98 V70: Sticking Fuel Level Sensor

Post by **sleddriver** » 07 Feb 2018, 14:00

Lately, it's been acting up, leaving me to wonder just how much gas I have left. I've also noticed that when filling the tank (motor off), the fuel gauge will rise, hang, rise, hang...slowly ratcheting itself upwards. Searched the RD last night. Found plenty of hits for AWDs but they're quite different. No photos of the interior either on the one I did find for FWD. I'll be taking a photo when disassembled.

Also, the dreaded P0455 has raised it's ugly head and refused to surrender. Might be time to replace both FP and sending unit's tank seals. Might also be a leak where the filler pipe joins the tank. None of these + the tank hoses have ever been replaced. I have noticed that when I fill-up, I can smell gas in the garage the next morning....but only when I completely fill-up. Following that, it would seem to be a leak on top of the tank somewhere. Advice? Suggestions?

Finally, one MVSer said immediately screw the ring back onto the tank after removing either the FP or sending unit to prevent the tank top from expanding, which would make screwing it back on later much more difficult. Interesting that....

Also said don't use silicone grease on either the seal or the threads. Use Vaseline instead. Interesting that as well!

Teddy1975 · Post by **Teddy1975** » 07 Feb 2018, 15:27

sleddriver wrote: ↑07 Feb 2018, 14:00 None of these + the tank hoses have ever been replaced. I have noticed that when I fill-up, I can smell gas in the garage the next morning....but only when I completely fill-up. Following that, it would seem to be a leak on top of the tank somewhere. Advice? Suggestions?

Finally, one MVSer said immediately screw the ring back onto the tank after removing either the FP or sending unit to prevent the tank top from expanding, which would make screwing it back on later much more difficult. Interesting that....

Also said don't use silicone grease on either the seal or the threads. Use Vaseline instead. Interesting that as well!

You shouldn't need to use any lubricants on seal or threads. And yes, do put the locking ring back on the tank while you work on the pump. The vapours from the gas can expand the opening to the point where it's almost impossible to get the ring back on, even after only an hour (Stated in VADIS, and I can unfortunately vouch for that from personal experience).

The smell of gas could be from a detoriating hose, you should be able to tell when you can get to the top of the tank. There should be no smell of gas until you remove the rings freeing the sending unit and pump.

Good luck,
Teddy

Post by **misha** » 07 Feb 2018, 15:56

About fuel level sender:
viewtopic.php?f=1&t=56052

About P0455....could be that something is disturbed from your recent accident at the back of the car.

Post by **sleddriver** » 07 Feb 2018, 17:33

misha wrote: ↑07 Feb 2018, 15:56 About fuel level sender:
viewtopic.php?f=1&t=56052

About P0455....could be that something is disturbed from your recent accident at the back of the car.

I remember seeing your post. A photo of the inside would have answered a few questions.

No, P0455 had been plaguing me long before the recent accident.

Post by **sleddriver** » 07 Feb 2018, 17:36

Teddy1975 wrote: ↑07 Feb 2018, 15:27The smell of gas could be from a detoriating hose, you should be able to tell when you can get to the top of the tank. There should be no smell of gas until you remove the rings freeing the sending unit and pump.

Only smells when filled full. This may also be due to the fact that liquid gas has flooded the rear-mounted char-can and given enough time (overnight) vapors escape from the open shut-off valve.

Both the ABS and EVAP systems on this car have been a constant PITA......