1998 v70 Secondary Air Pump Internals (Pics)

[erikv11]

Remember, in the 98 models (as in other years) this particular emissions component (SAS) was only installed on some S/V/C70 cars, not on others.

[MrAl]

Hi,

Wow that's interesting. I wonder how they mitigated the faster heating of the cat then with those cars?

[erikv11]

The air pump was installed on some 850s from 96-98. There was no mitigation for the vehicles that didn't have it, they just didn't have it. The later cars have VVT (but not all of them, e.g. NA 1999 do not) which speeds up the heating of the catalytic converter, that achieves some of the same effect as the air pump.

It's an emissions gadget that, like EGR before it, was not on every vehicle and was short-lived. That is partly why I feel no remorse about doing the SAS delete (diode) procedure.

[MrAl]

Hi again,

That's very good to find out, and explains a lot.
Thanks for telling me about that.

This car is so tricky every which way i look.

[scot850]

The real problem is not the air-pump themselves but the valve that feeds air to it. On turbos it is fitted near the turbo. What happens with age is the valve sticks open and allows moisture to drain down into the pump. As there is no drain it just fills the pump up until it leaks. I drilled a small hole in the bottom of the pump casing and this allows water to drain out and not flood the pump. Having said that, I had already replaced the valve.

Neil.

[MrAl]

Hi,

Sounds like a good idea to replace the valve. I'd be a little afraid to drill a hole in that pump though, as it is quite an expensive unit.
Maybe a tiny tiny hole, but then i'd worry that it would get clogged up over time anyway.
All this tells me that there should be some dynamic test that can be performed every time the car is turned on. In the area of electronics there are so many types of sensors that there must be some kind of sensor that can be used to detect the problem.
A little funny but possible would be to install a little glass 'window' somewhere so we can see any liquid, although that might get fogged up anyway.
I'll have to give this some more thought. I suppose a hole drilled can be plugged up at some point if you change your mind. I would wonder how much the outlet pressure would be reduced.

[scot850]

If I recall it was a 1/8th" hole I drilled, but with the benefit of taking one apart, drill it on the side of the impeller which has the feed from the valve. This will limit the pressure loss. Although I did replace the valve, I did check the SAS pump periodically and it was dry. Ii never set off any codes as the loss is minimal. The balance is that a seized pump does nothing, so even a slightly compromised one is a better option. I bought a re-built unit on exchange for $130 US if I recall. It worked great and no issues.

Neil.

[MrAl]

Hi,

I am getting a new 'valve' too soon, just to see this system operate normally at least one more time, then i will probably go to the 'diode' fix that various members here have talked about which totally eliminates the need to have that barely-does-anything system up and running anyway. If you have not considered that you may wish to at some point too.
But before i knew that much about the diode fix i already bought a new pump, so i might as well see it through so i know what a working system looks like.
Funny, when i first installed the new pump, the system checked out good, and the SAS reported an "OK" in the ODB2 check. Then later it went sour again and set the check engine light again so i wonder what went wrong. The pump still runs and it still looks good so another component must have went bad now. Will be interesting to find out what it was.

[erikv11]

Hmmmm I would make sure the new pump isn't full of water, due to a bad SAS valve. scot850's fix is not an anomaly people have been doing that for years, it was SOP on the forums before the diode came into vogue.

[MrAl]

Hello,

Thanks. What does SOP mean?

I'll check it again soon. When it does run it sounds about the same as before though. I will check anyway.