Home Technical Discussions Volkswagen EuroVan: 1992-2003 (T4)

Volkswagen EuroVan: 1992-2003 (T4) Checking EGR valve


Permlink Replies: 3 - Pages: 1
Last Post: Mar 21, 2017 2:26 AM Last Post By: vanalemon
vanalemon

Posts: 83
Registered: 03/03/04
Checking EGR valve
Posted: Mar 15, 2016 1:43 AM
  Click to reply to this thread Reply
hi,
I checked the EGR valve per Bentley's manual. (1997 camper)
I do observe the stark change of idle when applying vacuum to the hose.
However, the hose/valve does not "HOLD VACUUM". It "fills" in about 1 second.
Is this expected?
Or am I looking at a cracked diaphragm? (just changed the hose, nothing changed, so not likely to be the hose)

Thanks for your input,
Claudio
vanalemon

Posts: 83
Registered: 03/03/04
Re: Checking EGR valve
Posted: Jun 13, 2016 1:53 AM   in response to: vanalemon in response to: vanalemon
  Click to reply to this thread Reply
Hi All,
so, I ended up changing the EGR valve. The new one does hold vacuum, so that is the answer to the original post.
It is not hard to swap the valve, but it is a fairly expensive part, I think I found it for about $350 after some searching. (www.RockAuto.com)
The CEL stayed nicely off for a couple of weeks after the change.

Then it came back again.
I suspect now the N18 valve might be at fault.
I tried applying 12V to the coil (engine off) hoping to hear a clunk. No sounds.
The coil reads about 31ohms.
After reading the posting at
http://forums.tdiclub.com/showthread.php?t=375711
(linked to from here: http://forums.tdiclub.com/showthread.php?t=372686)
I am not sure I should hear any sounds unless there is vacuum applied, e.g. engine running....
will probably do some more testing...

Just an update,
Claudio

Edited by: vanalemon on Jun 13, 2016 1:54 AM
vanalemon

Posts: 83
Registered: 03/03/04
Re: Checking EGR valve
Posted: Jun 26, 2016 7:12 PM   in response to: vanalemon in response to: vanalemon
  Click to reply to this thread Reply
Update.
I connected a vacuum gauge between the EGR valve and the N18 valve.
It red zero vacuum both idling and revving the engine, even after warming it fully.
That would indicate a stuck-closed N18 or lack of vacuum at the vacuum inlet (well, where the air exits the N18 to go into the engine vacuum :-) ).
Vacuum at the inlet of the valve was about 8(Hgmm?) on my gauge.
I tried tapping the side of the solenoid with the screwdriver handle (old trick with stuck solenoids) and it started chattering/clicking! Then it stopped, then it did it some more...
I still did not observe any vacuum at the EGR.
Then I sprayed some carb cleaner and later some wd40 in the N18 inlets...
probably not a great idea... could affect rubber?
on further tests, It now stopped clicking and it appears stuck open:
I read about 6 (Hgmm) of vacuum at the EGR and it idles very poorly.
Tried tapping some more, tried disconnecting the solenoid electric connector, but it appears stuck open.

At this point I pulled out the N18, placed the airfilter directly onto the main vacuum line, and will look to buy new (or possibly repair/unstuck it?).
Engine light is ON: code 1440, likely because the ECU reads an open circuit in place of the solenoid.

more in a month...
Claudio
vanalemon

Posts: 83
Registered: 03/03/04
Re: Checking EGR valve
Posted: Mar 21, 2017 2:26 AM   in response to: vanalemon in response to: vanalemon
  Click to reply to this thread Reply
Forgot to update the post (who knows, maybe in 10 years it will be useful to someone :-) ).
I changed the N18 and things went back to normal.

Point your RSS reader here for a feed of the latest messages in all forums

Popular Discussions:
No popular dicussions.