TheSamba.com :: View topic - 72 Pressure control valve-Where??!

Wed Jul 02, 2003 6:57 am

Greetings-
I am trying to find the pressure control valve (not the valve that bypasses the oil cooler) on my 72 1700 VW Bus engine. Bently shows a picture (figure 9.1 to be exact) that he states shows where the valve is but I couldn't tell at all from the picture. How to keep your VW alive has a nice diagram but it only applies to pre 72. For the 72s and later it just says the valve is located between the pushrod tubes for #1 cylinder.

Ok so I looked between those pushrod tubes and saw this large looking star-type bolt (ie not phillips, or hex, or flat head [like the bypass valve for the cooler]). It looks to be kind of a pain to get at, and I have not seen a patten like that before on a bolt head (must have a dozen or more points). Is this the plug for the Press Control Valve? I can't seem to see anything else that could be it.

If that is it, what tool do I use to remove it? It looks like I would need to use a U-joint on my socket set with this special "star socket bit" attached.

Many thanks to any advice and suggestions.
Dave

Wed Jul 09, 2003 7:31 am

Ok. That Strange bolt pattern is a 12 point bit. Autozone sells a set of 4 metric 12 point bits. The largest(12mm) fit in the bolt, though it seemed too small, perhaps the bolt was worn. But with a little finesse I did get it off and that was the pressure control valve.

And the valve wasn't stuck. So that was not the cause of my overall problem of overheating.

Wed Jul 09, 2003 8:55 am

check your timing

Thu Jul 10, 2003 7:26 am

Well the timing has been set at a couple of different places. Not knowing any better I went with How to keep VW alives recommendation- I think its 5 or 7deg ATDC for that model year (72,MT).

Then after cruising on the web some and looking at my engine, I saw I have a mechanical only distributor not the kind w/vacuum that originially was on the engine, apparently. So I think it is a 009(not sure how to verify that) and so I set the timing (as I found recommended on the net) such that it has a total advance of something like 27 or 30 deg-which leaves me with an idle timing of roughly 7deg BTDC. I forget the exact numbers.

However, the engine temperature is behaving the same regardless of the two different timing settings. BUT with the 009 setting, I definitely notice that the engine runs alot better and has tons more power.

I could go into further detail (there is an earlier post from a couple of months back) about the overheating as it is becoming very vexing for me to figure it out after several months of tinkering/tuning/cleaning. If you are interested...
Cheers!