orientation of SAI change over valve

[Paul Ri-Chard]

ECL on: SAI codes: P0410 and P1411. Investigation shows failed change-over valve (stuck shut).
My failed valve was oriented upside down according to the schematics that show the vacuum source pointed down.
Does it matter ?
How mine was: vacuum source up:


Matching the schematic:

The schematic, vacuum source down.

[Gelbster]

You have it the correct way around to ensure the valve operates properly
FYI there is a very similar part for Mercedes which is much cheaper in a previous Thread.
Part number is 000 140 77 60, $35 on Fleabay or the Genuine Mercedes part from RND for $44
http://store.rndeuroparts.com/catalog/SSF/catalog.aspx?SearchedText=0001407760

[particlewave]

The correct OEM orientation is with the vacuum chamber down, as in the diagram. It will work just fine in any orientation, though. You just need to make sure that it will fit and that the vacuum line will reach without obstruction.

[Boxstard]

I just did the same job over the past weekend!

I oriented the vacuum chamber up, vacuum line was long enough to the solenoid, and works just fine. In retrospect, downward orientation would make it easier to access the hose clamp through the intake manifold runners to fine-tune the hose angle to the pump, without the little vacuum chamber nipple getting in the way.

In my case, elastomer diaphragms in the change over valve as well as the check valve were gooey and stuck shut, throwing the check engine light every a few days. I have not annoyed with the light for two days, hope it stays this way for months to come!

[particlewave]

Mine was rusted badly on the vacuum side, preventing the valve from opening.
It's been 4 months since I fixed it and it's still working fine...no codes.

[Paul Ri-Chard]

"I just did the same job over the weekend."

Ugh!

This was my third time in the last month.
First it was a visible broken line and a vaulty ICV (P0506). Replaced vacuum line and ICV and drove for 200 miles with clear codes and no CEL .
Then I replaced the electric change over valve, because it failed 2 weeks later.
Drove another 250 miles and then P0410 and P1411 returned.

Oh joy!

Went to the Pelican and ordered new vacuum chamber reservior, new change over valve, new check valves and new rubber hose connections. Luckily the air pump is working strong with no dying noises.

Word of advice:
You can be cheap, but what is your time worth ? Spend an extra hour or two checking all the components before you put it back together, or just replace them all at once. It's hot in that engine bay. Those plastic and rubber parts have had nearly 20 years to vulcanize.


The good news:
I've become very fast after three visits to the SAI system.