924Board.org

[Grenadiers]

Well, after fiddling with the nightmarish idle problem with zero results, thought I'd hoist the car up and take a look underneath. With my handy can of gum-out, I sprayed the bottom end near the turbo, and the idle went up! A few more shots out of the can and found that the lower rubber elbow on the control line seemed like the likely suspect. It looked good, pinched well, but I decided to remove it anyway.

Did some research and found Vaughn's write-up. Nasty job. After removing just about everything on top, was able to move the control line out of the way. I had previously purchased that elbow from Porsche along with 5 other elbows for upstairs. However, I didn't anticipate the upper hose connecting the line to the first runner of the air plenum. I had to cut that, and it's a reinforced hose. Can that be substituted for something a bit easier to find, like coolant hose? Or is there a PET number for it?

Also, to add to the idle problems, the front exhaust tube is broken at the flange. I had heard this before, but since the snow just left up here, hadn't a chance to take a look at it. And finally, the pop-off valve piston. Hence the pun! I read somewhere where that thing can rattle and it's due to a weak spring. I have that rattle, sounds like it's been coming from the rear muffler, which rattles when I kick it! However, I read that under no load, revving at idle, or on the road, is when it rattles, but not under turbo load which is exactly the conditions I have. Annoying, and the 'cure' was to stretch out the spring? The four bolts holding it in are sort of accessible, and am wondering if it's worth it to stretch that spring, and if that's the correct 'fix'. Thanks a bunch, Dave.
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'83 944 Track car.
'88 924S Track car.
'89 944 Turbo
2004 Winnebago Vectra monster RV
2012 Jeep Wrangler
2014 Kia Soul
2001 Ford F350 powerstroke

[Petrovich]

For the hose, reinforced vacuum hose like the kind used for brake booster will work, IF you can get it to bend appropriately. I don't have mine so I have no idea how it should look like. Mine is just a short run of abovementioned hose with a cap at the end.

Which exhaust tube broke off, the small one or the big one?
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1982 924 Turbo, now Lemon

[Grenadiers]

The big one, the front one, at the flange where it connects to the manifold. It broke before the oxygen sensor.
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'83 944 Track car.
'88 924S Track car.
'89 944 Turbo
2004 Winnebago Vectra monster RV
2012 Jeep Wrangler
2014 Kia Soul
2001 Ford F350 powerstroke

[Grenadiers]

Got the new elbow in place, idles much better. Now to weld up the crack in the exhaust tube for even better idle.
_________________
'83 944 Track car.
'88 924S Track car.
'89 944 Turbo
2004 Winnebago Vectra monster RV
2012 Jeep Wrangler
2014 Kia Soul
2001 Ford F350 powerstroke

[emoore924]

There's a gasket on either end of the piston that fails and can cause the rattle. It is in PET, # 53 and 58 in the diagram I think... a 930 part...