Hey everyone looking for some help figuring out an issue. My 03 XJ8 will run fine, then it looses power, and the reduced performance warning comes up. This will happen at any time while driving or at a stop. It will start fine then seconds later it may, or may not, run rough. It is intermittent and seems,at times, to not fire on all 8 cylinders but just 7 or 6. The codes show that almost every cylinder has misfired. They also show that the camshaft position sensor is searching for a signal. I've checked wires and fuses but to no avail. Any assistance would be greatly appreciated.

 

Have you checked the MAF sensor and when was the last time you did your plugs? Also check the air filter ...and ventilator hose for blockage to the air tube, ...yes its happened before here.

 

Oil leaking around cam covers and soaking cam sensor? And plugs, oil soaked too. A little cleaner; clean the MAF sensor; clean throttle bore and plate; check for air leaks from air filter to throttle body; run a can of fuel system cleaner. You need to get the OBDII codes read: any chain auto parts store or buy your own reader. Keep the forum informed, please.

It seems to me we are seeing a lot of cam and crankshaft sensor issues within the last year or so -- the 308s are getting older . . .

 

Ok all. I just got back from a test drive and I think this may have done it. I picked up a can of MAF cleaner, and tore down the air breather assembly. I cleaned the MAF sensor, sprayed down the inside of the breather tube, and the top of the air intake. It started just fine. No issues. Went for a drive in town and on the highway. It seemed to back to its old self. I hooked up the obd2 scanner and cleared the old codes. Started her back up and no check engine light. Yay!!!

Thank you for the assistance! I would never have thought that something so simple would cause such an issue. I'll keep you posted if anything changes.

 

There's no visible oil leaking anywhere. Old plugs looked like old plugs. No presence of oil in the cylinder.

 

Most codes need 2 warm ups AND many need the OBD monitors to be happy before they can flag.

You can check for the latter by making sure you have P1111 (not P1000) pending.

 

Get the breather valve(pcv) routed OUT of the intake tract! Route it to atmosphere. Don't need to be breathing hot, oily air and getting everything all carboned up from it. First thng I do to a newly acquired vehicle.
This nonsense is an EPA/EU5 mandate that is NOT good for your engine. You want to breath cool, dry air into your combustion chamber. Not hot, oily air.
Stick a bore scope in your spark plug holes and look at the top of your pistons. Not a pretty sight!.

 

That is against the law in most states: try to remember there are 49 other states besides Iowa.