Thanks Craig. Pretty much what I thought. What did you use to cap the nipple on the Y-pipe? Obviously there is a lot of pressure on that port. I thought of tapping it and using a bolt to plug it but some type of a cap with a worm clamp would probably be sufficient.

 

This isn't the #16 valve. It's the Venturi tube that comes off one of the other plenum nipples. #16 is behind the Venturi.

 

well, i'd say the major indication is that massive loss of boost and as we know, a pressure test is the first and easiest way to identify that. so once the symptoms ( boost loss ) are found, surely the next and only next step would be to pressure test. once the pressure is up, you can usually quickly identify a "bad" 16 from the air escaping. i heard mine sorta "whistling".

my other point is/was that in my limited knowledge of how this all works ( and admittedly y'all seem to know vastly more about the valve than i do ) it just seems much ado about very little in terms of frequency of occurrence, and i said as much earlier. but...

if the discussion were about the MAF VS running mafLESS, and dealing with the also occasional maf issues "we" sometime have? ( far more often than a faulty #16, i would venture? ) then i'd understand.

but again, i sure wouldn't mess with the oem setup merely to minimize the occurrence of #16 CV issues. was my original and continuing long winded point. so again, its not a big deal to r&r, much easier than swapping out the plenum though right there.. and you should be able to r&r it in no time and be back running as you should, if that is/was the source of any leak.

and as to the "kit" my friend has a home depot homemade that works great. iirc? i think markski makes/sells them reasonably also. way i see it? with these cars you either should have that "kit", or a friend that does lol. gl with the swap, and btw happy new year!

 

Yup, realize it's a completely different part... Just following up on the thread as it migrated in a slightly different direction.

 

#16 valve is in hand... Unfortunately my six year old Bosch fridge decided to fail this morning so I'm spending time fixing a different 'compressor'...

 

Meaning you removed it and it's in your hand? Or? Good work!!!

 

Nope. It's the replacement in-hand, original still buried deep in the engine compartment.

But at least the fridge is now up and running. Miraculously I was able to find the correct replacement compressor control board locally, on a Sunday, and on New Years Eve day! I'll try and get to the Turbo tomorrow...

 

Good work!!!! Like I've told a few others I wouldn't try to just pull that hose off the valve. I almost guarantee you'll break the nipple on the plenum (I broke mine). After thinking about it I would now have cut the small hose that connects the plenum to the valve in half and replaced the hose.

If you do get it out without breaking it you'll be my new hero!!!

Good luck and cut that hose.

 

I'm more than a little paranoid about breaking the nipple...

 

you can see on the diagram #18 hose connects the nipple on plenum to nipple on #16 valve. If you cut right through the middle of it and take the 2 pieces seperate I don't think there's any way you will break the nipple off the plenum. If you don't cut it. place an order to IPD

the nipple on the plenum and the nipple on the #16 valve have to be almost touching. I would say they are virtually impossible to seperate without breaking something. Unless you get lucky. a 3 dollar hose or a trip to oriellys beats replacing that whole plenum. Unless of course you're going to upgrade to an IPD. that's another ***** in itself but I got mine in.


also don't be afraid to drop that engine down. i'd say you can drop it down 3-4 inches without having to worry about bad things potentially happening. if you just drop it slow you'll know!!!

 

We'll, last night I took off the y pipe, f pipe, diverters, throttle body, power point, venturi tube, etc. to gain access to #16, lowered the engine as much as I dare, and was able to use my cable operated hose clamp pliers to remove one of the clamps on #16 valve, but damn it's still really tight back there and most of the other spring-style hose clamps are rotated in the wrong direction for access.

I don't want to honk on things too much for fear of breaking the nipple, but am also concerned that if I just cut the hose between the plenum and check valve, I'll not be able to get the hose stub off the plenum without removing the entire plenum. Even tighter access to that plenum side hose clamp...

 

Not sure how much space you have but here's a pic showing how much I was able to gently lower the motor. You should be able to get both hands in there

This pic shows the top of the IPD plenum I put in. You can see how much room I have.

 

Any more info on this? Like exactly where I should be watching? right now I have each motor mount nut on with a couple of threads limiting the lowering.

Further pressure testing also showed the Venturi Tube / Suction Jet Pump (996.110.652.70) is also leaking pressure, so ordering a replacement of that as well. Also ordered a throttle body o-ring and two of the other small check valves as they seem to be frequent leak culprits as well that I haven't been able to check yet.

It's a bit frustrating that once you find a big enough leak, like the #16 check valve, it's difficult to go much farther with pressure testing until you tear everything apart, fix that leak, then potentially have to put everything back together to test again... I might try and build a plenum pressure test plate so I can at least test everything down-stream of the plenum before putting the y pipe and everything else back on the car.

 

I definitely had the bolts completely off and if I had to guess I was down an inch from that.

I'm not seeing which coolant line might get popped???

Anyway lower at your own risk but I lowered mine down pretty far !!!!slowly!!!!

I do know this. You can lower it down far enough to get a plenum in and out!!!

 

Well it's out. And you were right... I ended up having to cut it out. The pictures make it look like there is more room to work back there then there really is!

Now I just have to put it all back together. I think I'm going to use screw-type hose clamps instead of the spring type on the check valve to make life just a tiny bit easier if I ever have to do this job again. By the way, the piece of hose between the check valve and the manifold seems to be identical to 3/8" ID fuel line. It's a reinforced hose, not just a rubber vacuum line hose. Probably one of the reasons it sticks on the valve so tightly!

Now i just have to put it all together with the new parts!