Hey fellow XJ8 owners,

I bought the Elmscan 5 compact OBD11 scanner.

It pulled up the following codes:

P0300:Random/Multiple Cylinder Misfire Detected
P0301:Cylinder 1 Misfire Detected
P0308:Cylinder 8 Misfire Detected
P1316:Injector Circuit / IDM Codes Detected
P0333:Knock Sensor 2 Circuit High
P1111: Intake Air Temperature (IAT) Sensor Circuit Intermittent High Voltage

So my mechanic did all the "engine maintenance" spark plugs, oil change, MAF sensor, in February and this stopped the engine light from coming on.
But I still got the restricted performance yellow light.
Took it to the mechanic again, Oil in both left and right side spark plug.
He cleaned then up new spark plugs but still get the yellow light.

Any suggestions will be taking to mechanic in june for oil change?

Thanks in Advance

 

If you have oil in the plugs you have bigger problems, oil change in June won't fix it. You either have worn rings or damaged cylinders. Prepare for real money.

 

Was the oil just in the spark plugs wells or on the spark plugs tips at the gap? Huge difference!

 

if oil's in the sparkplug wells, it'll cause misfires - the usual fix is new camshaft cover seals and sparkplug boss seals.

 

Good question, He took out a spark plug from both sides and there was oil on the spark plugs, but I dont know if there was a puddle of oil in the wells!

 

Oil in the wells is a common cause of misfire and chances are that is the problem. As Sean said, new valve cover gaskets and seals will solve that problem.

Also, once the repair is made, the codes should be cleared. Then see which, if any, return after the repair.

Another thing to be aware of is that the descriptions coming off your Elmscan may not be accurate for a Jaguar XJ8.

For example, two of your codes have an incorrect descriptions for the XJ8. P1316 is excess emission due to misfiring. P1111 is not even a fault, itis just an indication that internal emission tests have passed.

So it appears your only issue is the misfires. It seams like the next logical step would be to replace the valve cover gaskets and seals, and clean the plugs.

You perhaps might also think about getting a new mechanic who know Jags