In my 2001 XKR I continue to get the engine light with the following readings:

P0300 - Random engine misfire
P0303 - Misfire #3 plug
P0305 - Misfire #5 plug
P1316 - Misfire too often to pass emissions test.

After clearing the codes it seems to only happen againwhen I really "get on it" to pass or freeway entry. Car is runningfine. Any suggestions?

 

How many miles on the plugs?

 

61,000

 

swap coil 3,5 to 4,6 and see if it changes.. also are you chain tensioners noisy?

 

I'll have to check out the coil change. Are they marked? I have no idea which one is which.

Brand new(upgraded) upper and lower chain tensioners.

 

Morning Lew.

Cylinders are right bank (passenger side) A1 thru A4, Left side is B1 thru B4 or 5 - 8. P0303 is A3 or the third cylinder back from the front on the right side. Jag_Genius is saying to swap the coil pack from the third / fourth cylinders. P0305 is B1 (5) or the front cylinder on left side. Swap it with the next one back (6). Removing the coil covers and coil packs is easy; just a few 8mm bolts. Remove the electrical connectors on the coil packs before removing bolts. While I had coils off I would check plugs. While replacement interval is 100k miles, a lot of us change them a little more frequently.

In fact, since you are going to have both covers off and 4 coil packs off I would just change the plugs.

You might check eBay for a copy of JTIS, the complete Jaguar service manual on one CD. For a few dollars you can save thousands at the dealer.

Another thought: did this problem exist before tensioners?

 

I will be headed to FL in the morning, so won't have time to check it until I get back. I'll see how it runs on this trip. I plan to run a can of BG 44K injector cleaner on the trip and see if it clears up. What plugs do you recommend? I think NGK plugs were OEM issue, but there are many new plugs out today, including ones from NGK. I heard it was best to just replace them with OEM plugs rather than any of the new ones. I also read that changing all the coil packs was a good idea if any are giving trouble and that 01 were some of the worst ones. How much do coil packs cost? I have the JTIS and it is pretty good at telling you how to get at something, but doesn't do much for diagnosing anything. I remember the old Helm manuals took you through step by step diagnosis, but I guess OBD2 replaced that. I bought the car in January, so I can't really say if this was a problem before the tensioners were replaced, but I only saw it that way from my standpoint. The tensioners were not giving me a problem, but I had them replaced as a preventative measure. Pete, from Coventry West did the replacement for me. He has done dozens of replacements so I really trust him on this. He has also done some tensioner replacements for friends.

 

After reading all the opinions I just replaced with the Jaguar plugs.Don't even know manufacturer, said Jaguar on box. Check on internet or Coventry West for best prices. Coil packs at the dealer are $160. . . . each. Saw a set go for $110(used) on eBay.

Within the JTIS in the tool bar is an icon that says 'DTC'. That is the list of codes you referred to. Across from the code is a list of probable causes. Not perfect but a place to start.

 

7mm bolts

 

Sorry!

 

Thanks for the tip in JTIS.

I have bought parts from Davis Automotive Group at very good prices. They have new coils for $106/ea, so I guess that is a good price.

https://www.trademotion.com/partloca...mp;catalogid=2

 

Well, I'm in Fl now. Drove 330 miles averaging 75mph. When I first started out, It started to get the check engine light flashing and reduced performance on mostly down hill runs with the cruise set. As it started to level out and acceleration was called, the light went out and the reduced performance went out. I noticed no change in drivability or performance. After about 100 miles I no longer got any errors. I did add the BG 44K at the beginning of the trip. I will hook up the OBD2 tomorrow and see if it left any codes. Very strange.

 

Well, I don't know what to think. Return trip from FL with no problems. Just made a trip to Rome, GA and still no problems. I guess I can call it "fixed"!