My 04 XJ started acting up again.

When it's warm, especially if I've driven in heavy traffic, when I stop at a traffic light the idle RPM would go up and down and eventually go too low so the engine starts shaking - it almost stalled on a few occasions. Then it would go up again, up-down a few times and again go to low.

I get no codes, no warning messages - none.

I tried stopping the AC, shifting to Neutral, the roughness of the idle is not so severe, but it still happens.

The dealer also sounded puzzled on the phone, having a diag done tomorrow.

Any suggestions, what to look for?

 

Most likely the throttle body. (Throttle position sensor)

 

or possibly an air leak, brutal referred to it as a closed/sealed system, I think...something like that, I tried to remove my oil filler cap when the car was idling once, and it staggered and almost stalled. I asked the question and he confirmed it. I'm not good at describing the principle nor giving you any other places to look for a possible breach, sorry. It is, however, possibly relevant as a diagnostic event.

 

Veff

Do let us know how this sorts out. I sounds interesting.

 

Yesterday evening, when I was about to park, I got "engine system failure" then "dsc failure". So it might be the throttle body. It's in the dealer now, we'll see what they say.

 

Happy to report it went better than expected. The tech found misfire codes on all cilynders (altough there was no check engine light). There was a TSB related to these codes and it called for a new inlet clamp (XR849658) and ECU update. Total right under $200.

The car rus stable when idling on traffic lights now. Before the RPM would always go up and down by 50 or so, now it's steady. Crossing fingers this was it.

The service report does not say what codes they found or what TSB they refered to.

 

sounds right for your symptoms...inlet clamp huh, that thing that clamps the air pipe rubber piece to the throttle body? That should have been obvious, I would think.

 

replaced timing chain and tensioner when restarted car back up had a message code of cat system fault and open boot

 

Hi Ron,

Welcome to the forum! You may have more luck generating responses if you start a new thread with a subject heading that describes your specific issues, rather than piggybacking on this thread which is on a different subject. That way, folks who have had your symptoms will be more likely to respond.

Cheers,

Don

 

I had similar issues but my resolution was a bad PCV valve. If I had the AC it would cause the engine to sputter and sometimes die/stall. If I got to the point of steering wheel lock backing up or turning in my driveway, it would again stall.

13 year 2006 XJ8 with about 113k on it; so not the worst thing in the world. This thread was very helpful in leading me down the path to the correct diagnosis.

This forum in general is also helpful at other gremlins I've had. A mysterious DSC light or cruise control not available light tied back to a bad battery. Replaced with an AGM battery and again no issues.

Hoping that adding my issues to the mix helps someone else out with a diagnosis.

Good luck to all. I may have to give this beauty up in a couple years; even after all these years, it still puts a silly grin on my face. Hopefully I can find it a good next owner when the time comes.