1999 V70na P0455 Evaporative Emission Gross leak error

paredown · Post by **paredown** » 22 Apr 2014, 05:59

Well, the rest of the work has made the car a nice driving machine--did a 500 mile up and back to Boston, and it ran flawlessly--edged up over 24 mpg av. according to the trip computer.

However, after the second long shakedown drive I got a CEL that I confirmed later as P0455 code. I cleared it once, but it reappeared on the return leg of the Boston trip.

Read this thread that said it is often the gas cap--or at least that is a good place to start:
https://www.matthewsvolvosite.com/forums ... 8&start=28

Gas cap was seated though AFAIK--and after I cleared the code, I made certain that it was.

I will start with the small vacuum hoses that route from intake manifold to fan shroud--I trimmed the ends of the old hoses after I did the PCV but was going to come back to replace them anyways.

Besides that, should a new gas cap be the next step? (I'm pretty sure that it is original to the car @158,000 miles)

Post by **mtd240** » 22 Apr 2014, 06:33

Be sure to search before posting a new thread, using:

search term site:matthewsvolvosite.com

Here are a couple relevant threads:

P0455 Evaporative Emission Control System Leak Detected
99 V70R EVAP/engine surge/P0455 code

On my 1998 XC, the P0455 was thrown by a busted up roll over valve hose (PN 3501350) in the rear of the car, behind the gas tank. On my car, the carbon canister is rectangular shaped, right in front of the driver side front wheel. I started by checking all hoses connected to that, then moved to cleaning all the EVAP valves/filters in the engine bay. Someone recently posted how to make a DIY smoke tester - that would help!

paredown · Post by **paredown** » 22 Apr 2014, 07:03

I already did search and posted a link to one of the two threads that you posted.

Neither of those threads are conclusive or offer much in the way of procedure, and in the one I linked, someone said 'Start with the gas cap"--and I was asking the simple question as to whether other people thought that was the place to start.

In fact, your summary comment at the end offered more information than either thread!

A question--how did you clean the valves/filters in the engine bay? (since this was where I said I was going to start by replacing the small hoses).

Post by **mtd240** » 22 Apr 2014, 07:18

paredown wrote: In fact, your summary comment at the end offered more information than either thread!

A question--how did you clean the valves/filters in the engine bay? (since this was where I said I was going to start by replacing the small hoses).

Good stuff. I just used Carb/TB Cleaner. Nothing fancy. I was happy I cleaned them (even though they didn't fix the CEL) - they were filthy. The carb cleaner came out completely black for a while.

Post by **rmmagow** » 22 Apr 2014, 10:35

On my 98 V70 Turbo the canister is located sort of in back of the driver's side headlight. From underneath I reached up to the top and found some big hose was crumbling. I did a bit of a hack job to fix it and my P0455 went away (nearly a year now). I wanna say "j hose" but I don't know for sure if it's called a j-hose when the canister is located in front. Removing the side marker light let me actually lay eyes on the thing.

paredown · Post by **paredown** » 23 Apr 2014, 14:45

Still have not got back to this, since we have a house full of guests, but I did find some more information.

I found this thread on Matthew's that has a full description of the evap/fuel system:
https://www.matthewsvolvosite.com/forums ... =1&t=57952

And I found this thread on Bob's the Oil Guy that seems very systematic for troubleshooting:
http://www.bobistheoilguy.com/forums/ub ... er=2305162

Unfortunately, the new gas cap sold to me by the dealer is for the newer V70s and sticks out a little too far, & I still don't know if it is sealing properly or not. It does seem to be the case that I do not get the sound of releasing pressure when I fill the tank, so I think I will be checking the hoses for the roll over mech (close to the fuel filter).

I also think that I answered my own question about 'why now'--since the purge cycle only runs after some time of continuous running, it explains why this code can be cleared and will reappear.

Post by **abscate** » 23 Apr 2014, 16:32

The EVAP cycle is one of the more complex ones and typically takes 100 miles of driving to complete.

The gas tank has to be above a certain level, the AC can't be on all the time, etc etc.

There is a detailed description of it posted in one of the threads - I will find and link.

paredown · Post by **paredown** » 24 Apr 2014, 12:12

Well, if you are patient, sometimes you are rewarded.

On mine (Code "A" from the VIN), the evaporative canister is located in the vicinity of the fuel filter, and of course everything is covered in crud. Some cleaning with a small wire brush and no joy, but on a second pass I spotted multiple cracks on the J hose where it enters the charcoal canister. PITA to reach, but I will replace that first, since everything else looks OK on a visual inspection.

For others who are interested, the correct part for mine is 9443308, or #10 on the diagram:

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paredown · Post by **paredown** » 30 May 2014, 11:03

What with real life intruding I have not had much time to get back to this.

Ordered the 'J' hose and replaced, but while I was under the car, I noticed that the long straight hose (#11 on diagram) also had splitting and cracking. So then it was another week before I had it in hand, and another week or so before I could replace it.

This time, I jacked up the car, set a jackstand and removed the back wheel for more access. I also removed the fuel filter, and actually replacing the hose was not too awful, although I ordered the wrong size pinch clamps and had to use screw-style ones from the local hardware store.

Unfortunately, the code has not cleared on its own, so now I need to figure out next steps. (I've cleared it with a reader, but my suspicion is that it will come back...)

Next may be the gas cap, since it seems that the tank system is not holding any pressure...

Post by **rmmagow** » 30 May 2014, 12:01

On my V70, which just started popping the P0455 code after months of being off, I never got a woosh opening the gas cap. I'm getting the code again and will be testing the purge valve, the one at the radiator shroud. My gas cap is maybe 2 years old and right from the dealer. The P0455 is a pita.