fuel gauge/fill issue?

The last two times I have filled my 2002 C4 Cab the pump nozzle has clicked off and I have topped it a bit and then gone on my merry way, only to notice the gauge is registering 3/4 full. I talked to my mechanic who indicated (in his opinion ) that this is not a typical problem. I also had one fill up where it just kept clicking off and I eventually went to another station thinking it was the pumps problem, now I am thinking different? Next time I fill up I will take it down to almost empty and measure the fill. I just wanted to see if you guys have experienced a similar issue?

This is a common problem. My car never registers more than 7/8 full no matter how much fuel, even when fuel is up into the filler neck.

This happens to me from time to time. I believe its related to the strange shape of the fuel tank (it is kind of like a U shaped around the front differential on the C4 and C4S).

Make sure you don't leave your engine running while filling up. I read that can cause similar issues.

My '99 never shows "Full" either. Not the end of the world for me, just odd. I am not going to lose sleep over my misreading

My 99 has never showed a full tank. Always about 3/4 full. I have had the car the last 7 years and done 50,000 miles in it with no major problems.

I always fuel my 996 using the lowest/slowest notch on the nozzle handle, stop filling on the first click, and never top off the tank. Fuel gauge shows "full" ten out of ten times with this process. /X3

2003 C4S checking in. Many times mine will click that it's done but only be 3/4 full. I can usually pull the nozzle out slightly or just adjust it a bit and finish it up.

My 99 does it as well. And my low fuel light comes on at just under the 1/4 mark. #annoying

Mine shows full. I did learn on my first fill up to NOT top it off as gas spewed everywhere pretty much as I started slowly pumping after the first shutoff. I have to fiddle with my G35 to get it full after the first shutoff.

Mine has never showed full, always 7/8ths and even when driving with the light on for a long time, I still cannot get more than 15 gallons in the tank. The reason is because the gauge requires calibration due to how it works: it guesses at how much fuel is in the tank due to the tank�s irregular shape. The calibration procedure is non-trivial. One way to fix it didn�t work for me: fill the car all the way up (one-click refill), disconnect the battery for 15 mins, reconnect.

Same experience as techsavvysam in post #10. Always shows full and don�t add another drop after the click. Learned my lesson the hard way as well.

2004 C4S I have had the same partial fill issue. Found a trick that works every time but it�s tedious: push in the gas nozzle and hold the handle UP so the tip of the nozzle touches DOWN in the filler neck. When it finally clicks, it�s always full. Going for one more �click� to top it off results in an embarrassing spill (�doot-de-doo, don�t mind me while I stand here and hold this while gas drips out under my car...�) I used to drive old Mercedes diesels and always had to be careful about foaming while filling. Seems like a similar effect in my C4S. My theory is that holding the tip of the gas nozzle against the filler pipe makes for a nice smooth flow so no bubbles or foam. Could be wrong but the mental model works for me every time.

^^ There are two separate issues. One is the gauge that�s wrong. In this case, the tank is full, but the gauge shows 7/8ths. The second is the issue you are describing, which is the inability to fill the tank completely from the nozzle. I�m sure some people might confuse the two, especially newbies because there�s no easy way to figure it out.

Rotate the nozzle so the base is at 9 o�clock. You have to hold it there. Read this a while back. Either here or Renntech. Works for me.

^^ That might help solve one issue, but won�t solve the other.

Fuel nozzle clicks off when tank not full, have to repeatedly pull handle to fill. Fuel fill valve on top of filler neck may be bad, and another way to temporarily address is install $10 Porsche adapter available from Pelican and other suppliers: https://www.pelicanparts.com/More_In...assCat=Y&null= Arrives in Porsche bag with no instructions how to install. Pelican website has instructions but missing key piece of info: https://www.pelicanparts.com/techart...stallation.htm After installation tank filled normally without clicking off early, but got CEL and code probably because it caused a leak at gas cap. With a fair amount of force pushed adapter further down until notches on filler door side just above collar and notches other side just below. After that reseating, tank twice fully filled then properly clicked off, and 300 miles later no CEL. Picture doesn't accurately show notch on right side just above collar, on left side just below. When adapter seated here tank fully fills before clicking off and no check engine light. Long-term will learn more about fueling system and determine if there is another problem to be addressed.