Rollover Valve fix other than Replace Tank?

subaru
engines
gas-tanks
gasoline
lights
impreza
valves
leaks

#1

Got 2005 Subaru Imprezza Wagon from my mom. Had been in a wreck within the previous year, and after insurance repairs, check engine light kept coming on. Mom was too busy to pursue the issue, but once I had the car, I knew it would need to be fixed in order to pass the next state inspection (they won’t even attempt an inspection if the check engine light is on) .



Dealership ran the codes and said it was a large vacuum leak and found a charcoal filter hose loose in the exhaust system. Seemed simple enough but…



Right after, I went on a long road trip. Was very difficult to fill gas tank on my trip and check engine light came back on within first 24 hours. Upon return from trip, I went back to the dealership, and they said check engine light being back on was small vacuum leak due to gas cap not being tightened enough. They couldn’t explain the difficulty refueling. So, they simply reset the codes and chastised me to tighten the gas cap.



The check engine light came BACK on within a day or two once again and I was absolutely certain that it had nothing to do with the gas cap tightening. Just so happened that someone called into Car Talk with a problem refilling gas tank (pump cutting off repeatedly, just like I was experiencing). Click & Clack told the guy it was likely a busted overflow valve and an easy & inexpensive fix.



So, I go back to my dealer, exasperated, and tell them it’s not my gas cap and is likely an overflow valve and that I’m tired of coming back for the same problem (i.e. check engine light … which is the main thing I really care about for upcoming inspection).



They tell me no, no, it’s not an overflow valve but a faulty rollover valve, which cannot be replaced or repaired because it’s built into the gas tank. So, they say I need to replace the whole gas tank, which will run $1100, which I can’t afford.



So, now it’s not winter and refueling taking 10 times longer due to pump cut-offs is especially vexing in the cold and my inspection date is coming up fast. I’m hoping the dealership is either wrong about the problem or wrong about there being no other fix than to replace the gas tank. Additionally, in the meantime, I took the car in due to recall to have a =different= fuel-system valve replaced (unfortunately, no, that repair didn’t fix my problem). But the whole saga has made be very distrustful of the dealership, and they are the only dealership anywhere close to my home.



Do I really need to replace whole tank? Isn’t there SOMETHING else to try? I’d happily live without a rollover valve, can’t it just be plugged up to eliminate the vacuum leak that sets off the check engine light? Would this valve really cause the refueling issue? HELP!!!


#2

You could try to pop the valve open by running a thin wire, like a coat hangar down the fuel tank filler neck. I would loop the end so I don’t accidentally punch a hole though a rubber flex tube.

Removing the rollover valve would require the tank to be dropped to access it. It is located where the filler neck attaches to the tank itself, and not accessible with the tank in place. I would advise against removing it, as it is a simple safety feature that could save your life. Simply freeing it up and opening it is all you need to do.

As far as the small leak, a loose or damaged gas cap is only one possible problem. A small leak can happen anywhere in the evap system, from the engine vacuum source to the charcoal canister, purge valve, and gas tank itself. These can be hard to locate, and a smoke test is usually used after the gas cap is checked and eliminated as a problem.


#3

Thanks so much for the info!!
Can you please clarify whether or not you think a rollover valve issue could be the cause of the small vacuum leak code? That’s the claim of my dealership.


#4

Oh, also, do you think a rollover-valve issue would be the cause of my fueling issue where I have to fill it holding the pump lever at baby speed to avoid immediate pump cut off?


#5

I am having trouble connecting a “charcoal filter hose” and the exhaust system. Now a charcoal filter hose and the evaporative emissions system, that works.

I point this out to only make others aware you may be making unintended mistakes when you are relating the problems, symptons, repairs, and other components related too your vehicle.


#6

You need to contact your mom’s insurance company. Things which are discover during accident repairs, or AFTER accident repairs, are covered by the insurance. I think you have up to a year to make a claim. I think the EVAP system problem is a result of the accident.

It seems that no one has looked under the car at the gas tank area. You might discover something that way—a loose vacuum hose, vacuum line, or a bent something.


#7

I don’t think so. Unless there as other hidden damage that is causing a leak at the gas tank filler neck.


#8

A stuck closed or partially closed roll-over valve IS probably the cause of your slow fill problem, as I tried to explain.


#9

I have successfully used the following items to dislodge stuck roll-over valves, which are usually a cork ball in a cage…

A fiberglass bicycle flag whip…
A 3/8 plastic tube sometimes used in plumbing ice makers in refrigerators…
A light-duty plumbing snake…

The CEL can usually be reset long enough to pass a state “test” by disconnecting the battery for a few minutes…


#10

you are correct … should have been “emmissions system” rather than “exhaust system”. sorry for confusion.


#11

Thanks again everyone! I have printed suggestions out and will have hubby try to pop the valve as you suggest.


#12

As you might imagine, while doing the baby-speed on the gas pump, it’s actually a lot easier to overflow the tank. I did this once and did notice that the gas was not only coming out of the place where you put the pump to fill the tank but also seemed to be coming out from behind the metal body of the car to the left of where one fills up (i.e. seemed to be running down the =inside= of the body of the car to spill out right next to the rear tire). is that usual … i.e. some sort of overflow exit point? or could that be the actual vacuum leak point?


#13

For caddyman would I be sending the object down the fuel line or the vent line to dislodge the valve?


#14

This would depend on what you wish to accomplish. The OP’s car has a broken and leaking fuel tank over-fill control/roll-over valve causing a check engine light. The advice to shove a fiberglass pole down the fuel fill tube may cause further damage. Are you the OP with a new screen name?


#15

If worst comes to worst and you or your mechanic have to replace the tank, you will save money by not involving the dealer. Around here we have used parts dealers that bring up rust free tanks, doors etc. from the South by the truck load.


#16

Isn’t a “rollover valve” just a glorified ping-pong ball? Seems any object capable of pushing down on it would work; even a wack on the filler neck with a mallet might.