Question:

On the two-valve cars, how is the throttle-body and intake elbow mounted? I couldn't find a clear description or picture in the manuals.

I've got my '85 S2 pulled all apart in the garage. I'm rebuilding the injectors, and experimenting with an external oil cooler. While detailing the top of the engine in preparation for SITM I made an incredible discovery: the intake elbow and throttle body are loose- they can move back and forth about 1/2 inch! It appears that if I tighten the clamp between the center body of the "spider" and the throttle body that this loose ability to rotate will cease..but I wonder: I see three bolt heads- one to each side of the throttle body and one towards the rear of the engine...are these bolts supposed to be screwed into the top of the engine?

Now I wonder if my "Rough Running" threads might have been caused by this possible air leak...I swear I tightened all the clamps at one point...though I've never removed the throttle body or elbow, so it's loose from the butteater PO's...

?

Normy!
'85 S2 5 Speed

 

Normy

Here's a couple of pics I took when taking mine apart - excuse the mess but I was the first in here after 16 years!

The elbow is held on rubber isolation mounts so it is firmly held but with a little give from the rubber. The two front mounts are studs with the elbow being held on with nuts from above. If you can see bolts then maybe you are missing the rubber mounts and are bolted directly into the block. I can't remember what the rear mount was but I think it was the same (I will have a look when I get home).

If you are missing the mounts then the TB/elbow will be sitting 10mm low which won't help with sealing against leaks.

<img src="http://homepage.mac.com/potw/.Pictures/TB%20folder/TB%20mounts.jpg" alt=" - " />

<img src="http://homepage.mac.com/potw/.Pictures/TB%20folder/elbow%20mounts.jpg" alt=" - " />

I will also be reinstalling my cleaned intake and rebuilt injectors soon, and for the same reasons. Here's hoping it works!

Cheers
Dave

 

Normy, it's possible that the rubber part of the mounts have cracked and broken. The TB will move around.

 

Son--of--a--b*tch!

Arrgghh!

Dave you hit the nail exactly on the head. The three elbow mounts you pointed out are exactly what I suspected. It is obvious that the three mounts on my engine are connected to nothing! The whole throttle body/elbow assembly can literally rotate freely...as if it is not attached at all. The stud bolt heads on the sides are there, but apparently doing nothing. Now I guess I get to figure out how to get under there to tighten things up...

Thanx again!

Normy-
'85 S2 5 Speed

 

Normy, just to tidy this thread up - this is what the mounts are like. The rear one is similar but has a shorter top stud.

<img src="http://homepage.mac.com/potw/.Pictures/TB%20folder/elbow%20front%20mount.jpg" alt=" - " />

Cheers
Dave

 

Normy, mine were all hardened and sheared off, also. You pretty much have to remove the piece to get at the remaining bits that are left in the block. The good news is that there is so much oily crud down there that the likelihood of a frozen thread is low.
Having said that, the center-low one, on my car, was pretty tight and difficult to get at. If you look closely, you'll see that it's actually screwed into a threaded plug. If you clean really carefully around the top, you will see that it is a hex-head that is countersunk into the block. Once cleaned out, a socket WILL fit in there, bu be careful of the crud. the empty hole is straight down into the block's interior!!

 

Well, after contorting myself for a while, I finally realized that I needed to take off the entire "spider" to get at this thing. I started by going around to each intake tube and seeing just how difficult it was going to be...and I can tell you that I'm certain I could have taken off all the tubes on the left/driver's side, but the other side would be difficult. And I was concerned not only about the gaskets that mated with the cylinder head tearing, but for the rubber intake tubes...the one that I took off revealed to me that these are very hard and likely to crack, and since I don't feel like replacing them right now...I let it alone.

I discovered that indeed, the rear mount is some sort of stud. Via finger, I could not get it to start into its hole in the block. I decided to simply torque the hell out of the clamp that was originally loose [center body to throttle body], and this secured the elbow and TB. I'll let this alone for now...a fight for another day.

Thanx for the outstanding help and pics!

N

 

Normy

There is a 'proper, in the manual' way to get in there without removing the spider, by removing the centre plenum box and leaving the legs in place. loosen the hose clips that hold the rubber at the top of the legs, then push the rubber back onto the legs freeing the central box. If you disconnect vac lines then the box should lift out giving you access down the middle. A bit tight but it might do.

If the rubber is hard try softening it by heating it up with a hairdryer/blower, with a bit of lube they should slide. It's not too expensive getting new rubber - I got all eight pieces from porsche for £40 ($60) - well worth it. If you do move the legs you will need new gaskets as they do tear, again roughly £40 ($60) for all eight.

Did you get new O-rings, clips and spacers for your injector reinstall?

Cheers
Dave