Oil Pressure Relieve - Secondary Valve on 1988 Engines

[Tidybuoy]

I had to keep bringing up this subject as I feel that I have been hogging the board all week - But:

I was reviewing Clarks Garage and here's one thing I read:

High Oil Pressure may = Blocked Oil Passage:

Symptoms:
About the only time I've seen this happen is when the check valve for the oil supply to the cylinder head sticks closed. When this happens, it will be accompanied by loud tapping noise from the hydraulic lifters. If the oil passage into the camshaft housing itself becomes blocked you'll typically see an oil leak at the cam assembly to cylinder head gasket.

Check Valve for Cylinder Head.....?

So, I was reviewing my PET Catalog and sure enough, there is a secondary Oil Pressure Relief Valve on '87 & Later Cars - part#944 107 239 01

I looked this up on Pelican and they've got it - with a picture
http://www.pelicanparts.com/cgi-bin/ksearch/PEL_Search.cgi?please_wait=N&forumid=&threadid=&FILTER_944M=ON&FILTER_ACCE=ON&FILTER_CARE=ON&FILTER_STUF=ON&FILTER_PERF=ON&FILTER_MISC=ON&FILTER_GADG=ON&FILTER_TOOL=ON&FILTER_SUPP=ON&FILTER_TECH=ON&command=DWsearch&command=DWsearch&REFINE=Y&FORUM_REFER=&description=94410723901&FILTER_SUPP2=ON&FILTER_TECH2=ON&FILTER_ACCE2=ON&FILTER_CARE2=ON&FILTER_STUF2=ON&FILTER_PERF2=ON&FILTER_MISC2=ON&FILTER_GADG2=ON&FILTER_944M2=ON&FILTER_TOOL2=ON&description=94410723901&x=39&y=9&FILTER_944M=9&FILTER_ACCE=9&FILTER_CARE=9&FILTER_STUF=9&FILTER_PERF=9&FILTER_MISC=9&FILTER_GADG=9&FILTER_TOOL=9&FILTER_SUPP=9&FILTER_TECH=9&FILTER_SUPP2=9&FILTER_TECH2=9&FILTER_ACCE2=9&FILTER_CARE2=9&FILTER_STUF2=9&FILTER_PERF2=9&FILTER_MISC2=9&FILTER_GADG2=9&FILTER_944M2=9&FILTER_TOOL2=9



Can you look at this and tell me what you know about this. I'm wondering if I can access without removing the CAM Tower - per Clarks description, this is exactly what my noise sounds like

[hpservertech]

One thing I have learned (the hard way), is just cause it's listed on the Pelican site, doesn't mean they actually have it or can even get it. Dont assume cause it's listed it's available.

Found that out the hard way.

[944 boy]

That "valve" is a ball check. It is the same as used on the turbos. It is an 88 only feature for the NA's. The valve has to be drilled out and a new one has to be pressed into place. The motor would have had to sit for a very long time or have a rod bearing shred itself in order to clog one. Not unheard of but rare. Unfortunatly you have to remove the cam tower to get to it, but I would not attempt it uless the head was off. And even then I would leave it to a competant motor bulider. I'll see if I can dig up the FSM diagram instead of studying.

[944 boy]

This says that any head can be fitted with the 951 part and I have heard from the NASA spec group that it is more efficient at keeping oil in the cam tower for start-up and such.

[Tidybuoy]

Thanks for the info.

I'm going to first determine if I have an exhaust leak - since the noise my car is making sounds like a combo of valve train/exhaust leak.

It's turning out to be a difficult task since the noise only occurs when I'm driving and I can't seem to get it to do it when idling in the garage.

I took out the cam tower plugs and ran the engine and I can see oil splashing around - everything seems to look normal.

I'm going to order new exhaust gaskets and hardware and will be able to inspect a little better when the pipes are removed - visually, they look fine and I can't feel any exhaust pumping out but there's definately a bad sound when i give it some gas and the engine is under some load.

Thanks again..........Vern

[Tidybuoy]

One more thing...when I view the pelican diagram http://www.pelicanparts.com/cgi-bin/PartsLookup/search.cgi?command=show_page&Catalog_Name=944_2_USA_85_88_KATALOG&Illustration=103-03&Line_Item=33

I see two items #33 is the ball check valve and right next to it is #34 oil pressure relief valve. Can you look at this and tell me if this is waht you were referring to....Thanks

[944 boy]

Thats an either-or situation. The one on the right is what most NA's have, the ball check is the turbo part. Only one is used.