04 CTT leaking fuel
08-09-2011, 04:49 AM
#1
Instructor
Thread Starter
04 CTT leaking fuel
Hey Gents, need some help.
Went and fueled my CTT up today and when I returned home had a strong smell of raw fuel around the car. Took a look under and saw fuel on the driver side tank dripping quite heavily. Now when I did the fill up I did bump the gas pump a few times to get that "little extra" as I'm leaving for CA in the morning. The car dripped for only about 4-5 minutes heavy at first and slowing rapidly there after. It was 113 degrees here in Vegas today indecated by the in car temp reading and I DO NOT have a CEL on. I drove the car most of the day after this happened and all seams to be normal.
Could the combination of my overfilling and the high temperature cause an overflow situation or did I bust something?
Went and fueled my CTT up today and when I returned home had a strong smell of raw fuel around the car. Took a look under and saw fuel on the driver side tank dripping quite heavily. Now when I did the fill up I did bump the gas pump a few times to get that "little extra" as I'm leaving for CA in the morning. The car dripped for only about 4-5 minutes heavy at first and slowing rapidly there after. It was 113 degrees here in Vegas today indecated by the in car temp reading and I DO NOT have a CEL on. I drove the car most of the day after this happened and all seams to be normal.
Could the combination of my overfilling and the high temperature cause an overflow situation or did I bust something?
08-09-2011, 09:10 AM
#2
Burning Brakes
Yes.
It is my understanding there are vents and hoses in the filler neck.
As one wrench explained it to me "Getting the extra fuel above the tank and into the filler neck can have negative effects on the sensors and emission system."
You could save a few pennies in gas & refuelling time, but cause a check engine light.
The change in temp increased the volume of gas and your fuel overflowed through the safety overflow.
Whether you busted or damaged your CTT, time will tell.
It is my understanding there are vents and hoses in the filler neck.
As one wrench explained it to me "Getting the extra fuel above the tank and into the filler neck can have negative effects on the sensors and emission system."
You could save a few pennies in gas & refuelling time, but cause a check engine light.
The change in temp increased the volume of gas and your fuel overflowed through the safety overflow.
Whether you busted or damaged your CTT, time will tell.
08-09-2011, 09:22 AM
#3
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I never understood the "get 1/4 cup more gas in the tack" concept. My stupid brother in law literally bounces his car up and down to remove "air pockets" and then squeezes 10 cents more in the tank.
It's not as if he won't stop at a gas station when he gets below 1/4 tank. Why does he need the extra .01 gallon to start?
It's not as if he won't stop at a gas station when he gets below 1/4 tank. Why does he need the extra .01 gallon to start?
08-09-2011, 04:51 PM
#4
Rennlist Member
I wonder the same thing. Maybe, over the course of a lifetime, it adds up to 10 less trips to the gas station.
I'd rather have an extra 1/4 gallon tank just below the regular slot, where I can store enough to get me actually to the nearest station when I run out. I never see the little yellow gas icon until I'm way below the line. Usually coasting to the shoulder...
I'd rather have an extra 1/4 gallon tank just below the regular slot, where I can store enough to get me actually to the nearest station when I run out. I never see the little yellow gas icon until I'm way below the line. Usually coasting to the shoulder...
08-09-2011, 06:16 PM
#5
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Took my 08CTT in for 72K service today. They called me back and said that there is a recall on all Cayennes for a high pressure fuel pump. They did not indicate what the failure mode was, might not hurt to check with the dealer
08-09-2011, 08:52 PM
#7
Burning Brakes
mcbit has it!
The truth about false economy - savings pennies, but wasting dollars of time.
I can understand the OP if he was going from a lower price area to a higher price area trying to save 30 or 40 cents a gallon. But with only an extra 1/4 gallon, only saving $.10 isn't worth the possible damage to the emissions system.
The truth about false economy - savings pennies, but wasting dollars of time.
I can understand the OP if he was going from a lower price area to a higher price area trying to save 30 or 40 cents a gallon. But with only an extra 1/4 gallon, only saving $.10 isn't worth the possible damage to the emissions system.
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08-12-2011, 01:38 AM
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Quite likely the fuel from the underground tank was 20-30F colder then the ambient temps. Once the fuel in the tank reached ambient (or hotter, caused from the heat of the exhaust that runs under the tank).. it expanded enough to blow out the overflow. Unfortunately - the usual path for that is through the charcoal canister, which can destroy the canister breaking it down into a nice soupy mixture that is then sucked into the fuel system when the canister vent opens.
It's a bad idea to burp the gas on any modern vehicle.. and will likely become costly if done often enough.
It's a bad idea to burp the gas on any modern vehicle.. and will likely become costly if done often enough.
08-12-2011, 04:08 PM
#9
Instructor
Thread Starter
Thanks for all the input gents. It looks as if it's only getting worse. It seems to be coming from the highest point of the tank on the drivers side. I think I may have a bad flange? Anyone drop a tank on a Cayenne?
08-12-2011, 08:59 PM
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You don't even want to think about "drop a tank" on a Cayenne (the rear diff and axles have to come out, and perhaps most of the suspension.)
There are access ports under the carpeting under the rear seat. The drivers side has the fuel filter under that port. It locks into a metal flange that is part of the plastic tank. There are sundry hoses and electrical connections that go to it, both outside and inside the tank. There is a rubber gasket that seals it to the flange.
Any of these could be the source of your leak. First step is to cut through the carpet (there are faint marks where to cut), remove the seat-belt mounting (need triple-square drivers to do that) and then remove the plate and SEE what's leaking. Then come back and ask what to do about it.
Meanwhile, I'd park it outside so when it catches fire it doesn't burn your house down.
There are access ports under the carpeting under the rear seat. The drivers side has the fuel filter under that port. It locks into a metal flange that is part of the plastic tank. There are sundry hoses and electrical connections that go to it, both outside and inside the tank. There is a rubber gasket that seals it to the flange.
Any of these could be the source of your leak. First step is to cut through the carpet (there are faint marks where to cut), remove the seat-belt mounting (need triple-square drivers to do that) and then remove the plate and SEE what's leaking. Then come back and ask what to do about it.
Meanwhile, I'd park it outside so when it catches fire it doesn't burn your house down.
08-12-2011, 09:27 PM
#11
Burning Brakes
Are you sure you want to leave it outside??
I can see a smoker flicking their butt under your Pepper and burning that to the ground.
Don't fill the tank for a bit, and prevent the leak till it gets fixed.
I can see a smoker flicking their butt under your Pepper and burning that to the ground.
Don't fill the tank for a bit, and prevent the leak till it gets fixed.
08-12-2011, 10:29 PM
#12
Instructor
Thread Starter
You don't even want to think about "drop a tank" on a Cayenne (the rear diff and axles have to come out, and perhaps most of the suspension.)
There are access ports under the carpeting under the rear seat. The drivers side has the fuel filter under that port. It locks into a metal flange that is part of the plastic tank. There are sundry hoses and electrical connections that go to it, both outside and inside the tank. There is a rubber gasket that seals it to the flange.
Any of these could be the source of your leak. First step is to cut through the carpet (there are faint marks where to cut), remove the seat-belt mounting (need triple-square drivers to do that) and then remove the plate and SEE what's leaking. Then come back and ask what to do about it.
Meanwhile, I'd park it outside so when it catches fire it doesn't burn your house down.
There are access ports under the carpeting under the rear seat. The drivers side has the fuel filter under that port. It locks into a metal flange that is part of the plastic tank. There are sundry hoses and electrical connections that go to it, both outside and inside the tank. There is a rubber gasket that seals it to the flange.
Any of these could be the source of your leak. First step is to cut through the carpet (there are faint marks where to cut), remove the seat-belt mounting (need triple-square drivers to do that) and then remove the plate and SEE what's leaking. Then come back and ask what to do about it.
Meanwhile, I'd park it outside so when it catches fire it doesn't burn your house down.
I found the leak and it's on the drivers side filter port. Strange thing is it's not leaking from the rubber gasket under the flange but fuel seems to rise through the white housing almost as if it has a crack in it somewhere. I had my buddy add small amounts of fuel as I watched and sure enough it's rising up and would then overflow the filter unit. Any ideas as to what needs changed out or is there a valve in there that's stuck open?
08-13-2011, 12:32 AM
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There are no user replaceable parts in the filter assembly.
You need a new one, and the rubber gasket that seals it to the tank. You'll also need to remove and replace the fuel pressure regulator (under the access port on the passenger side) to disconnect/reconnect some of the internal fuel tank lines, so order a gasket for that one also.
There is a special VW tool used to release and reinstall the locking ring for these bits - saw one on eBay for about $60 (don't have the PN any more.. at least not while I'm on the road.) Since you'll be working in the fuel tank, it's to your advantage to run the tank as low as you can without running the tank dry...
It's an ugly job 'cause you're messing around with gasoline.
You might check on ebay for a new filter. I scored a brand new one in a Porsche box for $20 (discount dealer price is around $180 or so - list is over $200) when I was in LA a few weeks ago. The gaskets are around $15/each I think.
You need a new one, and the rubber gasket that seals it to the tank. You'll also need to remove and replace the fuel pressure regulator (under the access port on the passenger side) to disconnect/reconnect some of the internal fuel tank lines, so order a gasket for that one also.
There is a special VW tool used to release and reinstall the locking ring for these bits - saw one on eBay for about $60 (don't have the PN any more.. at least not while I'm on the road.) Since you'll be working in the fuel tank, it's to your advantage to run the tank as low as you can without running the tank dry...
It's an ugly job 'cause you're messing around with gasoline.
You might check on ebay for a new filter. I scored a brand new one in a Porsche box for $20 (discount dealer price is around $180 or so - list is over $200) when I was in LA a few weeks ago. The gaskets are around $15/each I think.
08-13-2011, 04:32 AM
#14
Instructor
Thread Starter
There are no user replaceable parts in the filter assembly.
You need a new one, and the rubber gasket that seals it to the tank. You'll also need to remove and replace the fuel pressure regulator (under the access port on the passenger side) to disconnect/reconnect some of the internal fuel tank lines, so order a gasket for that one also.
There is a special VW tool used to release and reinstall the locking ring for these bits - saw one on eBay for about $60 (don't have the PN any more.. at least not while I'm on the road.) Since you'll be working in the fuel tank, it's to your advantage to run the tank as low as you can without running the tank dry...
It's an ugly job 'cause you're messing around with gasoline.
You might check on ebay for a new filter. I scored a brand new one in a Porsche box for $20 (discount dealer price is around $180 or so - list is over $200) when I was in LA a few weeks ago. The gaskets are around $15/each I think.
You need a new one, and the rubber gasket that seals it to the tank. You'll also need to remove and replace the fuel pressure regulator (under the access port on the passenger side) to disconnect/reconnect some of the internal fuel tank lines, so order a gasket for that one also.
There is a special VW tool used to release and reinstall the locking ring for these bits - saw one on eBay for about $60 (don't have the PN any more.. at least not while I'm on the road.) Since you'll be working in the fuel tank, it's to your advantage to run the tank as low as you can without running the tank dry...
It's an ugly job 'cause you're messing around with gasoline.
You might check on ebay for a new filter. I scored a brand new one in a Porsche box for $20 (discount dealer price is around $180 or so - list is over $200) when I was in LA a few weeks ago. The gaskets are around $15/each I think.
08-13-2011, 08:37 AM
#15
Instructor
I recently replaced the fuel pumps on my 04 and didn't need the the "special ring tool". Its like any locking ring just tap it with a hammer and screw driver to release and tighten. Think toilet locking ring where the wax gasket goes. The new rubber seals are a must. One quick point of advice, vacume all debris up before acutally unsealing. You dont want particles falling into the tank.