spudboytim

iTrader: (3)

Hi guys, im looking for some advice. On a recent mapping session my (track/sprint) 96 classic type ra developed some problems, a cam seal leaking on to the exhaust headers been one!!

BUT THE MOST WORRYING WAS CRAZY HIGH OIL PRESSURE!!

The oil pressure went of the scale!! as the revs increased, its a aftermarket gauge and sender unit but im not sure if thats the problem as the gauge seen to follow the revs quite consistantly!!!

My biggest fear is that tiny bits of metal have entered the oil pressure release valve causing it to stick shut and cause mega pressure!! Ive heard of the valves sticking open causing low pressure but never one sticking shut!!!

My pump is standard but with a modded valve.

The garage isnt open until the new year now so im not going to any answers until they get chance to have a look and ive left the car there so i cant have a look myself. But struggling to wait until then and im worrying that the engine is goosed!!!

Can you guys shed any light on this or have you seen or experienced anything similar???

This scooby ownership has aged me 10 years already!!

Many thanks tim.

Jimbob

iTrader: (13)

Get a decent pressure sender and gauge, the cheap gauges are more for show than anything else.

What was the gauge displaying though??

TH3_5T1G

iTrader: (15)

What pressure does your gauge measure up to?

First thing i would were it me, i'd try another gauge/sender. But obviously, avoid running the engne too much to avoid further seal issues until you have a more accurate way of testing

spudboytim

iTrader: (3)

Hi, thanks for the quick response!!!

The gauge was reading normal at tickover, but as revs increased it ended up off the scale 150psi i think.

If it was the sender id perhaps expect it to work then not, making the needle jump about etc but it was fairly consistant with rpm/throttle.

I hope this makes sense.

Tim.

TH3_5T1G

iTrader: (15)

I know what you mean about the sender Tim but as it's the cheapest option and it's a possibility, i'd try it.

Your cam seal leaking could be a result of very high pressure, but could also have been coincidence.

FWIW, my first oil pressure gauge went within 5 months of fitting, pressure would go along with revs, some days it would be 2-3 bar behing actual oil pressure, some days 2-3 over.

spudboytim

iTrader: (3)

Hi bud,

The trouble is with this subaru ownership is you always fear the worst .

Im hoping like you say its something simple ie sender. No doubt ill find out in the new year but it seems like a long time away.

Im in good hands with the guys at teg sport and steve simpon and i have no doubt they will get me fixed up in the new year.

Just need to control the engine failure demons in my head!

Tim.

merlin24

iTrader: (1)

Have a look at your oil filter - if the relief valve has jammed shut,then the oil filter will 'balloon' out due to the excessive oil pressure if it has been hitting 150 psi.

Mick

spudboytim

iTrader: (3)

Hi mick,

Like you say the filter will give me a fair indication so ill check that out in the new year. Wish id brought the car home with me know so i could do some investigating over christmas! Anyway im sure the guys at teg sport will find the problem after crimbo. Lets just hope its not serious!

Thanks for the input guys, much appreciated!

merlin24

iTrader: (1)

The only trouble with the modified 'straight bodied' PRV is it can be prone to sticking if there is the slightest bit of dirt/carbon/sealant in the system as it tends to drag it up the side of the PRV body.
The OEM PRV has a 'waisted' body design and seems to clear things like that better.
Hopefully nothing serious with yours and the crew at Town End will sort it for you.

Mick

spudboytim

iTrader: (3)

Hi mick,

As far as i know the pump and valve are standard so should have the groove in the piston like you said, but it has a small washer put in the prv body behind the spring. To my way of thinking this increases the spring tension helping to make sure it shuts and reduces the tendency for it to stick. But like i said ive never heard of one sticking shut b4, only open. (low pressure)

On the other hand the extra tension will increase the pressure needed for the valve to open in the first place thus raising oil pressure very slightly?
But this wouldnt explain the huge increase in pressure and the valve has worked fine up to this point, and not been a problem.

Anyway dont suppose there is any point in worrying its christmas after all!!!

Tim.

merlin24

iTrader: (1)

Shimming the spring stack is pretty common but you shouldnt go beyond 2mm (each std washer @ 0.97mm) due to coil bind.
Shimming does increase the pre relief pressure a little as you correctly said but shimming wont be your problem/cause.
Would imagine a new oil pump would cure your problem if the PRV or the PRV bore in the oil pump is scored.

Have a Good Christmas anyway

Mick

spudboytim

iTrader: (3)

Hi mick, thanks for the advice and input, very much appreciated you

obviously know your scoobies!!! Lets see what the new year brings

and ill keep you posted on the findings!

Cheers bud, Happy christmas to u and urs!!

Richard Olafsson

Hi, did you get to the bottom of this? Was it the relief valve jammed shut? I'm having similar issues..

spudboytim

iTrader: (3)

Hi, yes i got to the bottom of it and it was something very simple in the end. On the bottom of my sender unit the wire was loose and was making a bad contact thus giving the odd readings. Hope this helps. tim.

Richard Olafsson

Lol, lucky for you an easy fix then! Mine turned out to be the PRV jammed shut...