Hey Lads,

My GF bought a 2018 F-Pace this past weekend. She is extremely happy with it so far and I am happy for her. Nice to keep it in the family.
My XK8 has nearly hit 170k on the clock and I still love the car. It needs some love here soon and this is the perfect timing (pardon the pun) to get some work done on it. Her old vehicle is a 2017 Jeep Compass and since she plans to sell it privately, I have access to it for a while. She is in no hurry, so this allows me to lay up the XK8 for a bit to do some more in-depth work on it. So, what does this all have to do with P1316 you might ask? Well, it's a theory - or maybe it isn't but it is in my head anyway.

At the moment, I have codes P1316, P300, 303, 305, 307. I think those last numbers are right? Anyway, it relates to misfires detected on cylinders 3,5,7
I have done the basic troubleshooting on this issue having swapped out both plugs and coils on those 3 cylinders to see if the problem persists. I have a full set of coils since I replaced them all some time ago and some of them were new NGK coils. Good enough to verify this issue. The swaps did not make any difference and the same codes remain. Also smoked the engine multiple times, cleaned the MAF, checked for frayed, cracked or burnt wiring - all negative. So, I started to do a little deduction on what the possible cause could be here.

I have mentioned on several occasions that my engine chatters when cold on start-up. Since I have a 2003 model with the updated metal tensioners, I just chalked it up to oil pressure check valves somewhere in the system. Others have reported the same and after only a second or so, the chatter stops, and the car runs fine. It has done this ever since I purchased the car nearly 5 years ago. Using some deduction and pointing the finger at this as being the possible issue I am having - I have come up with these thoughts.

- The tensioners are obviously there to keep the chains tight and hence keep the valve train aligned to the crank.
- The tensioners are kept taught using engine oil pressure and a check valve somewhere in there is supposed to maintain the pressure on the tensioners when the engine is turned off.
- Should the oil pressure bleed off, the tensioner releases the pressure on the secondary timing chains and allows the assembly to go slack. Once the engine is restarted, the pressure comes back but not immediately so there is a window of time whereby the cams are not truly sync'd with the crank.
- I believe there is a window of timing error that the ECU would allow but once the timing goes off by an amount greater than this, the ECU detects it as misfire.
- Since I have had this since I bought the car and certainly the PO experienced the same issue for some time, it means that the cam chains and tensioners have endured this slacking and tightening for hundreds and hundreds of cycles. That chatter is timing chains slapping against the guides I suspect until the pressure makes everything solid in there.

So having said all of that, I believe that replacing the secondary timing chains, guides and tensioners could possibly be the fix for a nearly full bank misfire detection. The codes all came at once, so it wasn't like there was a slow degradation to this point and since nothing else I have tried has had any effect, it seems completely plausible to me based on the pre-existing chatter I have. It could certainly be something else too and I do have some mild air leaks in the engine. The short-term fuel adjustment on bank 2 runs about 12% more fuel on average but bank 1 never goes more than 2-3% on added fuel. Since the misfire codes are all on bank 1, it makes sense that this wouldn't be a contributing factor.

One more thing - The engine has never exhibited any signs of misfire to me. It has - and always has - started and run / idled smoothly. So, I deduce that since I believe that misfire detection is usually done immediately on engine start, this is the time when the chains are slack. I put all of this down for future reference for others. I am going to go for it anyway and replace the secondary tensioner and chain assembly because - why not? While I am in there, I will inspect the primary chain and tensioner assemblies to see if they also need to be addressed or may even be a contributor to all of this. If I am successful in the job, it will point a finger at this as being a problem for others that may be experiencing full bank - or nearly full bank misfire codes.
Will now do some research on the physical aspects of doing the work. I have read it is not that big a task to only replace the secondaries but would appreciate the list of tools needed to do the job outside of the regular shop tools. Would also like to know where the parts are routinely sourced?

Thanks in advance and now let's see if it makes a difference

 

My first thought is that your timing chain and or tensioners is not the problem. But I have mistaken once before........
The upper tensioners is a rather easy job, with no need for special tools.
If you go further and want to change out everything, chains, guides, lower tensioners etc. Then you need some special tools.
First of all tools for the lower pulley: Crankshaft pulley tool
And timing tools: Engine timing tool
(this are just examples so you get an idea of what you need)
I changed it all by my self on my 2000 XKR last year, so if you have worked on engines before it is absolutely doable.
When it comes to your misfire I would have checked the injectors and maybe ECU before I went further.
You can take off your cam covers and check the timing of the cam axles if you are convinced that the problem lays there.

 

Hello,
I have the exact same problem with my 2003 XJR that I purchased a few months ago. It has a clacking noise that is not apparent in neutral and park but when I put it in gear, the noise starts. After warm up it makes no noise. I have just changed the spark plugs and knock sensors and a number of other parts and the car runs great. No misfiring or stumbling at idle or at speed when cold or warm that I can detect. Never the less, I keep getting these check engine lights with the P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, & P1316 codes each time after about 30 to 90 miles of driving on the interstate or regular roads. I am certain the car did not miss fire when I got the codes two days ago. I was sitting at a red light, had started the car a few minutes earlier, and drove less than a mile. It popped up while I was looking at the dash as I was hoping to get at least 50 miles on the car so I could get it inspected and get a license tag. Got to get it repaired not just for the tag but because I cannot have a CEL problem in any of my cars.
The car had these same the codes when I purchased the it. It also had a knock sensor warning so I figured if I changed those, the codes would be gone. Well, no knock sensor problems but I can't shake the other codes.

Any advice would be most welcome! Thanks a bunch!

 

The tool links are much appreciated thank you!
As an update to the previous list, my fuel injectors are all fairly fresh, rebuilt and flow tested units I bought as a set last year. Everything is always suspect of course but I tend to back up macro problems to a single source. I would have to assume - maybe wrongly - that I have injector issues down almost a full bank of cylinders. Anything is possible but is it likely?
Having said that, I do plan to check the timing while the engine is cold because this is when I suspect the secondary tensioners will have lost oil pressure and relaxed on the chains. What I hope to find is a set of cams slightly rotated out of time when this occurs so fingers crossed on that. If I find that the timing is dead on even in that cold state, it still wouldn't hurt to change out those assemblies in an effort to maybe stumble on why the engine chatters on cold startup anyway. A number of other 4.2L guys have reported similar issues with that and the current intel says it is because a check-valve somewhere is not maintaining oil pressure after the engine is shut down for a while. No one however, seems to be able to identify where that check valve lives? So this is a bit of a dual quest and since I have the use of another vehicle for a while, I might as well go for it now. The downside is that I end up with new secondary chains and tensioners in the end.

 

Honestly, I do not think our issues are the same at all.
Even though you are getting a bunch of misfire codes, your symptoms happen in a manner that is quite different to mine.
By all means, follow along and maybe we will both get lucky but I suspect that you have other issues going on in there that may or may not be related to mine. Having misfire codes across the entire engine is a much larger macro issue than the one I am dealing with

 

What brand oil filter is currently fitted?

 

do a relative compression test

widebands good? you can get dubious misfire codes on cold start

 

Sure sounds like the secondary cam chain has jumped a tooth (maybe in both cases). I'm no expert, but I believe there was a period where the 1st generation secondary cam chain tensioners (what a mouthful) were replaced by the 2nd gen tensioners, which weren't much better. The 3rd generation tensioners used spring tension to keep them from going slack, instead of oil pressure. I remember doing mine (on a VDP) and they have a little pin you pull after you get them in there. Pulling a cam cover will tell.