Just wanted to share some info about this;

I had a AMM failure (Air Mass Meter) when I bought my 960 last fall.
Got the tip from you guys that it could be due to a bad thermostat in the air box housing that controls the flow of warm/cold air to the engine.

Well, the volvo part (9142616) (it is not listed in volvos tech cataloges, good to know if you want to buy one) is placed just below the air filter.

I took some pictures to compare the new and old one;

This first picture is when the thermostat is cold (around 0 celcius).
It puts out its rod 7-8mm.



When warm, it only goes out to 11-12mm. Not a huge difference.


As comparison, New vs. Old. Both cold. Quite a difference.



When I was informed about the problem I disconnected the hot air duct from the exhaust, until I had the new replacement. Just to be sure. AMMs ain't cheap.
After replacement the engine feels more powerful, even after long runs.

So, check it out. It costs maybe 20$ and can save you the trouble of buying a new AMM for lots of $$$.

Just a thought..