Karlos G

iTrader: (4)

Noticed tonight that after giving it full beans for about 15mins my oil pressure guage was fluctuating by about 5-10psi at mid/high revs!
So for example if I was sat at 3500rpm the needle would flick back and forth from 40-50psi, at idle it holds it's usual 16psi no problem.
I run Autometer mechanical pressure and temp gauges, oil temp was about 80c and I'm using a genuine Ford oil pump that I bought from Tim (NMS) having only done a couple of thousand miles now totaling around 10k I would say.
Is this normal?

Versus_Creations

iTrader: (1)

try another gauge maybe its sticking.

Karlos G

iTrader: (4)

If the guage was sticking it would do it all the time, not just after a hard run but if I can get hold of another one i'll try it anyway.

Canada1

Hello Karlos,

Certainly try another pressure gauge first.
If the problem persists I would certainly be somewhat worried.
Areas to look at - is enough oil returning to oil pan? Maybe add 1/2 quart and see what effect this has.
Much more oil is left up in the cylinder head when running than one would think.

Perry

Karlos G

iTrader: (4)

Thanks Perry, I had heard that the CVH suffers oil surge quite badly so wasnt sure if it's nornal or not?!
I have of course checked my oil level and it's between the Max and Min marks so should be enough there.
Could be that it's not draining down fast enough as you say, i'll top it up and see what happens!

Canada1

Hi Karlos,

Certainly make sure it is topped up to the max level.
On some V8 engines here over 4 quarts are left up in the cylinder head when at high rpm.
Oil drainback is an issue on nearly all engines.

Pressure surging should not happen unless there is a problem with the oiling system - or oiling system design. Foaming oil will cause oil pressure surging. Not all that good for bearing life.

Cheers

Perry

Karlos G

iTrader: (4)

Foaming had occured to me but thats generally seen when over filled with oil isnt it? Does seem to be after an extended high RPM session that it occurs 5-6k for maybe 5mins or more, perhaps more oil is needed if it's not draining down quick enough?!

Thanks Perry!