Are Boxsters always this unreliable
 

Can any one help i went out on Sunday for a ride in my 1999 2.5 Boxster. Was all good but about half way about 80 mile the revs on tick over went up to 1400 revs then another 60 mile they went up to 1700 revs after about 180 mile i got home and when i parked there was water running out of the over flow? i have only had it about 5 weeks and every time i take it out something else goes wrong. The only think still wrong with it now is the rev problem any ideas. Thanks

Not to be a jerk but are most 15 year old German sports cars any better?
Were there any trouble spots in your pre purchase inspection report?

No, well prepared and maintained Boxsters are often very reliable. Mine is.

If you want help to diagnose these problems we need a baseline:
5spd or Tip?
total mileage?
Mileage since last fluids change (motor and trans)?
Any recent work done?
What are "1500 revs on tick"? My car usually lives between 3k and 6k rpm.

Thanks its a 5 spd

Mileage 120k

Fluids 3000k ago

1500 is the revs it stays at when its on tickover.

It has a full service history and i have loads of paperwork for all the work done over the passed 15 years. Last owner had it for 7 years.

Thanks

On tick = idle.

Normal is 800 RPM; his Boxster is idling way too high at 1400-1700 RPM.

No idea.......

I'm also assuming the mileage is 120K kilometers = approx. 74.5K miles.

TO

No sorry its 120,000 miles

Grumpyfarmer, I'm in the USA, worse still, Texas, so you'll have to pardon my English. When I hear High idle, I'm thinking either vacuum leak, which would come with a check engine light, or an open throttle plate. Since you did not mention a CEL, I'm going with checking the position of the throttle plate. My first guess, since the idle is high but not in a steady state (1400,then 1700, then 1500), is something pushing the gas pedal? Maybe a floor mat? Barring that is the pedal sticking? Have you tried pulling the pedal back to lower the idle? If all of that fails you're in to opening up the engine compartment and fiddling with the throttle body to see if you can move the throttle plate to idle. If this is your primary transportation it's a big deal. But again as a farmer, you can fix any machinery in your sleep.

Hi jamesp

Had a look at the and the floor mat is not stuck under the peddle and it is not sticking.Looked at the engine and there is a little play in the throttle cable so there isn't any thing restricting it from the peddle to the throttle plate i take it that's whets at the other end.
Is there any way i can adjust it the engine end?

I have an e-throttle so no cable for me. On the play in the throttle cable, can that be there due to the throttle plate not fully returning to idle? Can you manually rotate the piece the cable attaches to towards its idle position? Adjusting something seems a little fishy. To me the symptoms make it seem more likely something is sticking rather than something needs adjusting.

I'd start by checking the idle control valve. It mounts to the throttle body. It might be gummed up and sticking. Remove and clean thoroughly. Be careful not to damage or lose the little gasket. Can't hurt to clean the MAF at the same time.

The idle control valve is #3 in the following throttle body diagram:

http://i1114.photobucket.com/albums/...pse7949a60.jpg

Here is a helpful link: http://pedrosgarage.com/Site_3/Clean_the_Throttle_Body.html

Do these cars have a EGR valve?

^No. Porsche uses secondary air injection system to reduce the NOx.

Thanks for your help i cleaned it all off as thstone said and i think it was the The idle control valve sticking. I idles at about 800 rpm so is good.Lets hope it down water dont start coming out of the overflow again. Thanks Again:)

Grumpy...
If coolant is coming from your overflow, replace the screwed cap on the resevoir.
The latest part number printed on the cap top should finish with ****04, if not replace as the seal is possibly leaking.