Sorry for lack of technical expertise and poor communication skills.

My jaguar xf has rpm fluctuation problem,
The RPM drops to 500 and jumps to 1200 RPM. some times it become stable like normal.

1) The mechanic clean the Fir flow sensor and disconnect battery terminal, issue fix for 2 weeks and reappeared.
2) after that I clean the throttle body by throttle clean spray only and RPM become stable.
but now its again appearing.

please help and suggest any corrective action.

 

Vac line leak?
Check your intake for cracks?
No codes?

 

Thank you for your reply!
The mechanic only check from top and no leak or crack found.
Also he connect scanner and no code or error found.
Also he recommended me to replace throttle body, but I am confused that if throttle body is faulty than why become normal after cleaning. And it start with minor fluctuation than keep on getting worse until it fluctuates from 500 to 1200 RPM. And sometimes it becomes totally ok and then reappears.

Need your kind support. Thank you.

 

Honestly, it really is troubling that it's working for a while after cleaning. Are you using oiled air filters? K&N or something? If those have too much oil on them, they can get your MAF sensor dirty time and again. You could try cleaning the MAF sensors and replacing your air filters with stock paper, if this is the case.

 

Sounds like the mechanic simply knows too little. Find someone with a clue about modern cars (since about 1986). They have computers....

 

Thanks for your reply.
i am using paper filters and clean them along with MAF Sensor.
...
Today i make complete computer scan and test and no issue found even coil and sensors are working fine. The new technician recommend me to change spark plugs.

I will replace them in coming weekend and hope it will fix the issue.

i will also update the results.. please recommend me anything if it can help me.
Thank you!

 

Thanks for your reply.

your are correct. the technician i was dealing with was not trained on jaguar.
The new technician recommend me to change spark plugs, as all tests and scans are normal.

I will replace them in coming weekend and hope it will fix the issue.

Many Thanks!

 

Plugs issues that would cause the RPM surging you speak of would throw a code. I would look at the throttle position sensor FIRST if no codes are showing and all else is checking ok, as there is A LOT of labor involved in changing the plugs (Yes I did mine https://www.jaguarforums.com/forum/x...change-145292/).

 

Thank you Mr. n8ertot, Mr. JagV8 , Mr. Bigg Will for your help.

After replacing Spark plugs, the RPM is stable at 650. I hope it will remain stable.

once again thank you so much for your support!