RPM gauge accurate up to 6000-7000 then flutters

[secondarybob]

Hi all,
On my 1983 550es, the RPM gauge seems accurate up until about 6000-7000 or so, and then as I increase RPM it flutters and never reads higher than 7000 RPM or so even as the engine is clearly above that RPM and not fluttering as the gauge needle is. I've not been able to find a similar report on the forums and am wondering if this is likely a problem on the sensor end or the display gauge?

Thank you!

[Burque73]

The gauge probably needs some lube on the gears inside it. Do a search on lubricating tachometer or something along those lines. Both my speedo and tachometer get wonky when they need lube.

[secondarybob]

Thanks! I’ll give that a shot