Oil pressure and relief valve

[oldenoughtoknowbetter]

1981 G/S. Following last week's oil leak posting I've checked the oil pressure at Rob's suggestion and surely enough it's through the roof!

Pressure at 800RPM should be around 2 Bar (mine's 5.5) and at 4000 revs, it should be 5 Bar (mine's as high as you like. The more it's revved the more it increases!)

So obviously, the pressure relief valve's sticking shut. Couple of questions:

1. Why might mine produce such a high pressure at tickover? The relief valve opens at around 5 Bar so it should still be closed anyway at 800 revs and not increase the pressure at tickover. But mine's already high at tickover.

2. The pressure relief valve is attached to the crankshaft front bearing carrier but neither Haynes nor Clymer say if the valve can be removed without firstly removing the carrier. It looks as if it just screws into the carrier but is removal more involved than that?

Many thanks.

 

[solidstate100]

1. In a healthy engine the oil pressure relief valve is open (or should be) to a greater or lesser extent all the time the engine is running - the reason is that it is the relief outflow from the valve which lubricates the timing chain/chest area so it is important that you sort it asap!

(I think the pressure you mention on your engine are cold pressures?, and are very much reduced for an engine at normal temprature)

2. Cant remember off the top of my head - others will know tho

 

[Rob Farmer]

Theres an old thread suggesting 75 PSI (5 Bar) is normal when running

http://ukgser.com/forums/showthread.php/154607-Oil-Pressure-Guage-on-R100GS?highlight=pressure

 

[oldenoughtoknowbetter]

Thanks chaps. Obviously the PR valve needs to be replaced. But is it possible to remove the pressure relief valve from the crankshaft bearing holder with the holder in situ?
Thanks.