Fuel-fill saga in XC70

[Silvestris66]

I have a 2003 XC70 with a fuel-fill problem that's been driving me crazy. To fill it, I have to stand at the pump for over 10 minutes, holding the fill valve the whole time, with gas trickling into the fill neck. I can hear air escaping back up the neck, and if I go too fast, it will foam up and shut off the pump. It's been this way since I bought it from my sister.

I checked the hoses near the fuel inlet for spiders. That's not it. When I gave up, I mentioned it when I took it to a well-known and reputable Volvo specialist in town for another issue, and they took a look at it. They also checked for spiders and did a pressure test. They said they thought it was a stuck rollover valve and that they would have to drop the gas tank to fix it.

I recently had them replace the oil/air separator, and they were supposed to fix the refueling problem. On Friday night, it was almost out of gas, so I went to fill it up, and to my frustration, the problem is exactly the same as it was before I paid to have it fixed. I won't be able to talk to the mechanic until after the July 4th holiday is over. They were very busy when I picked up the car, so I didn't have a chance to talk to the mechanic about what he'd found.

I'm completely at my wit's end with this. What the hell could be wrong with this thing?

[shin91]

Hey there, i have this issue as wellin my 2005 xc70. It happens to some petrol stations that use old pumps with the analog meters.
The newer pumps have no issue; before throwing money at it try to find a petrol station with newer (digital) pumps and give it another shot.

[kef]

Can you elaborate on the foaming? Have you tried multiple gas stations (as mentioned by shin91? Gas fill nozzles these days have vapor recovery systems that should take the vapor that escapes the fill hole.

[Silvestris66]

I live in North Carolina where gas pumps don't have vapor recovery systems, and, yes, I have tried this at probably over five different gas stations.

I have to fill it slowly enough that you can see each digit changing on the hundredth of a gallon display; in other words, you need to be able to see 1 changing to 2. And you can hear air being displaced up the fill tube. If enough gas goes down the fill tube to block the escaping air, it foams back up.

I'm not sure why people don't believe that this is a real issue. From what I understand, during fueling, air is supposed to leave the gas tank -- I think -- through the rollover valve into the evap system where vapors are collected in the charcoal canister to be burned later. I've never been able to get a certain diagram of the whole thing. I ordered a service manual for the car from eBay, but it won't load on my computer.

I guess on older cars, the escaping air came back out through a pipe in the fuel fill tube. Then things got complicated.

[wgriswold]

The vapor recovery systems that collect the expelled vapors during fill up at the pump handle tell me that the vapors displaced during fill up come up through the fill tube. I think that the evap system allows the venting of the tank during operation and is not designed to collect the vapors displaced during fill up.

[AKAMick]

There is something wrong with the car, the dispensing pump is not the issue, none of my XC70s exhibit such behaviour, fill them up at maximum flow with no back up or problems.

[Xfingers]

I hope nobody's lined up behind you when you're pumping gas (for 10 minutes)!
Just a thought off the top of my head as a possible bandaid until you sort the problem:
What if you filled up a portable red plastic 5-gallon gas can and then poured the gas from there into your tank? It might be a bit of a scene at the gas station but maybe it would be faster?

[Silvestris66]

I usually go to fill the car up at night 1) because no one is waiting and 2) because I can hear the air escaping up the fill tube better and can fill it as quickly as possible without cut-offs.

I have been at some pumps where I couldn't fuel the car at all because their flow rate wasn't easily controlled.

It's really frustrating that no one seems to know exactly where the air in the empty tank is supposed to go.

[Silvestris66]

OK, I had time to swing by the Volvo repair place today, and the owner said that, as far as he can tell, all the vent lines are clear. He thinks the problem is a rollover valve which he described as "a ping-pong ball in a cage." I would guess it's like the ball in wet/dry vacuum cleaners that shuts off the air if the vacuum cleaner gets knocked over.

I got the feeling from him that he doesn't want to get into trying to fix this, period.

Is there any remotely imaginable way that something like this could be un-stuck through the fill pipe?

[Sierra]

Sell it with a full tank of gas. And an As-Is transfer of Title/Written Receipt.

[v70+xc70]

Sell it with a full tank of gas. And an As-Is transfer of Title/Written Receipt.

Thats not helpful. The problem has been discussed before.

http://www.volvoxc.com/forums/showthread.php?11452-XC70-Fuel-overflow-or-block

[Sierra]

It really can be Helpful ...... It all depends on what set of shoes you are standing in - to be quite honest.

[Silvestris66]

Thats not helpful. The problem has been discussed before.

http://www.volvoxc.com/forums/showthread.php?11452-XC70-Fuel-overflow-or-block

I've been working on this problem for a while, and, as far as I can tell, there are multiple possibilities. In this case, the mechanic claims that he has pressure-checked all the vent lines and that that doesn't appear to be the problem. He thinks it's a restriction at the bottom of the fill neck -- namely, the rollover valve.

From what I just googled, it's a plastic ball that also prevents siphoning gas from the tank. I can't quite figure out what would cause it to malfunction unless it became deformed.

[hoonk]

the rollover valve, it's a plastic ball that also prevents siphoning gas from the tank.

I have worked on Volvos since 1980 and have never had to replace a roll over valve.

The "can't fill up car, gas nozzle keeps shutting off" problem has been caused in the past by one of my techs blocking off a vent line under the car to do a smoke test - then forgetting to remove the blockage. Car comes back and after removal of the "test plug" is able to be refilled normally.

[Silvestris66]

I have worked on Volvos since 1980 and have never had to replace a roll over valve.

The "can't fill up car, gas nozzle keeps shutting off" problem has been caused in the past by one of my techs blocking off a vent line under the car to do a smoke test - then forgetting to remove the blockage. Car comes back and after removal of the "test plug" is able to be refilled normally.

Well, then I guess I'll have to take it to another mechanic. This guy says that he has had one Volvo before that had a problem with this anti-siphon/rollover ball in the fuel inlet.