1997 850: throws DTC P0410 between 87-90 miles of drive Topic is solved

[erikv11]

OK good to know, I was just just guessing about why there may be two different exhaust manifolds.

[misha]

Turbo and n/a manifolds?
Document shows Volvo sas system....it's the same on late 850s and s,v,c70....it's not specific to 850 only.

[erikv11]

Turbo and n/a manifolds? ...

Oh of course!

I've never had a turbo with SAS so I didn't think about it, but on a turbo car the SAS valve mounts into the downpipe (use pipe #34) not on the exhaust manifold. There is no SAS bung in a turbo exhaust manifold. For an NA the SAS valve mounts into the end of the exhaust manifold (pipe #11). I think there are even NA manifolds with the bung further down, as well.

Turbo car setup:

025.jpg (130.16 KiB) Viewed 1635 times

and this

sas_pipe.jpg (45.23 KiB) Viewed 1631 times

[abscate]

DOHC is Swedish for no SAS, or is that the airline?

The “ dual valve “ picture above is a bit confusing, but Volvo diagrams will show different versions of a system on one page, so that one gets confused.

[misha]

Turbo and n/a manifolds? ...

Oh of course!

I've never had a turbo with SAS so I didn't think about it, but on a turbo car the SAS valve mounts into the downpipe (use pipe #34) not on the exhaust manifold. There is no SAS bung in a turbo exhaust manifold. For an NA the SAS valve mounts into the end of the exhaust manifold (pipe #11). I think there are even NA manifolds with the bung further down, as well.

Turbo car setup: 025.jpg

and thissas_pipe.jpg

Case closed!

[xHeart]

Ours is fitted with SAS for naturally aspirated aka non-turbo. The air pump is situated under the battery tray, but accessible with air guide off.
It is idling closer to 1000RPM -- you can feel her anxiety.

We are in our 5th winter this year.

[misha]

N/a with automatic transmission is idling close to 1000rpm when it's in "D".
Manual a bit less.

[xHeart]

N/a with automatic transmission is idling close to 1000rpm when it's in "D".

Correct, but I'm used to it idling close to 850rpm in "P" with engine warm.

Should I just go ahead and service the valve -- hose connections for damage, repair, and replace gasket?
Here is the setup:

MVS_Sas_0078.jpg (204.36 KiB) Viewed 1389 times

[misha]

Sas valve is not serviceable.
Internal diaphragm is usually burnt over and because of that it gets stuck open.
If it's allready stuck open...air pump is on it's way out too since all condensation from exhaust manifold ends up via bad sas valve into the pump....after that on wot ends up in the air filter messing up Maf sensor.

I got 2 maf sensor failure due to this problem untill i realized where from all that water(condensation) ends up into air filter.

Sas delete is my advice ...since it's useless.

[xHeart]

Robert's DIY video

[youtube][/youtube]