OPRV Sleeve

[PhilKent]

Anyone know a source for the steel sleeve that is a push fit in the engine block that the Oil Pressure Relief valve fits into?
It doesn't appear to be available from Porsche....

 

[PSH]

Hi Phil

It's been a while since I did mine, is it a plain tube or does it have oil holes drilled/machined grooves? I just can't remember.

If you can't find a source I would take accurate measurements of ID, OD and length and then check what's available in the precision ground steel tube that's available.You may get lucky and find just what you need.

Kind regards

Pete

 

[PhilKent]

Yes, I've taken measurements. It's a pretty standard size plain tube by the looks of things. 17mm ID, 20mm OD 25.4mm long. Polished inside for the OPRV valve piston to slide (I used to have the old 3 piece OPRV, since replaced with the 1 piece, so the smoothness is not so critical now). I will either find a standard tube to fit or if needs be turn one out on a lathe and give it a polish...

 

[vitesse]

I thought that the sleeve was made redundant when the 1 piece self contained valve was used .

 

[PhilKent]

I'm not sure that can be correct, if the sleeve wasn't there at all then oil could bypass the pressure relief valve making the valve itself redundant. The 1 piece has an o-ring to fit the sleeve. It is possible later blocks don't have the sleeve but the casting is modified to fit the 1 piece, but I doubt that.

 

[Waylander]

Don’t forget it will also need to machine two grooves for the sealing rings for the block and filter housing

 

[marojojoem]

A quick question, if the OPRV is malfunctioning, what are the typical symptoms?

 

[PhilKent]

High, or low oil pressure, or erratic (the old style were prone to 'sticking' occasionally in my experience, with clear signs of wear marks on the piston).
Waylander - I think you're thinking of the guide sleeve, item 944 101 181 01 which is still available.
I was after the tube that sits near it. There is no image in the pet catalogue and speaking with Porsche they couldn't help.
Weirdly, I also needed 928 101 195 03 which is a 'fitting bush' that one of the crank studs sits within, but what I seem to have got is the part I needed. I'll now have to make the fitting bush from another piece of stainless pipe...

 

[marojojoem]

Thanks Phil, The problem I am trying to chase down is that the oil is draining down to the sump so when I restart after the car has been standing for a day or two there is a significant wait for the oil pressure to build up once the engine has started. After that its fine. Sorry to hijack the thread but I was hoping that changing the OPRV might do the job.
Mark

 

[PhilKent]

Found the guide in the manual for the sleeve I'm talking about. I did indeed use grip pliers to remove it, but in doing so it knackered it.

Regards the slow oil pressure, I would think first port of call is the OPRV as it's the easiest, then it would be the check valve in the cylinder head, but I'm no expert, so this is not technical advice

 

[scam75]

Thanks Phil, The problem I am trying to chase down is that the oil is draining down to the sump so when I restart after the car has been standing for a day or two there is a significant wait for the oil pressure to build up once the engine has started. After that its fine. Sorry to hijack the thread but I was hoping that changing the OPRV might do the job.
Mark

Again no expert but I believe some oil filters that fit (non OEM) allow the oil to drain away down after switch off. The proper filters have some kind of valve that prevents this. Maybe someone else can clarify.

Stuart

 

[marojojoem]

Hi Stuart, I heard that too so I've changed the filter but sadly no change to the problem. Mark

 

[Waylander]

How do you know the oil pressure is slow to build, don’t rely on the dash for that information
the only real way is with a wet pipe type gauge, a T connection and plumb one in
the electronic sender may well be at fault and not anything else

the other issues might be a hairline crack in the pick up pipe or a worn oil pump (unlikely) or a leak where the locktite has failed between the oil pump and the face of the block

 

[marojojoem]

Thanks for the thoughts and apologies for responding slowly to this I've been abroad.
Agreed I'm just relying on the gauge to tell me this but the top end does suddenly go quiet when the gauge registers the pressure so I think it is a real lack of oil rather than anything else. Once its there the pressure is consistent and good so I've ruled out cracks in the pick up or leaks, Im convinced the system is draining down into the sump when the cars standing.

Mark

How do you know the oil pressure is slow to build, don’t rely on the dash for that information
the only real way is with a wet pipe type gauge, a T connection and plumb one in
the electronic sender may well be at fault and not anything else

the other issues might be a hairline crack in the pick up pipe or a worn oil pump (unlikely) or a leak where the locktite has failed between the oil pump and the face of the block

 

[PhilKent]

So, in my turbo engine re-build I'm replacing the head with an N/A head and it's been pointed out that the check valve in the N/A head has a larger bore than the turbo head (2.5mm dia vs 8mm dia). Interestingly the workshop manual states that when replacing the check valve only the turbo check valve should be used, so perhaps worth considering this if you ever need to remove the cylinder head.

 

[Eldavo]

You’re welcome []