Looking for the Cure for P0455, Trouble Code

Post by **jmmxc** » 25 Nov 2010, 13:07

Happy Thanksgiving to all of you Volvo owners and drivers.
I am trying to solve a problem before my next emission inspection for next month.
I have been getting P0455 (Emission, detected Large Leak) for a few weeks now.
I had replaced the Gas Cap and the small (frayed and aging) hose that connects the Purge Valve Unit (attached to the rad) to a nipple on the intake manifold. Unfortunately the problem still persists. After resetting the code it comes back 2 or 3 days later.

Does any one have experience solving this problem?
Please send me some comments at your leisure.

Thanks,
jmmxc
1996 Volvo 850 GLT
(130K miles +)

Post by **JRL** » 25 Nov 2010, 13:50

Gas cap
Purge valve itself
Leak in a vacuum line
if all have been replaced you need to "smoke" the system to find the leak

Post by **jmmxc** » 25 Nov 2010, 14:23

OK.
I am ordering a Purge valve at FCGroton as my next step.
Can you describe the smoke test itself a little bit?
Is it something that can only be performed at a repair shop?

thanks,
jmmxc

Post by **JRL** » 25 Nov 2010, 15:53

If you don't own a smoke machine, yep

Post by **thecheat** » 25 Nov 2010, 19:14

Look in the repair database here for my procedure on testing and repairing the purge valve. Although technically it isn't necessary since you've already ordered one.

The smoke test just pumps smoke into your intake and wherever you have a leak it streams out. Similar to how water would leak out of a garden hose if there was a pin hole. Machines are like $500 and up.

Post by **jmmxc** » 25 Nov 2010, 21:07

Look in the repair database here for my procedure on testing and repairing the purge valve...

Thanks to all for your inputs.
I will check the database regardless...It is always good to know how things work and how to repair them whenever possible.
Will keep in touch and will post after the purge valve is received.

Thanks again.
jmmxc

Post by **jreed** » 26 Nov 2010, 05:08

I had the P0455 about 18 months ago and I replaced the gas cap to no avail. I checked each and every rubber hose and finally found the two broken ones that were connected to the roll-over valve near the fuel filter under the gas fill pipe. I replaced those, and problem solved.

Post by **jmmxc** » 26 Nov 2010, 08:38

I had the P0455 about 18 months ago and I replaced the gas cap to no avail. I checked each and every rubber hose and finally found the two broken ones that were connected to the roll-over valve near the fuel filter under the gas fill pipe. I replaced those, and problem solved.

Ah !!! Good you mentioned that. I was reading about the EVAP system, in a VADIS document on this site. As far as this DTC is concerned, there is very little mentioned about the Canister Valve (somewhere under the fender, driver side) and the Roll-Over valve (near the gas tank) as part of the diagnostics. Is it because they (statistically) tend to fail less?

Too bad it is raining now... I wa going to check under the car, I will have to wait for the weather to dry out.
Key you posted.
Thanks,
jmmxc.

Post by **erikv11** » 26 Nov 2010, 09:18

Actually, you have identified what are by far the most common locations for failure in the vacuum lines:
(1) the "J tube" on top of the canister
(2) the lines back at the rollover valve near the fuel filter

Post by **xHeart** » 23 Aug 2012, 14:26

jreed wrote:I had the P0455 about 18 months ago and I replaced the gas cap to no avail. I checked each and every rubber hose and finally found the two broken ones that were connected to the roll-over valve near the fuel filter under the gas fill pipe. I replaced those, and problem solved.

I have a re-appearance of P0455, could you give more detail, perhaps a photo or two? Has it appeared since? PN?