Odd noise after bike is off

I have a 22’ panigale v4s and after getting back from a ride on a hotter day I noticed that the bike was making a sound like when the fuel
Initially turns on even after the bike was off. This sound would happen every 5 seconds or so. Sounded like a glug glug for lack of better words. I had assumed the fuel was really hot and moving around or something along those lines so I added more fuel to the tank and the noise disappeared. Curious to see if this is something that is expierienced by others as well.

i bet when you opened the tank lid the noise stopped....its hot in there and it draws a vac that you can hear...

SirJAG said:

i bet when you opened the tank lid the noise stopped....its hot in there and it draws a vac that you can hear...

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Yes, when I opened the cap the tank vented a little gas like it usually does when hot. The noise still seemed to continue but it sounded like it was settling . It stopped immediately once I filled the tank with gas. Just want to make sure this is normal

It sounds like the fuel is boiling in the tank, which is pretty normal. When you added more fuel you cooled it down.

I've got the same issue. It's like vapor is building in the part of the lower tank under the seat and then bubbles forward to the main part of the tank when the vapor builds up enough pressure. I've got an video of this. Ducati replacing the tank vent under the seat. Hopefully that will solve the issue. Sounds like it should.

I'd be amazed if it did.

It’s definitely the fuel boiling. Went for about a 3 hour ride through the mountains and the noise was there again and I could see the fuel moving around in the tank. Put in room temp fuel since the bike was low and everything went back to normal. I’m assuming this is nothing to worry about. Bike runs with no issues

A dealer I spoke to on the phone recommended replacing a ball valve in the fuel cap. Not sure what you’d recommend

There is (was) a check ball in the breather assembly in the gas cap. It was removed at one point and there was a service bulletin telling dealers to remove it. I've tried it with and without the ball, no real difference.

I removed the EVAP canister and ran both the overflow and breather tank lines to a catch bottle.

I'd also add that I think the guy here who went with a racing style gas cap don't have the venting/vapor build up problems as they seem to vent straight to the atmosphere. I wouldn't use one if I parked my bike in public places for extended periods of time. The LighTech TFN212 is the correct part for 1199 and newer Ducati bikes that all use the same OEM gas cap. The LighTech is the only one I found which will fit the Ripper gas nozzle, should you like that for track days.



These nozzles are a pretty cool design in that they're self venting and will shut off when the tank is full. No hoses or funnels to mess with. Its too big for the OEM gas cap though.

I don't think the fuel is boiling. It would be pretty obvious if it was. What I'm seeing is a bubble coming from the lower tank under the seat moving forward into the upper part of the tank once every 20 secs. It only happens when you brake hard enough with enough air space to allow air to get part of the tank under the seat. The air gets trapped there if the valve under the seat isn't removing the trapped air. At least that's the best I can figure out at this time. When that valve is replaced eventually and it does it's job it should stop the issue.

Ds760 said:

I don't think the fuel is boiling. It would be pretty obvious if it was. What I'm seeing is a bubble coming from the lower tank under the seat moving forward into the upper part of the tank once every 20 secs. It only happens when you brake hard enough with enough air space to allow air to get part of the tank under the seat. The air gets trapped there if the valve under the seat isn't removing the trapped air. At least that's the best I can figure out at this time. When that valve is replaced eventually and it does it's job it should stop the issue.

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Mine is just a noise like fuel is moving every 3/4 seconds. Instantly goes away once I top off the tank with cool fuel. It also only happens on hotter days or after a long ride when the temp gets high on the bike. Doesn’t happen on cooler days

smithbuddy760 said:

Mine is just a noise like fuel is moving every 3/4 seconds. Instantly goes away once I top off the tank with cool fuel. It also only happens on hotter days or after a long ride when the temp gets high on the bike. Doesn’t happen on cooler days

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Can it be fuel vapor building up?

Something I found from another post......


It would have to get very hot before that would happen. The higher the altitude, lower the atmospheric pressure, the more likely it is to boil.
Now, that being said, fuel lines in close proximity to very hot objects, like an exhaust header, might experience some boiling but it would be very rare in a fuel injected bike. Fuel line pressures are on the order of 3 bar or 3 atmospheres which would keep the fuel from boiling. The fuel pump is in the tank and the suction side of the pump could wind up far enough below atmospheric pressure to maybe cause hot fuel to vaporize within the pump, in which case you would have a condition known as vapor lock, in that the pump would be trying to pump vapor rather than liquid fuel and it can't do that.
Proper and functioning venting of the tank is the normal cure for that. Even though fuel can vaporize at 100 F, it also has a very high latent heat of vaporization which tends to cool the fuel.
Now we come to our "friend" the charcoal canister. These can easily become blocked and prevent proper venting of the fuel tank which can prevent maintaining a pressure in the tank of 1 bar. This can cause that vapor lock issue. If you are running into issues, I recommend removal of that charcoal canister and proper venting of the tank to atmosphere. The EPA will hate this idea but your bike will love it.

Gas pressure does release when I open the cap but nothing out of the ordinary compared to my brothers v2 when it’s hot

I've got the tank open and I can see the bubble move from the back lower part of the tank to the front so I'm convinced it's vapor pressure in an air pocket pushing forward. The gas is warm and turning to vapor. Should bleed out the seat valve but isn't.

I mean the real question here is whether this is totally normal or soemthing I should work towards finding a solution for. It seems isolated to when the bike sits after running hot for a while, and goes away after being filled with gas.

If its not causing a problem its not causing a problem.

bp_SFV4 said:

If its not causing a problem its not causing a problem.

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More so I want to make sure this is standard so that nothing develops later on.

My dealer is doing a warranty claim on that pressure valve. Just waiting on the part to arrive.

Ds760 said:

My dealer is doing a warranty claim on that pressure valve. Just waiting on the part to arrive.

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Did they actually see an issue with your valve or are my going off a guess?