I haven't done that job on an E46, I did it on my E30. After some tugging at lines under the car while having someone watch, I was able to identify the line underneath. I spliced the new hose to the old one and pulled the new hose into position. Make sure to use a quality high-pressure hose and clamps, you don't want to do the job twice.
Warren

 

I’d go with the advice warren gave above my reply. Make sure you use quality hose clamps though. In my experience many of the stock ones are 1 time use and shatter when removing then. I’ve had good experience with Koehler clamps from autozone, nothing expensive either.

 

Thanks for the responses guys.

Just to be clear, on the E46 this fuel line is not just a rubber hose. It is mostly a hard line. See pic.

The line that I believe is leaking is the longer of the two in the pic. So I have some concern as to whether or not it can be replaced without dropping the tank.

 

I bet the old hose is fine but the factory crimped hose clamp is loose. Replace with jubilee clamp

 

I've had tanks leak on top- the most frequent cause has been at the plastic sender to rubber hose interface, too.

Often, there's a 'parting line' in the molded plastic, and as Sapote notes, the factory clamp loosens
as that line of plastic sinks into the rubber hose. Then it leaks right along the mold line.

Sometimes the nipple breaks as the plastic deteriorates, occasionally the hose breaks down a litte,
often the seal on the top of the tank (where the sender seals to the tank) leaks,
but I've not yet had trouble with that hard plastic.

Unless you have mice. Then all bets are off.

Dropping the tank's not that terrible- getting the filler connections off is the worst part.

But I'd diagnose (compressed air is great for this) VERY carefully to prove
the line's bad before I dropped the tank.

hth
t

 

More than likely came apart where the rubber hose is crimped onto the hard line.

I can see were they meet in the pic. Not much room to be able to cut the line and run a longer piece of hose.

Best would be to drop your tank and replace the line properly.

 

More than likely came apart where the rubber hose is crimped onto the hard line.

I can see were they meet in the pic. Not much room to be able to cut the line and run a longer piece of hose.

Best would be to drop your tank and replace the line properly.

That is my thought as well, that it failed at the junction where the rubber is crimped onto the hard line.

Just to clarify, though... the tank has to be dropped to replace that line? It looks like I could possibly thread it through there and have a second person grab it. But Ive never messed with the fuel lines on the E46 before, so maybe that's wishful thinking?