mfleming

Does anyone else have the same slight smell of gas in the trunk like I do? I've looked and do not see any signs of a leak. Before I bought this 993 I had a 964 with the same smell. I had the dealer replaced the fuel filler neck on the 964 per their suggestion but that didn't make any difference. Every 964 I've looked at has the same smell.

Kostas Vassiliadis

Are you sure it is gas smell? Maybe smell from battery?

Randall G.

Hello msfleming,

I just had the filler-neck replaced on my 964, because I was having a problem with the gas pump shutting off during fill (sometimes had to reset the pump 5 or 6 times to get a full tank of gas). This problem is now gone, but now that I think about it, I do still smell a faint trace of gas in the trunk.

Here's a wonderful post on this subject, made by Adrian Streather, cut and pasted from the 964 Forum:

Adrian
Member
Member # 113
posted 07-09-2001 05:16

Guys,
Here is the text from the relevant TSB from Porsche. It clearly identifies the fuel
filler pipe as a source of fuel smells and what you need to do. I would check that
you received the correct part number filler pipe if the problem persists. Take it
back and make them carry out the Porsche Test as per the TSB.
Porsche does not provide warranty once the auto has passed its warranty period,
normally!! (they have been persuaded in the past on some issues). These TSBs
must be carried out whilst the auto or model range is still in production and or
under its own warranty. If these TSBs had been carried out in 1994 they would
have been under warranty. This was not the practice of the USA Porsche dealers
as we have already learned. This is the practice here in Switzerland.
Ciao,
Adrian
911C4

Fuel Filler Pipe
Group2
Number
9401
Model
6 Cyl.
Part Identifier2007
March 10, 1994
Subject:
Fuel Filler Pipe
ATTENTION: Service Manager / Service Technician
Models Affected:
911 C2/C4 all
911 Turbo 1991-on
Concern:
If a customer complaint of fuel odor is reported, first check all connections on the
fuel tank, filler pipe and cap for tightness and proper sealing.
Pressurizing the fuel tank with approximately 3 PSI and using an electronic
hydrocarbon detector will find very small leaks which may be possible on the top
of the filler neck or on the hose connections. If the fuel filler pipe shows signs of
leakage in these areas, it must be replaced.
General Information:
If the fuel filler pipe is found to be leaking, only the fuel filler pipe with a metal
band at the top should be used for repairs.
Parts Information:
Description Part Number
Fuel Filler Pipe 964 201 043 03

Warranty Information:
(if applicable)

Damage code: 2007 50 0002

Labor Operation Description
2007 1900 R&R Fuel filler pipe 30TU

mfleming

Thanks for the info guys. I am pretty sure that it's not the battery. It's a specific gasoline smell. From the lack of posts I'll assume that I am the only guy who can't travel to the track without all his race gear smelling like gas. I'll have the dealer take a look and see what they think. They'll probably tell me I need a new filler neck.

Ben in Plano, TX

I also have a mild gas smell in the trunk in my 97 C2S - 49k miles. I replaced the gas cap (it seals were hard and misformed) and it reduced but did not eliminate the smell.

There is no obvious leak and for now I'm living with it - worse problem is leaky valve covers dripping oil on the heat exchangers. Planning to change the gaskets over the weekend.

That's why they call it Labor Day

Anxious to hear what the diagnosis and fix for the gas smell is.

Ben

J-McDonald

My 91 C2 has had this problem since I purchased it. So far, I've replaced the gas cap and filler neck. I've also had the dealer inspect/clean/tighten all of the hoses and connections in the fuel tank. Finally, I had the carpeting in the trunk professionally steam cleaned (in case the odor was trapped in the carpeting). All of this has had little, if any, discernable effect. The next step is to replace the rubber hoses that connect the fuel filler neck to the gas tank and then, if that doesn't work, replace the fuel tank itself. I'll post on the board if I find something that works.

jes999

I get a faint gasoline odor in the trunk of my 1995 993 after filling up, but it goes away within a day. The first few times I noticed it I pulled apart the trunk carpeting looking for the leak to no avail. Now, I've just learned to live with it.

mfleming

So, I am not the only one with this problem after all. I did finally pull everything out to take a look at the battery as well. My vent hose is not hooked up so I'll get the back together and see if it is the issue althought I don't think it is. Without removing the battery I can not see where the hose attatches. Is it behind the battery? I'll take it out tomorrow and see if I can find it.

Mark

johnnypiedras

Thought I would bring this thread up again, and ask has anyone actually fix this problem? This really bothers me, this is gas fuems we are talking about. I have this problem and done all the suggestions and still have the smell.

Martin993

I do have the same gas smell in the trunk ('97 C2S 40k miles) .
Could the PLASTIC gas tank itself be the problem ?

Martin

amfp

Check the hoses in the front trunk, leading to and from the gas tank looking for any signs of old age on any of the rubber or plastic pieces.

Maybe overfilling, and the drain tube for it may be plugged. The overflow drain tube a black plastic fuel filler housing under the hinged filler cover of the bodywork as I recall.

Activated charcoal/carbon filter. Think part is 993.201.221.01 can be another possibility.

But if you don't see the problem, I would say take it in rather quickly and have it fixed by someone qualified.

Anir

I have the same problem, and it has persisted despite two new factory gas caps. The dealer has been unable to solve the problem.

I have found that it is much less noticeable if I only fill the gas tank about 1/2 - 2/3 full, so I'm convinced the gas is escaping from some portion of the filler necks, or soaking the charcoal filter when filled to capacity. Nonetheless, I don't store any gym clothes, etc, in the trunk because they end up stinky.

94twin

I had a similar issue on my 94. At the upper right, under the carpet, I found a crack in the plastic vent cap where the hose connected. As a temporary fix, I used black duct tap to seal off both the hose and the cap until a replacement comes in.

mr5000

old issue, but mine I can even smell it in the cabin if I drive with sunroof open or windows open.
Very strong gas smell in the trunk. Mechanic cant find any leak at all. dont know what to do.

emart

Thought I would revisit this issue again. I read this thread late in 2007 after smelling what I thought was a gas smell in my recently purchased 1996 C4S cabin and in the trunk, much like what has been described in this thread. I posted myself on the issue in November.

I've learned that what most are assuming is a gas smell may be something entirely different.

In November, I had an experienced independent Porsche mechanic who specializes in 993 and older models look at the car mainly for this reason (and noisy brakes!). I watched as he used his gas "sniffing" device (an electronic device) in the trunk and in the cabin vents (both running and shut down). The result - EVEN THOUGH I COULD CLEARLY SMELL IT THERE WAS NO GASOLINE ODOR either in the trunk or in the cabin air system. I wouldn't have accepted this finding if I hadn't watched this for myself.

Further investigation revealed the presence of mold in the cabin air system, specifically inside the plastic "bay" that is located just below the wipers and between the gas tank and the cabin wall. It could be seen when the mechanic removed both cabin air filters to replace them, looking like a dusty particulate substance resting on the bottom of the "bay."

We ended up spraying a disinfectant into the "bay" and wiping it out as best he could, and this corrected the cabin air smell almost entirely. I found that to my nose, the mold odor smelled almost exactly like gasoline. This procedure did nothing for the trunk smell, and it continues to be very strong - to the point I won't put anything in the trunk at all.

I'm really frustrated with this problem. Has anybody had any other success with the trunk smell? Since it smells like the mold odor in the cabin air system, and since its NOT gasoline, I'm considering that it could be mold in the trunk as well. How on earth would you deal with that?

Any comments, thoughts, or ideas would be greatly appreciated.