Roadster!

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4pipesalute
Joined: Thu 13 Jun, 2013 21:42
Posts: 28

  M roadster S50

Help! Major Fuel Leak on 1999 Z3 M Roadster!

Post by 4pipesalute » Sat 31 Mar, 2018 12:23

Hi All,

It's been a while since Im posted but I wasn't sure where to turn, so hope someone can help...?

My 1999 Z3M Roadster has been in the garage all winter (in winter storage) and today I started her for the first time reversed her out of the garage. I noticed a smell of fuel but assumed this was just as I have had the car under a cover and it was just ambient 'engine smell'.

However, when I opened the door to get out (with the car still running) I noticed a HUGE pool of petrol on the garage floor trailing out over the garage drive where I had reversed out. I IMMEDIATELY shut down the engine and when looking underneath could see that fuel was dripping of the underside of the car (to the front side of the plastic fuel tank I think). :head:

The car has been in storage from around September/October and it's odd that the first time I start the car this happens! I guess and my initial thoughts run to:

a) Something has perished in the cold weather/over time and a seal or rubber pipe or plastic component has cracked/perished causing a leak.
b) A mouse/rat has bitten though something (I know there are rodents in the garage as I have seen droppings). But perhaps an odd place for this to happen?
c) During this period something has clogged/blocked (such as the fuel filter or a line) and the fuel pump cannot send fuel properly so it has 'burst' somewhere? (It had an Inspection 2 at BMW recently so unlikely also that the fuel filter was old assuming this was part of the service?)
d) Something I have not considered above... as I am not knowledgable enough.

Any help would be hugely appreciated! I have seen 'small fuel leak/smell issues' such as EVAP issues etc but this is a more MAJOR leak. I would say up to 1 litre per minute was leaking.

The leek seems to have stopped now the engine is switched off as presumably the fuel pump is not 'pushing'. But the car is effectively stranded on the driveway now.

Should I:
1./ Attempt to jack the car onto axel stands and inspect, as maybe it's something simple (i'm reasonably competent) or
2./ Hand it to a professional garage to inspect and diagnose and repair.

The car has only done 28k miles from new, so whilst old, is a very low mileage and clean example, so it's odd.

Thanks for any help/advice!!!!

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pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3352

  M roadster S50

Re: Help! Major Fuel Leak on 1999 Z3 M Roadster!

Post by pingu » Sat 31 Mar, 2018 12:41

You don't have to run the engine to see a fuel leak.

With the door open and your hand on the key, turn the key to position 2 (all lights on dash), but don't start. At the same time look under the car. You should be able to see where the leak is. Turn key off when you see the leak. Have a fire extinguisher handy.

If the leak is from above the underbody cover, you will need to remove it to see the pipes leading to and from the fuel filter.
Pingu

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4pipesalute
Joined: Thu 13 Jun, 2013 21:42
Posts: 28

  M roadster S50

Re: Help! Major Fuel Leak on 1999 Z3 M Roadster!

Post by 4pipesalute » Sat 31 Mar, 2018 15:31

Thanks Pingu, I'll have a look. I may need to jack up somewhat as it's hard to see clearly with the car so low and torch angle etc.

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4pipesalute
Joined: Thu 13 Jun, 2013 21:42
Posts: 28

  M roadster S50

Re: Help! Major Fuel Leak on 1999 Z3 M Roadster!

Post by 4pipesalute » Tue 03 Apr, 2018 10:23

So.. fuel seen leaking from the front side of the tank but cannot see up enough to know where it is coming from. I suspect from the top of the tank or where the fuel pump is mounted maybe... One for the garage I think!

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