Got a 2004 Jaguar S-Type with 85,000. The car just recently started having idling problems and runs horrible until the motor warms up. The engine idles up and down when first started. Ran a scanner and got P0300, P0301, P0302, P0303, P0305, P0306, P1316, P0420, P1111. I know that the 300's are cylinder misfires and know the definition of the codes but have no idea what it means. Not an engine person but open to suggestions of possible causes.

 

Please fill in car details as below!

I'm guessing 3.0

Could be any of a few things but an air leak would be #1 suspect. Look for threads on PCV hose / PCV elbow. May be in the FAQs.

Could also be intake gaskets (again, Search) - sealing better as things heat up (but they need to seal all the time LOL).

If you can watch live data, watch LTFT (long term fuel trims) on each bank at idle and again at about 2500rpm. Fairly positive at idle but reducing at 2500rpm is a fairly sure sign of an air leak.

 

If it's a 2004 3.0, there is no PCV elbow like the older cars. It might be IMT-O rings, but

the p1316 code is misfire and excess emission. The possible causes are the same as the p0300 code which are:
Fuel contaminated
Fuel injector(s) blocked or leaking
Ignition secondary circuit breakdown
(coils, spark plugs)
Fuel pressure low
Cylinder compression low
Broken valve spring(s)
CKPS circuit fault (CKPS DTCs also flagged)
Fuel injector(s) circuit fault(s)
(Injector DTCs also flagged)
Ignition coil primary circuit fault(s)
(Ignition coil DTCs also flagged)

If it was just a vac leak, the misfires usually come with a p0170 / p0171 lean code. This thing sounds like it's not firing on all cylinders or that an injector is bad.

Take care,

George

 

In the 3.0 V6, the first place to look for the root cause of misfires would be the two Intake Manifold Tuner Valve O-rings, and then a potential crack in or misfitting of your air filter housing. Lousy coils caused many misfiring issues with the early S-Types, so Jaguar tried different coil suppliers and designs as the years passed and by the 2005 model year, faulty coils are not nearly the problem that they used to be. Vacuum leaks are always a potential problem, particularly as the rubber hoses age. The orafices in the fuel injectors in these cars are nearly microscopic and have a tendency to clog after as few as 30,000 miles, so that's another potential cause for misfires....

Our 2005 S-Type developed misfire issues in cylinder 3 in the September/October 2009 timeframe. New IMT O-rings and a new air filter housing cured that problem in our car. No misfires since....

Keep us posted as you take the ideas presented in this thread and run with them....

 

Misfires on what looks like all cylinders ... and a cat code ....

So far, some guesses. Read the LTFTs and you'll be able to rule lots of things in or out.

If you can do it, look at O2 waveforms and responses.

 

Yeah I dont know too much about working on these things but I keep getting advice about the air leak more than anything. If it helps narrow it down. I just recently erased all the codes and the first start up the car started to lunge foward when I let off the brake in drive and reverse.

 

Got the problem fixed hopefully. Located a cracked rubber fitting that attached to a plastic hose on top of the engine. Replaced rubber fitting and havent had problems yet. Appreciate all the help and advised that led to this being a dollar fix.

 

Solved all the problems except its still popping P1000 and P0420.

 

Search for P1000 and read

Same data leads to P0420 and what can cause it.