Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.
ah, thought I'd check on this thread, almost a year later.
Yup, I guess it is the ABS check up thing. I kept thinking something was wrong with my car until I drove a couple other 850's and they did exactly the same noise, always at 30km/h.
Good to know there's nothing terribly wrong with it