Fitted oil pressure gauge - the reading is off the scale!!

Hi

Mk 1 with ABF

Today I completed fitting a Stack mechanical oil pressure gauge (0 - 100psi) by adding a tee on the brown sender outlet and now I am "confused.com"

Started it up, pressure came up nicely almost immediately and it sat at 80psi. Great I thought as I always wondered about the engine as it was second hand and I had never heard it running before fitting it and the red oil warning light constantly flashed and occassionally the buzzer sounded. The engine uses no oil and the breather vents very little.

I let it idle and it warmed up and settled at about 75 psi until I revved it and it went off the scale!!

When the revs drop off it goes to 60 psi and then returns to about 75 psi at idle. Rev it again and it will go past 100psi !!!

There is air in the capillary tube but the instuctions dont say anything about bleeding it and state that you simply start it up and check for leaks.

When it is running the pipe into the gauge is air free but when idling it pulls back a few bubbles and when stopped the oil empties from the upper part of the tube immediately.

There is a slight bend up and down into the gauge but I cant see an oil pipeline air-locking as the oil definitely gets into the gauge.

I cant see it being the air or could it be something else like the pressure relief valve is not working or is it the wrong gauge ie: the ABF oil pressure is over 100psi when revving hard or should I have teed off the white sender?

What should the oil pressure be and what have I done wrong?

 

On mine, when oil is cold I have around 80-90psi. When warm at idle, my pressure is aroun 30-40psi. Pressure does change with revs but not as high as 100psi when warm. At cruise at motorway speeds mine sits at around 60-70psi.

What grade of oil do you have? This will affect oil pressure. I have 5w40 fully synthetic and I noticed I had higher pressures with 10w40 especially when cold.

 

Is it? I'm surprised, thats a very high pressure?

It needs to be driven around but I am amazed if its 70 - 80 psi at idle?

I keep thinking its either a faulty gauge or the pressure relief valve is fubar`d

 

He was saying it was high when warm, and at idle.

 

Sorry, I meant warmed up a little so the idle settled as it is `fluffy` for a minute or two as the ISV is dodgy, it was in my garage as it was late and raining so I didnt run it for long perhaps a minute or two.

However I cant believe it goes that high but I may be wrong as the idle pressure is around 75psi

I suppose I need to give it a damn good spanking but worry if it will burst the gauge.

I`ll warm it up fully at idle at the weekend and see what happens.

It has 10-40 GSF (is it Titan? - was called something else I think but got re-named) semi-synthetic oil in it.

 

you don't need to spank it , just let it warm til the fan is cutting in and out , and see what the reading is like then .

 

Hi Tristan,

Will do and will report back but I suppose if its initially high when cool I wondered if it will overstress the gauge when you simply start up and drive off (without spanking it)

Hopefully it is ok and the readings suggests that the engine is a good `un.

I must look up what oil rating it should be as I assumed 10-40 was about right for an engine with a few miles under its belt but it doesnt leak, vent or use any oil at all.

 

You should be using a cheap oil to run in. Non synthetic.

 

aye a basic supermarket special mieral based would do .

 

Sorry chaps when I said a few miles I meant it as an underststement in that it has done a few miles - many - around 60,000 according to the bloke I bought the engine from. See my first post.

I must be clearer when posting but thanks very much for your continued input.

 

Happy Xmas all,

Took it out yesterday, warmed it up a bit at idle and it settled at 80 and went to 90-100 when revved but when nice and toasty after a thrash it idles at 28psi and at high revs its around 87psi constant and 45-50 when cruising around town and fluctuates nicely (follows) with engine revs so I think the job and the engine is a good un

 

~That's prettyt much exactly as you'd want it . You don't need mad high pressure at all really , my rally car lives happily at 60psi hot , at rpms , and thats a DOHC 16v!

 

Just another question..............

I`ve fitted the oil pressure gauge mechanical pipe into a tee at position 1 on the bottom photo below

I`m fitting a Stack oil temperature gauge with a sensor similar to this...................



I am sure its ok but I am going to fit the temperature sensor into position 2 as per the photo below however as it projects further into the gallery I wonder if it would affect the flow?

 

I dont have a tapping there on my ABF ???

All I have is two senders ech side of the water take off above the flywheel and two oil pressure senders and a water temp sender (I assume) on top of the oil filter housing.

Below is a piccy of the engine before cleaning and fitting to the car.

 

You do!! It will have an allen key bolt in it.

 

Ok, thats interesting thanks

If I leave it at position 2 do you think it will be ok?

Bearing in mind its built for trackdays, I am thinking of losing the 0.3 bar switch as its too low if on full chat to get a warning that late [and if it has only 5psi at idle the pump is knackered or the journals are worn] so as I have healthy pressure on the gauge and it idles warm at 25 -28 psi I was thinking of using only the 1.8 bar switch so if it dropped to idle pressure when on full revs I`d get a warning. I`ve fitted a socking great LED for just such occasions and have bypassed the in dash one.

Any thoughts?