As of late I have noticed my 2004 Jaguar XJ8 running rough for approximately 30 seconds on hot starts. Also, the RPM's will "surge" slightly until the car warms up (after approximately 15-20 mins of driving) and there is slight hesitation.

Today a fault code of P1316 was detected after the check engine light was triggered. There are numerous theories regarding this code on the forum, including a weak battery. Is there a true "magic bullet" with this code in pinpointing/diagnosing the exact root of the problem?

Just wanted to see if there was anything I was missing or something imminent looming in the darkness waiting to cost me thousands!

Thanks in advance to all.

 

Indeed, the P1316 code, at least on my '02 DTChart, provides a complete grocery list of issues from compression to ignition to fuel. It also says that the code will not be set without a corresponding P030x code for an individual or multiple cylinders. Got codes?

As far as rough idle on start up a quick shot of throttle body cleaner may well address that. The critical area to clean is where the butterfly valve meets the TB throat. All else is just being neat.

Here is the diagnosis list if that helps any.

 

Thank you sir for your quick reply on the matter.

The only other code that was triggered was the "all clear" P1111.

The P1316 showed multiple misfires on cylinders 1,3,5 and I do believe 6. 1,3 and 5 I am certain.

I drove the car home after the diagnosis and it did the same thing briefly after a hot start while pulling into my garage.

One thing to note: I have now had a Mina gallery cold air intake installed on the car for about one year. Could this be an issue?

Lastly, is it safe to drive the car with this issue occurring?

Thanks so much once again.

 

For 2004-2005 4.2L engines, P1316 means misfires at a rate that WILL cause excessive emissions.

That is opposed to P1313 and P1314 which are misfires severe enough to cause catalyst damage on Bank 1 or Bank 2 respectively.

Cheers,

 

Many thanks on that code info! Dropped by to see my Jag mechanic yesterday just for a checkup and we've attributed it to a bad tank of fuel. Everything seems to be fine at the moment, we've cleared the codes and so far it has not thrown another check engine light at me.

Will keep going for now!

 

What exactly do you mean by bad fuel? Seems unlikely that fuel caused a misfire a knock yes a misfire I do not see how

 

DrGianni,

Welcome to the Jaguar Forums. It's great to have you with us.

You have made your first post in a thread that has no activity since 2102. If you have a question related to your own Jaguar, I suggest you start your own thread, but only after you visit the https://www.jaguarforums.com/forum/n...-intro-must-5/ and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don