98 v70 NA P0455 - my most loyal friend

[98v70dad]

I am thinking about "pressure test" instead of "smoke test" (I don't have a smoke machine).
- Basically disconnect the vacuum tubing at the purge valve.
- Connect air hose with appropriate adapter so it fits in the hose.
- Pressurize the fuel system to 5 psi or so and listen for "hissing noise".

Just a thought, too cold now (-20C in Nebraska). Will wait until I get warmer weather to do this pressure testing and report back.
Ideally this should be done inside a garage with everything turned off (no music, radio etc.) and I need to clean my ear wax beforehand so I can hear the faint hissing noise...lol.

28 F in Atlanta today. Its a beautiful day and I didn't have to go to work, but I don't really feel like working on the car. My car seems to have the code more often in the cold. If you think about it everything shrinks in the cold. I think your idea would work better if it was at least a little cold when you try it. I'm from the midwest and I gotta agree that mid January up there is not conducive to working on a car outside or even in the garage.

[98v70dad]

So today I buttoned up the access panel to the tapered hose on top the fuel tank and when I was done I messed around with the purge valve for few minutes. I took it off and cleaned the electrical contacts. After it was dry I put a vacuum on it on the vacuum side and it leaked. I shot a blast of throttle body cleaer in both sides and repeated the test. This time it held a vacuum.

Then I measured the resistance across the two leads. It is supposed to be 20 Ohms (read that in one of the many PCV system posts). Mine measured 30 Ohms on one scale and 27 Ohms on another scale (both pretty far off), so maybe the part is bad. I bought this part at the dealership and it is labeled BOSCH but in tiny letters I found "Made in China". So the chinese garbage has made it to the dealership level.

I remember that CN90 got a chinese bosch purge valve that lasted only a few months (mine has lasted a few months) so I now have my biggest current suspect in my continuing effort to eliminate the P0455 code. I don't know the test procedure for the purge valve and I didn't want to risk frying it but that fact that it seems to leak wouldn't show up on a simple "does the solenoid actuate" test.

Thoughts?

[scot850]

If in doubt of it's ability to do the job return it to the dealer and ask for another! Not sure what the warranty period is on self fitted parts now as the keep changing it. If they sell and fit the part it is now 2 years in North America. I think it may be a year, but don't quote me on it! I'd still be complaining to Volvo and see what they say.

Neil.

[98v70dad]

If in doubt of it's ability to do the job return it to the dealer and ask for another! Not sure what the warranty period is on self fitted parts now as the keep changing it. If they sell and fit the part it is now 2 years in North America. I think it may be a year, but don't quote me on it! I'd still be complaining to Volvo and see what they say.

Neil.

I thought of taking it back. I didn't save the receipt but they keep a record. I'd rather have a good part, though, and pay for it. I have never had good luck with anything made in China (especially electrical) other than basic tools at Harbor Freight.

I dont know that this part is bad but if it is I have invested at least 10 hours of my time chasing leaks that may not exist. Almost everything in the EVAP system is new now which is a good thing. I'm still planning to smoke test it. I need to make a smoker box.

[theWIFES_S70]

Hey man, sorry to hear about that Chinese Valve... Here's a link to small DIY Vacuum leak tester... I'm gonna make one of these when it gets warmer!

[98v70dad]

Hey man, sorry to hear about that Chinese Valve... Here's a link to small DIY Vacuum leak tester... I'm gonna make one of these when it gets warmer!

That's a good video thanks. I like his rig in theory but the tire compressor is capable of filling tires to probably up to 70 psi. I wouldn't want an unregulated air pressure source attached to my car. The high pressure capability may not matter the way he used it for systems open to the atmosphere since smoke is coming out of the air intake in the front (open to the atmospere - no way for pressure to build up). But the PCV system in the back by the gas tank is a closed loop. That air pump could easily blow up a gas tank like a balloon.

I'm thinking something more like an aquarium air pump to supply a little push to the smoke or a little airbrush compressor with a regulator that is accurate in the low pressure range..,,, I wouldn't want more than a few psi pressure on the system.

[98v70dad]

I think you talked about all those issues in that EVAP thread.
You just need to spend more time and read through those threads.

My experience shows me that:
- Large leak is usually: the EVAP hose above gas tank.
Rarely it is gas cap seal.

- My P0440 code is from EVAP Valve. I used Bosch (made in China) but failed within 2.5 years.
I just switched to Pierburgh Valve, so far so good:
https://www.matthewsvolvosite.com/forums ... =1&t=54546

I'm not about to knee jerk and replace my purge valve just yet but I took it off today and put a vacuum on it and it leaked...not a lot but a valve a few months old shouldn't leak at all. I just sucked on it and it had a noticeable small leak. A bigger vacuum may cause a bigger leak. That was a pretty low tech test but it got me thinking about the Pierburg valve you mentioned. The ones I've found don't claim to fit my car. Of course since the shape is different it wont fit in the holder but I would think if the electrical connection fits the rest would be OK since its just a solenoid. Do you remember how you found the correct pierburg p/n since you substituted and that part wasn't originally specified for your car?

[cn90]

My Bosch "made in China" Purge Valve lasted about 2.5 years. I now have the Pierburgh Valve (made in Germany).
It is a soccer match between the Chinese and Germans, let's see who wins.

[98v70dad]

My Bosch "made in China" Purge Valve lasted about 2.5 years. I now have the Pierburgh Valve (made in Germany).
It is a soccer match between the Chinese and Germans, let's see who wins.

Last night I was looking at your post looking for a part number and noticed that I remembered it wrong. I figured that you might correct me next time I heard from you. I'm sorry I misquoted you. 2.5 years isn't too good either. How did you find a pierburg part number that works? I spent a good bit of time looking and don't find anything that that claims to cross part numbers. My original part number was 9135444. I found Pierburg P/N 722517060 that says it fits my vehicle if the old part was 8627005. It may be that it won't fit in the mount (square peg in a round hole) but would still work....don't know

Do you have any thoughts on finding a compatible Pierburg part for my car? Thanks.

[scot850]

Have you checked with Volvo if your part number has been superseded? Volvo are constantly consolidating part #'s for the older cars, so perhaps your part number is now the 8627005 part #?

Neil.