87S with oil leaks galore

[Northern944s]

Hey,

Very new/inexperienced with this car hoping to get some info on an oil leak. Can you tell me what this bolt is? Is it a mounting bolt, or something else? There are drops of oil coming from the bottom of it. I was hoping to just tighten it but don't even know the torque or what it is.

Overall, there isn't enough oil to be showing on the driveway, but the engine is wet.

Thanks

[jtehfreaks]

I'm pretty sure that's the oil pressure relief valve. You probably need a new crush washer; at least the valve itself isn't going out, they aren't cheap.

[Projekt425]

OPRV-Oil Pressure Relief Valve. Go to:
Clark's Garage Home Page
And you'll get some good info. Change the crush washer and the O ring and if you're feeling ambitious you can rebuild the thing. There is another O ring inside of the 87-+later version that I've changed. It's not a tough job all together and a job most DIY guys can do.

[v2rocket_aka944]

OPRV.
Try tightening it just a little bit more and seeing if that works...
If not maybe a crush washer...although being a "low point" it might just be a leak that has migrated there from somewhere else.

[JD159]

New S owner??? Change the o-rings on the oil pressure relief valve in the back of the cylinder head plz. Can be removed with an allen key and a flat head.

[djnolan]

Originally Posted by JD159

New S owner??? Change the o-rings on the oil pressure relief valve in the back of the cylinder head plz. Can be removed with an allen key and a flat head.

I remember reading about this. Is it under the valve cover?

[kevingross]

DJ, that's a different valve but yes there's one in the head, under the valve cover. The one in the photo is the oil pressure relief valve, as others noted.

Are you sure it's leaking? That would be a little surprising unless it was not torqued down. Given the location, I'd first assume that stray oil is left over from an oil change. Check the OPRV for snug. If you decide to remove it and replace its crush washer, as Projekt suggests you are probably best replacing its o-rings as well, since they are likely hardened and may be damaged during the removal.

I have Al Broadfoot's service procedure for the heat exchanger in the FAQ, and it includes info on the seals. Take are look here. Good luck!

[Projekt425]

This is the OPRV in the head. Good luck finding it if it's been removed.

[v2rocket_aka944]

^^^ there's a "restrictor" in the 8-valve cars 82-88 and a sort of check/relief valve in the 1989 8-valve head.

there is a restrictor in the 944 2.5 and 3.0 16-valve heads.

interestingly, there is no such restrictor or valve in the 928 heads of almost identical design and they don't have any real "chain tensioner" issues..

[Northern944s]

Thanks everyone for the replies. I checked the OPRV and it's really tight, so probably not leaking from there. There is quite a bit of oil in the vicinity, but unless I wash the whole thing it'll be nearly impossible for me to tell where it's coming from. And let's be honest, there is probably more than one leaky spot. In any case, it's not showing up on the driveway, so it can't be so bad .

[pfarah]

It might be coming from the lower balance shaft cover.

[djnolan]

I have no idea what the 16 valve motor pressure reducing valve does or what damage it can cause but here is the manual page on repairing it...

[JD159]

Originally Posted by djnolan

I have no idea what the 16 valve motor pressure reducing valve does or what damage it can cause but here is the manual page on repairing it...

Perfect! Exactly what I was talking about.

I'll find the post that has the o ring sizes.

Overtime the o-rings get hard and brittle, and oil will flow past the o-rings and not into the channels resulting in a loss of top end pressure.

The oil gauge will show fine pressure, but your lifters and cams will starve. Ask me how I know...

[JD159]

Here we are. See this post.

https://rennlist.com/forums/924-931-944-951-968-forum/313183-pressure-reducing-valve-what-can-you-tell-me.html

I also got new O'Rings for it. They are not listed in the PET. The correct sizes and anybody reading this later can order them with the Parker o'ring numbers: 2-013 and 2-014. Get them in Viton and you should be good.

[djnolan]

Yeah I have been hearing some rough noises from the cam cover area, will definitely pull the cover and take care of this.

What does "micorencapsulated, renew if necessary" mean in reference to the set screw? Use some type of thread sealant?

[JD159]

Originally Posted by djnolan

Yeah I have been hearing some rough noises from the cam cover area, will definitely pull the cover and take care of this.

What does "micorencapsulated, renew if necessary" mean in reference to the set screw? Use some type of thread sealant?

Perhaps. I noticed what looked like blue locktight, but I just tightened it as per the instructions.

[Projekt425]

On the Porsche PET it's called a "pressure relief valve" but it's main function is to regulate the flow of oil to and fro. So whatever we call it there seems to be a lack of info regarding what years it's installed in. I've seen the PET with it listed and without it listed. I haven't seen Pelican offer it either.

[JD159]

Originally Posted by Projekt425

On the Porsche PET it's called a "pressure relief valve" but it's main function is to regulate the flow of oil to and fro. So whatever we call it there seems to be a lack of info regarding what years it's installed in. I've seen the PET with it listed and without it listed. I haven't seen Pelican offer it either.

Ya there really isn't a lot of info about it. I suspect as more and more S cars develop noisy lifters and potential failures, it'll become more well known. I can confirm that the o-rings I listed do fit and work great.


Also, it is limited to S model cars.

[djnolan]

I m not sure if the valve shown in post 17 is the same as post 12. T

The valve shown in post 17 diagram says for engine 44.07/8/9/10 and it also says 924S. Is this an 8 or 16 valve motor?

The valve shown in post 12 is for engine 44.40. Is this the 16 valve motor?

Also the post 12 valve is round with 2 o-rings and post 17 is square with 1 o-ring.

I have a call in to pelican to clarify...

[JD159]

The valve in both those posts is only on the 16V models. Do you have the valve cover off? If so, send over a picture and I can point it out.