hole near pushrods on case

[914Hugh]

I am in the midst of tearing down the engine and, after taking off the p&c's, I found a mysterious hole with nothing connected to it!

It is located on the left side (near the thermostat) directly between the holes for the pushrods and I'd guess about 1cm in diameter.

Anybody know what this hole is for? Thanks-Hugh

[JP Noonan]

I'll take a look at my cases tommorrow but OTTOMH I'd say it is for the thermostat pulley, or is a hole that is usally pluged with a big Torx type bolt.

...or it is the center case bolt hole. There are something like 22 bolts holding a T-4 engine together. Get out the carb cleaner and spray all the gunk out of the hole and see if there is a bolt at the bottom of it.

[914Hugh]

Thanks for the try JP. In looking back, I didnt give you much to go on. Here is a photo of the mystery hole (case is a '76 2.0) directly between the rear pushrod holes and behind the thermostat.



There are no threads and no screws or bolts at the end of the hole. However, there is a single groove in the middle. I was guessing a sensor hole but I do not recall removing anything from this location (we'll see how much else I do not recall when I put this baby back together soon!). Any ideas? Thanks- Hugh

[SteveStromberg]

911 911 There is a large plug that should be there. Did you get this motor in pieces? Clean area look are there bit's of the old parts still stuck inside? That Hole is where the Oil Pressurer Control Valve is.You must fix this as a stuck OPCV will blow the Oil seals at start up.Is the block covered with oil?Did it blow the Oil Coller? these are two signs of stuck valve. Steve www.914underground.com

[Dave at Pelican Parts]

From what I have heard, some engines did not have the lower oil pressure piston and spring. It was not made clear to me if the hole was simply not drilled in the case, or if it was simply plugged without any piston or spring, or what.

But it is possible that it is not a huge problem. Still very much worth checking.

--DD

[roadtrp204]

The new case I got is the same way. After I did some checking around when I couldn't find the second oil control valve, I found that VW modified the oil system which no longer required the use of the lower oil control valve. The hole is simply what the case looks like from the casting mold without the machine work for the valve. Just behind it on the bell housing flange is a casting for the mechanical fuel pump, on the early carb (vw van/euro 914) models. Same thing, just something from the past that is no longer used. So no worries about the hole, it is blind. With any luck, these cases have a slightly better oiling system (slight if any) over the earlier ones, or maybe it was a modification for the hydraulic lifters that were to follow in the vans.

------------------
Chris
75 914 2.0L

[This message has been edited by roadtrp204 (edited 02-12-2001).]

[914Hugh]

Thanks for the input. After getting responses here and reading in Tom's book about the addition of a second OPRV to later cars, I was a bit nervous! The hole is definitely a 'dead end' as I found out after pouring some oil in there just to make sure.