s4 clicking and high idle

[cronin]

Hello,
My 87 s4 has a clicking noise that speeds up as I accelerate, also the car idles very high and when I shift it into park it will idle at about 2000rpm.
any suggestions?
Thanks.

[cronin]

anybody?

[MPDano]

Sorry, I don't have a later car so i cannot give much input. Did you check all your vacuum lines? Leaks?

[cronin]

Thanks for the suggestion, Is there a walkthrough as to how one would do this? I am not terribly familiar with the mechanics of a car but am eager to learn.
Thanks.

[MPDano]

Well, time to get your hands dirty. Look for all vacuum hoses and look at their condition. Old and cracked will leak. See if they are all plugged into something, they will leak if they get pulled out by accident. There are diagrams in some posts on here, try doing a search on this site. It get's very hot under the hood so your gonna have to start replacing old hard and brittle hoses left and right.

[JhwShark]

Not my year either...Search the board for posts on checking vacum as well as fuel injection (the clicking may be the sound of the fule injectors??? emphasis on may)

There are a lot of posts on lots of what may be up...It all depends on where to start the evaluation.

Are you a novice car mechanic, these beasts require some core skills to keep in top running condition??

You will also find a lot of help; however, you need to be very clear in your inquiry with what specifically is occuring, what work you know has been done, and what skills you can bring to the table.
Jon

adding: check some of the tips from sites listed in a very recent posts,there a some good informational posts out there. Once you've read some you will really understand the SCOPE of 928 maintenance.

Leo is right get dirty, get into the rig...take a lot of pictures along your exploration they will come in handy for reassembly as well as when asking for help.

[cronin]

Excellent stuff, thanks guys ill take a look this weekend.

[JhwShark]

Update your sig to show your car year, US or ROW...ALso list the general geographic area you are in. Some folks may even come over to help or invite you to a work session...

[tisilrad]

First check the main vacuum line feeding from the intake manifold on the drivers side...this feeds to a venturi tube that also connects to a hose from the intake hose under the Mass airflow sensor. Next check the splitter and hoses around the brake master cylinder..the splitter is known for dry rotting and leaking. The line feeding the brake booster directly is large and a leak will cause an engine high idle. The other vacuum lines come from the intake to another splitter at the back of the engine, feeding the fuel pressure regulators and dampers(and automatic transmission if you have one) these lines and splitter also need to be checked. There are two lines feeing into the firewall to the HVAC control system under the dash where a primary vacuum signal log feeds the actuators for the hvac system controls..these are prone to leaking and could possibly be heard if leaking..if all of your positions work for your Air/heater then these are probably not leaking...though the actuators are prone to failure(at least in my case). The vacuum resivoir also is prone to cracking and leaking.These can be checked by listening for the tiny whistle. (Please note that an old method of checking these is to spray starting fluid on each line and if it causes an increase in engine speed , then it was leaking. PLEASE DO NOT DO THIS..IT IS VERY DANGEROUS, EVEN A TINY BREACH OF THE INITION SYSTEM WILL RESULT IN A FIREBALL AND IN GENERAL IS NOT GOOD FOR YOU OR YOUR CAR!!!.. I had to mention that) The best way to check the lines and general system would be to purchase a mighty vac vacuum pump(a very good investment) and isolate each hose/line from the intake and see if it holds vacuum..you can check each indivdual line this way..note that the vac reservoir will require a lot of pumping to draw down a vacuum so be patient. There are two lines coming from under the intake that are hard to check, if you want you can disconnect them and see if they are drawing strong vacuum while the engine is running but this wll affect the engine idle or possibly stall it...one feeds the fuel regulator splitter mentioed earlier and the other the tank venting valve(passenger side under the coolant tank) It would be best to get a diagram and trace each line but this is a genaral overview..the internet is rich in materal on this matter so do a little research and you should find any info you need.
As for the ticking sound i would need more info as to possible location etc.

[cronin]

Update,
Well I think I may have nailed it down thanks to all the great information. It turns out when I was installing new spark plugs last year I actually ripped out a small hose that connects the engine to a unit in the back left of the engine compartment, it is clearly a vaccum hose of somekind, when I put my finger over the hold that the hose should have feed into the there is a noticable difference in how the car runs. I will reattached it tonight and hopefully that will fix my problem.
Thanks again guys.