My sons 240 sedan was having problems so I switched cars with him to troubleshoot it. After finding oil all over the underside of the hood, the PCV and flame trap area, the dipstick, the transmission dipstick, the master cylinder, and the firewall he and I removed the intake manifold to find the top half of the breather box broken off the bottom half.

I am prepared for reassembly but wondering how to avoid a recurrence of the problem.

Before the disassembly the oil pressure gauge on my dash was showing excess oil pressure (pegging out at 5 bar) even with the box blown open (which I thought would be a relief of engine pressure??).

If it's worth anything the jiggle test was holding the metal oil cap firmly down on the filler hole and the flame trap was not clogged.

I assume the problem is excess oil pressure caused by some clog in the PCV system but after reading the faq I am certain I don't understand that system well enough to diagnose it.

Thanks to anyone willing to help

Sincerely 1 or 2 cards short of a full deck
--
Bad Blue - '86 245 with 303,000 mi. (now for parts), Good Green 1990 245 with 178,000 mi., Blacky - '91 740 wagon with 180,000 mi., Mean Green - '94 850 with 222,000