Volkswagen Passat Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
120 Posts
Discussion Starter #1 (Edited)
Hey guys,

So the 02 Passat 4 motion I picked up came with the CEL on and these codes.

Try as I could to hear the SAI pump running on cold start, I could not. Even when turning off the motor, giving it a chance to begin blowing after starting, I would not hear the vacuum sound winding down.

I checked the fuse and tested the relay, they were all good. Plastic hoses were good. Assumed the pump was dead.

Yesterday spent about 2 hours at the pick & pull with some wires and a drill battery to test multiple pumps, ended up finding one and bought it ($35).
Today I installed it, cleared the code, and started the car. No CEL came back on. Went under the car and confirmed that the pump was blowing and then as I let it idle a few minutes it eventually powered down.

Here's where things get stupid. With the first pump out of the car I hooked it up directly to the battery and it turned on just fine...

For my loss-wasted time.

Can anyone explain what may have been going on here. I should have just cleared the code to begin with before getting into all this and next time I'll remember to test the pump on the car before removal. Biggest question is: Why would I not hear the vacuum sound continuing when shutting off the car?
 

·
Registered
Joined
·
120 Posts
Discussion Starter #3
P0491 - Ross-Tech Wiki

See if anything comes back after a few drive cycles.
Thanks for the info! So unfortunately, the code came back after about 50 miles of driving. I poked around a bit this morning and I discovered that the thin plastic line within the vacuum hose that runs from the passenger's side combi valve to the driver's side valve, broke at the plastic where it inserts into the driver's side hose (see photo-plastic tube on left). Could this be my issue? My understanding is any leaks between this connection could throw the code for both banks as the one valve tries to compensate the air flow. Would a regular piece of hose between these two potentially remedy this? I've never seen one of these types of lines with a smaller plastic tube within the hose.


IMG_20170423_112003568.jpg
 

·
Registered
Joined
·
1,921 Posts
Dig out the broken piece from the rubber hose and fit it all back together if it will reach without pulling on it. If it won't reach you can replace the plastic tube with a length that will.

Not sure if that would cure the code but any breaks in the lines need to be fixed.
 

·
Registered
Joined
·
120 Posts
Discussion Starter #5
Dig out the broken piece from the rubber hose and fit it all back together if it will reach without pulling on it. If it won't reach you can replace the plastic tube with a length that will.

Not sure if that would cure the code but any breaks in the lines need to be fixed.
That's the thing, I don't think it'll reach. If I go to a local parts store are they going to have the 3.5 mm hose? I could just replace that side for now until I can pick up silicone hose and replace everything.

EDIT: Well, I managed to stretch it a bit and make it work. Hopefully it's connected well enough. May try to wrap a bit of electrical tape around the connection just for now.
 

·
Registered
Joined
·
120 Posts
Discussion Starter #7
So, the CEL cam back on, but it's a new code: p0441, for what I've read is most likely the purge valve, but could also be from not tightening the gas cap?

What I'm wondering is could the incorrect flow be stemming from the fact that there is not enough air flowing through the hose with the plastic bits that broke off inside? Is it possible I didn't get all the plastic out before inserting the tube? Would these be connected?
 

·
Registered
Joined
·
120 Posts
Discussion Starter #9
I was able to get the same piece off a Passat the local scrap yard, also grabbed a purge valve just in case (though I hear mine clicking softly and I have not had a chance to spray carb cleaner in yet). Tightened down on the gas cap and put electrical tape around the plastic tube for now and the code has not returned after 80 miles so hopefully I pass 100 without issues.
 
1 - 9 of 9 Posts
Top