oil pressure valves in the case...

[bugnut68]

I know the function of the pressure relief valve, but what is the role for the pressure control valve?  More specifically, what would the behavior be in the even the spring for the pressure control valve is not strong enough?

[bugnut68]

Anyone?

[TexasTom]

Had you referenced the Bentley Official Manual you would know this:

The pressure relief valve is forced down when oil is cold and thick due to increased pressure. This allows oil to go directly to the bearings from the pump bypassing the oil cooler to protect it from possible bursting.
The oil pressure control valve is forced down onto spring tension when the oil pressure rises above the point necessary to supply lubrication to the bearings allowing oil to be returned directly to the crankcase sump. It ensures that oil pressure will remani constant at the bearings regardless of engine speed ...
At 20.20mm loaded length, the loaded tension should be 7-8 1/2 lbs.
 

TxT

[bugnut68]

Can't reference the bible from work...lol.    I have read that part of the Bentley manual, but my question is what would the symptom be of a weak control valve? My new 2017 is putting out 25 to 30 PSI on the gauge cold, and warming up it's less than 10 PSI (idiot light on at idle by this time)...I'm hoping it's a simple fix of control and/or pressure relief valves and not some strange gremlin inside.

[bugnut68]

I failed to get a mechanical gauge connected to my engine tonight, primarily becase of cheap, shoddy hardware, but the fact is this: the electric gauge in the car reads 25 PSI dead cold at idle and drops down as the engine warms up.  Once it's up to operating temperature, it's down low enough to trigger the oil idiot light.  The VDO two-pole sending unit says that it triggers the light at 6 PSI plus or minus 2.

Would using the wrong oil pump gasket cause this kind of problem?  I've got two in the shop in my stash but they both measure in at .104" thick.  I watched that on assembly, so I highly doubt that's what's wrong, but I'm just trying to troubleshoot.

[TexasTom]

Are you using a new case or used?
Standard or line bored?

This can occur when the plunger seats on the case are worn or damaged or the channels /plungers are worn or damaged. Also if the tolerances are 'loose' on a used or remanufactured engine case and/or, as you questioned, the springs are weak & out of tolerance.
Perhaps your easiest test, outside of a mechanical gauge, would be to replace the control valve spring with a new or higher tension spring? Pretty easy swap to see if theres a difference ...

Unfortunately, there may be no quick and permanent fix if the case has been improperly machined, only bandaids.

[Bruce]

Likely it is your gauge that's way out.
I use the same two post sensor feeding a VDO gauge.  My gauge reads ZERO at idle when it's warm, but the light is not on.
I suggest you remove the gauge and put a stock oil pressure switch.  If it doesn't turn the light on at a hot idle, you're ok.

[TexasTom]

I suggest you remove the gauge and put a stock oil pressure switch.  If it doesn't turn the light on at a hot idle, you're ok.

So true ... and even simpler!

[bugnut68]

Are you using a new case or used?
Standard or line bored?

This can occur when the plunger seats on the case are worn or damaged or the channels /plungers are worn or damaged. Also if the tolerances are 'loose' on a used or remanufactured engine case and/or, as you questioned, the springs are weak & out of tolerance.
Perhaps your easiest test, outside of a mechanical gauge, would be to replace the control valve spring with a new or higher tension spring? Pretty easy swap to see if theres a difference ...

Unfortunately, there may be no quick and permanent fix if the case has been improperly machined, only bandaids.

It's built on a used case, and it has been line bored (.060").  I'm well aware I started with a less than ideal base, but it was what I had, and I had it inspected by professionals who said it should be fine for what I planned to do with it.   Getting to that control valve is going to be tricky, as it's partially obstructed by the Scat 1.5 QT sump, but I'll do what I have to do to get this figured out.

Once my head cools off a bit, I'll likely try again to get a mechanical gauge hooked up...I just have a hard time buying that with such little run time this thing is having oil pressure issues already, but perhaps the case has issues inside that I'm not aware of.

[bugnut68]

Likely it is your gauge that's way out.
I use the same two post sensor feeding a VDO gauge.  My gauge reads ZERO at idle when it's warm, but the light is not on.
I suggest you remove the gauge and put a stock oil pressure switch.  If it doesn't turn the light on at a hot idle, you're ok.

My light eventually comes on once the engine gets warm enough, and guessing by the sending unit, that could be anywhere from 6 to 8 PSI, as that's the tolerance indicated on the side. 

[bugnut68]

And the verdict is in... mechanical gauge verifies the accuracy of the electric gauge.  25 PSI cold and/or having barely idled for a minute or two at most, and only going to drop from there as it warms up.  Switched out the pressure relief valve with a stock-sized spring and different plunger (apparently the one I had in there that came with the case when I bought it was a longer booster spring) to no avail.  Couldn't get to the pressure control valve as the sump is in the way...but I doubt that's my issue anyway, after having read through the Bentley manual.  Awesome.

[Donny B.]

I would bet the case is a lost cause.

[fredy66]

sorry to hear that hope you get it fixed and  don't loose fate.
remember that it only is a hobby .

[Jon]

If your pressure control valve is stuck slightly open you can get the problems you are having.
There is no chance you have swapped the pistons and springs?

[Mike Maize]

I agree with JHU. My low mile German FI case had a increase in "warmed up" idle pressure by resurfacing the seating surface of the plunger at the bottom of the bore during a tear down. It holds around 9-10 LBS at 700 rpms now and used to get pretty low. I would think it is worth checking before tearing it apart.

[bugnut68]

The weird thing is not too long ago, while the engine was still on the Zalex test stand, the oil pressure through a mechanical gauge read 40 PSI cold and settled down to 15 PSI at warm operating temperature.  The only thing I've changed since putting the engine in the car, in hindsight, is the oil lines; I had rubber lines on the stand, and installed stainless lines (they're not kinked) once the engine went into the car.  I don't know what factor this could play, but highly doubt the stainless lines are too small in diameter.

I have the relief plunger tool from aircooled.net, so I suppose I could try to ream the passageway and see if that makes difference, but the fact that it had oil pressure at one time and all of a sudden started dropping down would indicate that the relief valve was working fine at one time before.

[Zach Gomulka]

It's built on a used case, and it has been line bored (.060")

Whoa. I know you don't want to hear this, but that's "ok" for a stocker, but not for something that's putting out 3x the power. Just my two cents, sorry

[bugnut68]

It's built on a used case, and it has been line bored (.060")

Whoa. I know you don't want to hear this, but that's "ok" for a stocker, but not for something that's putting out 3x the power. Just my two cents, sorry

That was my first instinct, but VW Paradise inspected it and I talked to Jason about it... he said it should be fine, though confirmed the case was getting close to the end of its life.  I've got just a couple things left to check before I throw in the towel and walk away from this thing for awhile... I remembered earlier this morning that I had rubber oil lines on the engine when it was on the stand, and switched to stainless lines once the engine went in the car.  That's the ONLY thing that's changed since the engine was on the stand, and perhaps its' not a factor, I don't know... but I'm prepared for this engine to be a big paperweight at this stage.

[clarkey]

Check to oil pump hole in relation to the crankcase. If they don't line up that could also be the problem. Also, what type of oil are you using? Cheers Clarkey

[bugnut68]

Check to oil pump hole in relation to the crankcase. If they don't line up that could also be the problem. Also, what type of oil are you using? Cheers Clarkey

That looked good on assembly, plus I would think it would have shown up immediately rather than later.  I'm running 15W-40 Delo oil with Lucas Zinc/ZDDP additive.

[bugnut68]

It's built on a used case, and it has been line bored (.060")

Whoa. I know you don't want to hear this, but that's "ok" for a stocker, but not for something that's putting out 3x the power. Just my two cents, sorry

That was my first instinct, but VW Paradise inspected it and I talked to Jason about it... he said it should be fine, though confirmed the case was getting close to the end of its life.  I've got just a couple things left to check before I throw in the towel and walk away from this thing for awhile... I remembered earlier this morning that I had rubber oil lines on the engine when it was on the stand, and switched to stainless lines once the engine went in the car.  That's the ONLY thing that's changed since the engine was on the stand, and perhaps its' not a factor, I don't know... but I'm prepared for this engine to be a big paperweight at this stage.

For clarification, I am NOT by any stretch making any kind of complaint against VW Paradise, not by a long shot.  This is one of those things that can't be predicted until it's all together, ultimately.  I only wanted to point out that the initial inspection/prognosis was that it should be fine, just in case there's any misunderstandings.  If I decide to tear it down and build on another case, they will have my business again for the machine work.
My dad had his 'h' case in his '68 rebuilt again and again until the head studs finally started to pull on the most recent rebuild; not sure what the line bore was at on it at that point, though. 

[Jim Ratto]

do you have the thick oil pump gasket between cover and oil pump?

[bugnut68]

do you have the thick oil pump gasket between cover and oil pump?

I'm 99 percent sure I don't, as I was consciously thinking about that during assembly... do you know the thickness of the two gaskets, by any chance, JIm?  I've got a couple gaskets sitting around leftover from my gasket kit that measure .104" in thickness... just curious what the difference in thickness is between the two different ones (case to pump and pump to cover).

[Jim Ratto]

dude- .104" thick is like a head washer. Check it, you should have the (very) thin gasket there. Check drive gear in pump while you're in there.


Did you plug pump and case too?

[bugnut68]

dude- .104" thick is like a head washer. Check it, you should have the (very) thin gasket there. Check drive gear in pump while you're in there.


Did you plug pump and case too?

Will check again, I may have mismeasured when I checked the other night, or I may be thinking of something unrelated; its' a busy deadline day today, lol.  I'm fairly sure I have it correct, but will check it out. 

And yeah, both the case and pump were plugged for full flow.

[Nico86]

Did you plug pump and case too?

Do you put that plug here?

[Jim Ratto]

Yep!

[Nico86]

I've also noticed that the fitting for the full flow on the case acts like a plug on the top of this oil galley (on my case, since I've shortened the case at this place for cleareance with the pulley and pulley tin).
Would you still plug on the pump side?

[bugnut68]

Did you plug pump and case too?

Do you put that plug here?

Yes, sir, been there, done that!

[Zach Gomulka]

You must mean .004" for the pump gasket...