oil pressure?
 

my 190 88 2.3s oil pressure reads high even at cold start in the morning and 2cm difference when hot. Is this norm/ If not what can be done. I had the oil changed 700ml ago.

Sounds normal
 

Cold oil is more viscous and will produce a higher pressure due to flow resistance.
Normal oil pressure at idle when hot is in the lower 1/3 to 1/2 of the oil pressure gauge.
Tom

So my guess too is that 10w40 is too thick;if so whats a weight?

does it go up with the key turned on and the engine off? if it does, the pressure sender need replacing.

The oil pressure should be high when it is cold started. Unless you in in some frigid climate, 10w40 be fine.

I actually have 20W-50 in mine. I had 15W-40, but switched to thicker oil.

Mine is around "1" at hot idle (in park), but when it drive, it it rather low. Around .2-.3 when engine temperature is 100*C and in drive. Manual states that .3 at hot idle is OK. ??