P0455 purge valve vacuum
10-03-2021, 04:59 PM
#1
Junior Member
Thread Starter
P0455 purge valve vacuum
Hi all, I've been chasing a P0455 on my 2011 E350 Wagon.
A while back I had a CEL indicating the EVAP purge valve was bad (engine drivers side, #2124702493). I tested it with a vacuum pump and it was indeed stuck open.
After installing the new valve the old codes cleared but I have had a P0455.
Using my Mitivac hand pump, I'm unable to maintain a vacuum on the fuel tank side of the purge valve. I'm concerned my replacement valve is faulty, and won't allow a vacuum for the EVAP test?
Shouldn't the purge valve hold vacuum on the outlet to the fuel tank?
Thanks in advance for all the help!
A while back I had a CEL indicating the EVAP purge valve was bad (engine drivers side, #2124702493). I tested it with a vacuum pump and it was indeed stuck open.
After installing the new valve the old codes cleared but I have had a P0455.
Using my Mitivac hand pump, I'm unable to maintain a vacuum on the fuel tank side of the purge valve. I'm concerned my replacement valve is faulty, and won't allow a vacuum for the EVAP test?
Shouldn't the purge valve hold vacuum on the outlet to the fuel tank?
Thanks in advance for all the help!
10-03-2021, 06:46 PM
#2
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Join Date: Apr 2019
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MY'14 W212 M276 3.5NA @60kMi
sealed system...
The ECU monitors the ability of your tank assembly to hold gas fumes under a sealed vacuum.
So yes both vent and purge valves need to pass the vacuum test.
It's rare that new parts are bad straight out of the box unless they are from questionable sources. You've replaced your PURGE... now checkout your VENT valve.
So yes both vent and purge valves need to pass the vacuum test.
It's rare that new parts are bad straight out of the box unless they are from questionable sources. You've replaced your PURGE... now checkout your VENT valve.
10-03-2021, 06:58 PM
#3
Junior Member
Thread Starter
I agree, it's pretty rare to have a bad part.
But if I put my vacuum pump directly onto the new purge valve connection toward the fuel tank, shouldn't it hold vacuum? and not leak down within 30 sec.?
(If I put my vacuum pump onto the old valve, (and hold my finger over the connection toward the intake manifold, since it's failed stuck open) - it holds a solid vacuum. The new valve does not hold vacuum even with my finger over the intake connection....)
If that info helps you or anyone with advice. Thanks!!
But if I put my vacuum pump directly onto the new purge valve connection toward the fuel tank, shouldn't it hold vacuum? and not leak down within 30 sec.?
(If I put my vacuum pump onto the old valve, (and hold my finger over the connection toward the intake manifold, since it's failed stuck open) - it holds a solid vacuum. The new valve does not hold vacuum even with my finger over the intake connection....)
If that info helps you or anyone with advice. Thanks!!
11-21-2021, 06:35 PM
#4
Junior Member
Thread Starter
Just to follow-up on my 2011 E350 wagon 4-matic, 146,000 miles -
It turned out that I indeed had a bad part, the new replacement valve failed to hold vacuum on the fuel tank side.
In all my testing I squirted "carb cleaner" and WD-40 into my original purge valve. Then I applied 12v to it multiple times and it eventually came unstuck. At that point my Mityvac hand-pump began to give results I expected - that the valve should hold vacuum on the fuel tank side as well as the engine intake manifold side.
So I re-installed, cleared the codes, and I'm >1000 miles on the original valve with no CEL or other issues.
Kudos to Dorman for having a lifetime warranty on the part, and kudos to Rockauto for making the replacement process unbelievably easy.
So I have a new spare purge valve ready for action.
I did test out the rear vent valve - it seemed okay but the filter material was coming apart so I replaced it also.
I would recommend replacing both valves at the same time just for good care.
Purge valve
#2124702493
DORMAN 911855
Vapor Canister vent shutoff valve
A 000 474 29 30
DORMAN 911-733
I hope this helps someone!
It turned out that I indeed had a bad part, the new replacement valve failed to hold vacuum on the fuel tank side.
In all my testing I squirted "carb cleaner" and WD-40 into my original purge valve. Then I applied 12v to it multiple times and it eventually came unstuck. At that point my Mityvac hand-pump began to give results I expected - that the valve should hold vacuum on the fuel tank side as well as the engine intake manifold side.
So I re-installed, cleared the codes, and I'm >1000 miles on the original valve with no CEL or other issues.
Kudos to Dorman for having a lifetime warranty on the part, and kudos to Rockauto for making the replacement process unbelievably easy.
So I have a new spare purge valve ready for action.I did test out the rear vent valve - it seemed okay but the filter material was coming apart so I replaced it also.
I would recommend replacing both valves at the same time just for good care.
Purge valve
#2124702493
DORMAN 911855
Vapor Canister vent shutoff valve
A 000 474 29 30
DORMAN 911-733
I hope this helps someone!
