Outer Limits 4x4 Board

Hi all
My oil preasure typically runs middle to top of the centre third of the guage(make sense??) My mates runs at the very top of the last third.(almost off the guage). Which if either is normal. Both are diesels.
Thanks in advance

Yep ok thanks. So mine with mid range oil preasure is fine but my mates is to high. What is the problem with high oil preasure. what damage can result?

DR Frankenstine wrote:Yep ok thanks. So mine with mid range oil preasure is fine but my mates is to high. What is the problem with high oil preasure. what damage can result?

The gauge and sensor are unreliable in these. Before you make any decisions ,check it with a mechanical gauge that can be plugged into the engine block where the oil pressure sensor currently sits.
Do the test outlined in the manual.
I think they should hold a minimum pressure of about 30 psi for 2 minutes at 2500 rpm warmed up.
Maximum is about 80psi which you will get with a new engine.

I think its the same for most landcruiser engines,diesel or petrol.
CHECK THE MANUAL.

Doc,

Had a 84 diesel 60 series 350,000 hard km'ds on the clock. Motor was never a problem and oil guage was between half & 3/4.

Roota

DR Frankenstine wrote:Yep ok thanks. So mine with mid range oil preasure is fine but my mates is to high. What is the problem with high oil preasure. what damage can result?

The problem on these engines is the releiefe valve.

The valve is a plunger witha spring behind it, eventually the plunger either wears a step in the bore or the plunger wears one edge down so it starts to stick.

The other thing I think occurs, is when the bore wears oil can easily get down behind the plunger. This results in an equalised pressure both sides of the plunger which prevents the plunger from doing what it needs to do.

The design is somewhat flawed(in my opinion) in that the plunger itself blocks the spill passage (until its pushed back far enough to expose the spill passage), and there is no other way for oil behind the plunger to spill.

Something I think could solve this proiblem is if you were to relieve the pressure behind the reliefe valve so that the problem I mention above can never occur. A simple external way to do it could be to drill the cap that holds the plunger and spring in, and run a small line back into the sump. Would only need to be a very small line as we are not talking about huge amounts of oil leaking past the plunger.

The other way i have had suggested on this forum is to remove the timing case, and drill another spill passage further down the reliefe valve bore where the plunger does not cover it. Of course, removing the timing case is a pita :(