My 08 xjl idles rough at cold start then smoothes out after a few minutes ??? What y'all think
SHOWS CHECK ENGINE LIGHT

 

I think your in the wrong forum...but even us dinosaur X308'ers can throw some mud at it. I say its your MAF or O2. Pull the codes, it'll tell ya.

 

The starting point of any diagnosis is to plug a scanner in and record the OBD codes and then clear them. Then drive the vehicle until the Check Engine Light comes back on and plug in and record those codes. The new codes are the correct ones for the current problem. Post those and we can help you sort it out.

 

Cold start rough idle smoothes out after warm up check engine light on ...
Replaced mass flow sensor , did smoke test , etc what now ? Gaskets ?

 

Already replaced the mass flow sensor also smoke tested and still throwing check engine light ...

 

Hi warsaw,

I have moved your thread from the forum for the X308 to the forum for the X358, which is the Jaguar factory project code for your 2008 XJ8L. I also took the liberty of adding "Rough Idle" to your title to help clarify the nature of your thread.

As you've already been advised, without knowing the specific diagnostic trouble codes (DTCs) we can only guess as to the possible causes of your rough idle at cold starts. Most auto parts stores will scan the Powertrain DTCs for free. Write them down exactly as they appear (they'll have the letter P as the prefix, usually followed by four numbers), and we'll try to help.

Cheers,

Don

 

Read the codes.

 

Been reading codes for 4 weeks folks and problem continues to come back appears now to call for gaskets

 

been reading codes for weeks now folks problem continues

 

What were the codes you read?

 

Running lean bk 1-2

 

running lean bk 1-2

 

Ok however what were the actual codes you read please?

 

P0171 and P0174 or some other codes?

We'd love to try to help, but you're not trying very hard to help us help you.

Please give us all the specifics you can. If you've been reading codes for week, what are all the codes you've read?

Don

 

Po171

 

DTC Summaries

 

And do the usual fuel trim checks.

 

Answered in your other thread about the same issue
https://www.jaguarforums.com/forum/x...-start-200504/

 

warsaw,

Thanks to JagV8's heads-up I have merged your two separate threads. Please do not start multiple threads on the same topic because it leads to confusion and is a violation of forum rules.

Cheers,

Don