1995 8-Valve 940 Wagon B230FD, ~240K miles.

We've owned this car for about 6 years now and put at least 80k on it. I've kept up with the normal maintenance items, brakes, tires, shocks, filters, fuids, full tune-up but in the last few years the engine is starting to feel tired. There's also a bit of vibration in the engine lately.

In the six years and 80k miles we've owned and driven the car, I've *never* checked or adjusted the valves on this engine. The recent vibration reminds me of a pushrod B18 or B20 needing valve adjustment. So, obviously I wonder if I need to do an adjustment.

I've never done this on a B230. it looks like actually shimming the valves requires removing the timing belt... which will be difficult considering how badly the IPD tool crank holding failed me.

How does a valve adjustment affect the B230? I assume the vibrations stop, does it help at all with power?

I expect that the engine may need some rings, which could lead to a full rebuild, but don't have time or a spare car to undertake such work right now.
The weather turned cold again, and it's probably going to stay that way now...

Any thoughts?