EVAP 0455 / Rollover Valve question
12-02-2016, 10:30 AM
#1
CF Veteran
Thread Starter
EVAP 0455 / Rollover Valve question
So the code is 0455. Large Leak detected. Checked and replaced sections of the 1/4" plastic line, that wasn't it.
So when I manually apply vacuum to the line, I hear a whooshing sound from up top the tank at the rollover valve.
Since the valve is normally open anyway to vent vapors, is this the normal sound, or is it the source of the leak? Other suspects are the cap, replaced not long ago, and the fuel vent pipe that doesn't have a hose clamp at the tank.
Replies appreciated.
So when I manually apply vacuum to the line, I hear a whooshing sound from up top the tank at the rollover valve.
Since the valve is normally open anyway to vent vapors, is this the normal sound, or is it the source of the leak? Other suspects are the cap, replaced not long ago, and the fuel vent pipe that doesn't have a hose clamp at the tank.
Replies appreciated.
Last edited by 97grand4.0; 12-02-2016 at 11:45 PM.
12-03-2016, 09:24 AM
#4
CF Veteran
Thread Starter
Thanks, I had that coming.
Well I did revise my new line back to the tank, had wrong diameter line I tried to patch in with tire bead sealer and twisted wire around it. Reset the code, and so far so good not even a pending code after 2 days so we shall see. Tested the purge valve off car and it was fine. Vent valve looks to be the next suspect if the code returns.
Well I did revise my new line back to the tank, had wrong diameter line I tried to patch in with tire bead sealer and twisted wire around it. Reset the code, and so far so good not even a pending code after 2 days so we shall see. Tested the purge valve off car and it was fine. Vent valve looks to be the next suspect if the code returns.
Last edited by 97grand4.0; 12-03-2016 at 09:26 AM.
12-09-2016, 08:22 AM
#5
CF Veteran
Thread Starter
Allright, well no luck yet still PO455. So yesterday I had some time and pulled it into the shop for the morning. Tightened the clamps on the gas neck and tank vent, and went to work under the hood. On mine the evap can is under the front bumper, I can see the connections to the top and that is as close as I got. They 'looked' ok. Then on to the purge valve, vacuum lines, and the little tiny one way valve. All the connections are pretty neatly diagramed on a sticker by the radiator.
Replaced as many of the connections on the purge valve as I could (after removing the air cleaner assy). Several were suspect. The little tiny one way valve on the front vacuum line to the manifold (there are 2 vacuum connections to the manifold for the system) came apart in my hand. Ended up patching it all back together and sealing the connections with some silicone.
I cleared the code and ..I must have had a bear of a leak either before or after the system, because now it runs great, idles smooth, sharp throttle response, and hits the high rpms with seemingly a lot less effort. All this with the codes just cleared, monitors not run, and the fuel trims on the factory map. So vacuum was leaking somewhere in the 10 or so connections I refreshed. Whether this clears up the code or not remains to be seen but if not I think the next step is to drop the tank, check the fuel pump assy gasket and replace the roll over valve.
Takeaway, those tiny little vac hoses mean a lot.
Replaced as many of the connections on the purge valve as I could (after removing the air cleaner assy). Several were suspect. The little tiny one way valve on the front vacuum line to the manifold (there are 2 vacuum connections to the manifold for the system) came apart in my hand. Ended up patching it all back together and sealing the connections with some silicone.
I cleared the code and ..I must have had a bear of a leak either before or after the system, because now it runs great, idles smooth, sharp throttle response, and hits the high rpms with seemingly a lot less effort. All this with the codes just cleared, monitors not run, and the fuel trims on the factory map. So vacuum was leaking somewhere in the 10 or so connections I refreshed. Whether this clears up the code or not remains to be seen but if not I think the next step is to drop the tank, check the fuel pump assy gasket and replace the roll over valve.
Takeaway, those tiny little vac hoses mean a lot.
12-17-2016, 09:00 AM
#6
CF Veteran
Thread Starter
A week later everything looks and runs fine. No more PO455. Was the little lines under the hood, and the little one way valve in the line right off the front of the intake. That little valve crumbled in my hand.
01-11-2017, 07:03 AM
#7
CF Veteran
Thread Starter
OK so that wasn't it. Code came back after I posted last. I then swapped out the STANT gas cap I had put on it for a used factory cap with 165k on it. Been fine ever since.