Vacuum line replacement

[dhill]

So how hard is it to check all/most of the vacuum lines with the engine in the car? A high idle has me wondering on my '82 SC. Any particular lines that tend to go bad?

[steely]

If you dropped the engine, you could certainly inspect them all, but if not, you can use unlit propane and test accessible spots with the engine running. (include area around intake gaskets - not just lines).

The pipe adapter in front of the engine (on mine) was cracked. (pic below) The smaller Dia ones I just replaced. The larger one to the brake booster (if you have power brakes) is easy to test, a little more difficult to replace. Ref post: vacuum leak you probably didn't ever think of

Two things I'd mention would be to do a search on "vacuum" and "leak", and last, I thought a leak would cause a drop in idle (like when you remove your oil cap). Anyway, HTH.

[Neel]

If you access to a smoke machine, that's your best bet to find even the smallest leak..

[euro911sc]

Just replace them all... it is cheap. $10/meter at your local VW dealer gets you the correct cloth covered line. Do one line at a time so you dont get mixed up.

-Michael

[dhill]

How many different sizes are there?

[tevake]

There do seem to be different sizes, I'm trying to find a kit with all the lines made to length. Or the lengths of each size of hose needed to make them up??
Any leads?

[steely]

Well, there aren't a whole lot of different sizes, but I would start with the smaller diameter ones first as these are the "easiest" - you can get small vac lines at your FLAPS (local auto parts store).
If you can get a PET catalog, that will list all of the vac lines.

That said, a wholesale replacement is easier said than done - refer to the link I gave you for the vacuum brake line as a tougher example. I think I listed 2 common prob areas.

Also, again, I would verify that a vacuum issue is the cause of your high idle. Perhaps someone else could chime in as to whether the oil cap removal test is a good check for an '82 SC (remove the oil cap and see if the revs drop = decent system vac).

Here is a jpg of the 3.2 vac line decal fyi.
hth

[T77911S]

thats the wrong engine guys, unless you k now something i dont, he has CIS.

high idle with CIS is likely the aux air regulator (AAR). it can stick, or go bad, or the 12v to it may not be there. the 12v is the easiest check.

its a good idea to just reseal the whole system. but, it involves removing the CIS. the major things you want to replace are the intake gaskets, the rubber boots on the runners, injector sleeves and Orings. you also want to replace the 2 hoses to the oil tank and the gasket on the oil cap. they are often over looked.
once all the rubber is replaced, you will have to have the mixture checked.