Emissions

[maschinenbauer]

Came back a second time. I'm going to try cleaning the EVAP purge valve solenoid this weekend.

[AstraFasta]

I cleaned the valve and the code came back a few days later. Replaced with AC Delco part (it was labeled Bosch) for $70. Three years with no issues.

http://www.saturnfans.com/forums/sho...=208132&page=2

[maschinenbauer]

I did some testing on my purge valve using some human-sourced air supply. First I tried to blow though the valve unpowered, and I could definitely pass air through it. That's not right. So the next test is applying 12V, the valve clicks open, and flow greatly improves. So it functions when powered, but doesn't seem to close fully, allowing "flow during non-purge" as the description for code P0496 would suggest. I removed the valve and shot some electrical contact cleaner through, closing both ends with fingers, and shaking up the fluid inside, then letting it sit. Repeat a couple times. Now when I try to blow through one end, the valve is noticeably airtight compared to before and won't pass anything unless I apply 12V. Fixed?







Unfortunately, the same code came back on the next drive. The valve is either still passing enough air to trigger the code despite my cleaning, or I have a vacuum leak somewhere else.

AstraFasta, your write-up mentioned a cracked boot on the vacuum line running from purge valve to intake manifold. Did your replacement valve also replace this hose with the cracked boot? I am wondering if the hose rather than the valve is my problem. Maybe today I'll try to remove the hose to inspect it for cracks.

[AstraFasta]

I cleaned the old valve also and a few chunks of activated carbon came out. I didn't test the valve in any way. The code returned promptly.

The new valve did not come with the lower hose. So the OEM hose that was a very tight fit and was a bit split is still on the car. I don't think the split is big enough to cause an issue as the valve's plastic tips are very long.

Some things I learned after the fact. Maybe you could try removing the valve:

- You can check resistance as well (10-100 ohms might be reasonable but I don't know the spec for this part). If the valve seems to work with your bench power supply this test may not be so useful.

- cleaning again when it is open (powered).

- cycle it a few dozen times with a bench power supply, reinstall.

You might try a smoke test if that doesn't work.

[maschinenbauer]

I cleared the code and continued to drive. Code came back after 100 miles or so. Cleaning seemed to help, but I'm sure there's more crud inside where I can't get to.

I came across a write-up on how to disassemble and fully clean a Volvo Bosch purge valve, which looks very similar to ours. The difficult part would be splitting the glued case without breaking it. Then once you're inside, the o-rings could be toast anyway in which case it's best to just order the new one.
https://www.matthewsvolvosite.com/fo...ic.php?t=54172

So I'm just going to buy the ACDelco 55562350 off Rockauto and be done with it. I'll report back after a few hundred miles of driving with it installed.

[maschinenbauer]

I replaced the EVAP purge valve solenoid about 350 miles ago and the code has not come back, so I think it's fixed!

[AstraFasta]

Great. That is a cheap fix in the overall scheme of things.