2000 boxter, rough idle but no CEL

[Janner]

Hi all,

New here ... have a 2000 Boxter (not an S) with about 85k miles, and had a dealer oil service in June 2013.

Last Friday, when coming home from an errand started the car, idled fine, made a phone call before leaving the parking lot, before the call ended the car started to idle rough and the rpm's dropped ... I turned off the engine, sat a few minutes then started the engine again ran kinda rough. I headed home. The whole time there was NO CHECK ENGINE LIGHT.

When I got home, about 1.5 miles, checked the dash again ... NO CEL ... and also checked the oil ... was low so added some ... the dash oil says FULL.

I started it yesterday and it idled rough so turned it off after about 10 seconds.

This morning I started the car, and it idled not quite so rough but the idle fluctuated between just over 500 rpm to about 1200 rpm ... eventually after about 60 seconds the car idled down and shut off on its own.

Again, at no point has the CEL light come on.

At the moment, have limited fund so any helpful advice would be most appreciated.

Thanks!
Janner

P.S. Could a cracked/leaking oil filler tube cause this problem and if yes, is this something I can do myself or must I take it to a garage?

[sb01box]

I would do

Check for any vacuum leaks

With engine at idle, see if you can remove the oil filler cap - test for bad AOS hard to remove is a bad sigh. Search AOS.....

When is the last time the Mass air sensor was cleaned?

You did not state the volume of oil added, but you should not have to add any if seviced in June. I usually wait good 10 minutes after turning the car off before checking oil.. Overfill is bad

[Janner]

Thanks for the reply.

I will try the 'remove filler cap while running today'.

I don't know the answer to the MAS, the car was purchased about a year ago. Supposedly it had all service done by the Porsche Dealer in Naples at the required times and intervals, at least thats what the records say.

The oil added was about two quarts, but I may have overfilled the oil.

Janner

[sb01box]

two quarts .... something is grossly wrong.

if overfilled, this is bad.
check the oil level using the dipstick before running the engine
rI would drain the excess before starting the engine.