Fuel tank problem - 986 Forum - The Community for Porsche Boxster & Cayman Owners

ctbmj · 05-28-2005, 08:35 AM

I have a 2003 986S purchased in the U.K. If the fuel gets low and 'Check Fuel' warning comes up and I then re-fuel to full, the gauge does not re-set when I drive off, and the 'fuel remaining' figure on the OBC continues to drop until it becomes blank (indicating dangerously low). Sometimes the gauge resets itself to where it should be some time later in the journey, but usually this doesn't happen until the next time I drive the car from cold.

Turning off the ignition and restarting, as recommended by the local OPC does nothing. Otherwise, they have no suggestions. Most likely suspect seems to be tank sender (sticking float?) or signal conditioning software. Could it be cables in tank mentioned already in this forum? Anyone else had this?

Many thanks for any help.

Tool Pants · 05-28-2005, 09:20 AM

There is a bulletin for your year. There are pipes in the tank and the float can sometimes get hung up on them after refueling. They are supposed to tie the pipes out of the way. Your OPC should know this.

RandallNeighbour · 06-12-2005, 06:34 PM

ok, now I am frustrated.

Paid my mechanic for an hour's labor to tie wrap the cables in the gas tank to allow my fuel indicator to work properly.

Before he did this, it would only read 3/4 of a tank when full, then fall as gas was used so I could at least see when to fill up.

Got it back from him, and went to fill up and enjoy the full tank indicator for the first time since owning the car a year... it stayed at 3/4. Grrr.

Got on the freeway and sat in the heaviest bumper to bumper traffic I've endured in a very long time... and at 95 degrees outside. I looked down and my fuel level was at full! Well, I thought it had finally kicked in. Good!

Today I drove around a couple of hours and put about 110 miles on this tank of gas and it's STILL at full. Grrr.

I am guessing I should just replace the sending unit. I think I'll call LA Dismantlers and see if I can buy one used. I don't want to pay $175 for this part. It's stupid.

Toolpants, do you have any pictures of accessing the fuel sending unit so I can see them and do this little job myself? I searched renntech and didn't find any, nor did I find any here.

Tool Pants · 06-12-2005, 09:55 PM

The tie the pipes out of the way of the float level sensor is for 2002 up because Porsche changed the fuel delivery system that year when it went to the 'returnless' system. Not your year.

The sending unit is under the battery tray and held in place with a locking ring. This is the VW/Audi tool to unlock it. Your mechanic must have it.

I would not buy a used sender, if it is your sender. It could also be a problem with your instrument cluster. This is a Peter question before you start throwing money at the car.

RandallNeighbour · 06-13-2005, 05:59 AM

Thanks Jeff. Here's some info you may not remember you helped me with a year ago:

1. The instrument cluster is brand new. I had to buy one because one of the digital numbers on the speedo was out (far right one) and it bugged me so much I had to do it. The fuel gauge indicator acted the same on the original cluster as with this one, so I do not believe it's the cluster.

2. From the link below from a technical article on Pelican parts, I thought it was five bolts, not a special tool as you have pictured for the 1997. I'm not arguing with you by any means (You're the expert, not me!) but I wonder if I should just take a look anyway. This guy took out his sending unit, cleaned it up a bit and put it back in...

http://www.pelicanparts.com/techarticles/911_fuel_tank_sender_replace/911_fuel_tank_sender_replace.htm

Thoughts? Comments?

Tool Pants · 06-13-2005, 09:17 AM

The Pelican article is not for a Boxster. The tool in my pic is also shown in the Boxster shop manual. If you remove the battery tray you will see the locking ring. It 'unscrews' like the lid for a jar.

RandallNeighbour · 06-13-2005, 09:37 AM

Is it possible to unscrew the unit by hand or with another tool I might use that wouldn't chew up anything? I'd really like to do this myself.

And I'm guessing I have to remove those hoses and the electrical plug that are attached before I go unscrewing the unit, right?

mccarthy · 11-20-2006, 12:57 PM

Quote:

Originally Posted by ctbmj

I have a 2003 986S purchased in the U.K. If the fuel gets low and 'Check Fuel' warning comes up and I then re-fuel to full, the gauge does not re-set when I drive off, and the 'fuel remaining' figure on the OBC continues to drop until it becomes blank (indicating dangerously low). Sometimes the gauge resets itself to where it should be some time later in the journey, but usually this doesn't happen until the next time I drive the car from cold.

Turning off the ignition and restarting, as recommended by the local OPC does nothing. Otherwise, they have no suggestions. Most likely suspect seems to be tank sender (sticking float?) or signal conditioning software. Could it be cables in tank mentioned already in this forum? Anyone else had this?

Many thanks for any help.

yes i have exactly this problem. have you found a fix?

thanks

mark