Jfarrell8 while I cannot point to the specific thread and wiil attach a quote from another member.regarding the need to use the proper oil and that the NA V8 is the most critical engine that requires the recommended oil as you have dual profile cam lobes and that there are narrow passages used by the oil to "select" the proper cam lobe profile. In short, I am hoping your diagnosis is correct and that there is no residue buildup in some of these passages that would result in your current issue. Best of luck and if you haven't switched to the newer recommended SAE 0W-20 meeting Jaguar Land Rover specification STJLR.51.51.22. it is highly recommended.



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@XJsss yeah absolutely i did some research on different oil additives. And it does seem strict on oil type! So still learning i appreciate your responses. My plan For today is to call the place i bought the car and ask what oil they use. It could have been an off brand type I know my mercedes in the past were oil finicky i shouldnt have guessed otherwise with this car either. Now a side note if the CPS solenoid was work out or getting ready to fail could it allow oil to seep back when you turn the car off because the oil would be hot and viscous making something knock

 

And after reading the literature you sent about the CPS the one article explained something about a malfunctioning cps solenoid and high load vs light load i have the symptoms of ill response or fluttery idle that does lead me to believe im having a cps solenoid issue but why wouldnt it throw a code?

 

I Can't answer that, maybe someone with more knowledgeable can answer that as I have a supercharged version of the engine.

 

@XJsss no problem thank you for your help. Be back with updates of my noise on the N/A 5.0

 

Hey @Jfarrell8 , any update? My 2011 XJ N/A V8 with 74,000 miles is doing the same thing.

 

hello!! I hope this reaches you well. So i have no updates but plan on (once this covid **** cools down) talking to the dealership that worked on the car about whether the timing chain circuit has been repaired or replaced at any point. After that, i have a euro mech. That wants to look the car over and see if he has any ideas. I will do that soon, beings that its my primary i gotta get my bikes out of storage so im mobile.

 

Hey @Jfarrell8 , any update on this noise diagnosis? I've been trying to track down the same noise for some time now.

Thanks!

 

hey so i have learned to live with the noise, until something catastrophic happens or a code is thrown. The noise does disappear but the idle can be wonky sometimes. I have checked my timing chain throw the fill hole on the drivers side cam cover and the chain does have some slack. I have come to think that the timing chain tensioners seals have failed and as the oil heats up its more viscous leading the timing chain tensioners to have low pressure allowing the chain tensioners to get slapped causing the knock or hard tap noise. The other thing i suppose could be an issue is maybe the high pressure fuel injector mechanism could be tapping when the heat is up and the tolerances are different but as the oil cools them or however that works the noise goes away. I am leaning towards the latter, but if you come up with anything let us know because to this day of extensive research still nothing but people saying they have had engines replaced and waranty work done. Id take my motor apart to figure it out but at 180k id rather just save up for another motor i can completely fix up outside of the car.

 

And as a side note i do drive my car hard and she still drives perfect and pulls very hard! So i feel confident in the motor even with the dreadfully mysterious knock

 

Definitely worth considering the frequency when diagnosing noises.

Main bearings knock at crank frequency. Big and small ends, usually double crank frequency. Tappets, cams, etc, half crank frequency. Anything associated with exhaust - resonance, blowing etc, half crank frequency (assuming only one cylinder affected).

If not sure, you can get cheap optical frequency meters on Ebay. Pretty handy anyway.

 

thats honestly a great idea to atleast narrow down the engine function it could be associated with, i have found on the drivers side exhaust the knock resonates with the pulse so thatd be half crank thus enforcing a timing system issue?

 

I hear a lot about using the correct oil in these v8 engines, however I can say that using an engine oil of the “wrong” type will not cause immediate self destruction of the bottom end, using the correct oil is about, among other things, fuel economy, performance, and long term engine protection, when you look at any engine design not much is different and the way the oil works in the various components is the same, so using the correct viscosity is important and using an oil with properties that the manufacturer recommends should result in good long term protection, however using an oil with the wrong viscosity isn’t going to harm short term, unless it’s really thick. The really important thing is frequency of oil changes, many of the oils are developed to stretch the oil service intervals, this is ok if the car is driven in a particular way, say start up and drive 30 plus miles each time, but factor in cold starts, short runs etc and you are going to want to change more frequently, personally I would say no more than 8000miles/12months, I’ve done this for many years even on very low use cars, ie 2-3000 a year, and I’ve never had any engine issues, no timing chain problems or worn bores, I’ve bought a couple with issues but still, apart from one, managed to get by with minor repairs and good maintenance. Sludge is a killer, I’ve had this on a Golf Gti as I started using the car as intended and changing the oil regularly it washed the sludge into the sump blocking the strainer, caught it in time, cleaned out and ran the car for 7yrs before passing to a friend who ran it for a few more, no issues! So I, as a technician, not on cars but related special vehicles ie they have engines and wheels, don’t buy into the idea that using an oil not specified is going to damage an engine in the short term, long term maybe, but only if you are taking it to max drain intervals and/or it is really poor quality.
One big issue we had with a particular engine was the low ash oil for dpf protection which appeared to wear items that we had never seen wear in before and bottom end failure at very low usage (equivalent to less than 100000miles) if the oil wasn’t changed regular and maybe 200000miles if it was, these engines would typically do in excess of 400000miles, or the equivalent, we even went back to using non low ash oil on contracts and fitted bigger filters as fitted to the euro 5 version of the same engine which never suffers a bottom end failure and I mean never unless no oil or oil pressure of course.

 

It is highly unlikely the CPS solenoid valve will cause this, possibly a faulty tappet, also the cps will shut off if it senses a solenoid has an electrical issue but other than causing a misfire if the valves are stuck in high lift there is no feedback from the tappets.

My car also has this trait, you can almost hear the knocking through the exhaust pipe, idle is always steady though but i have had a cam/crank correlation error just once when pulling away hard on a cold engine just as the traction control kicked in, chains appear tight (at least the bank 2) so i think it s probably a VVT unit where the locking pin has stuck or something, these engines are hard to listen too with the bonnet up, compare to the port injection V8 which is whisper quiet these sound more like a diesel, mine runs really sweet, smooth and great power, just don't run it with the bonnet up so i don't think its about to eat itself or throw bits out of the sides of the block. I decided not to investigate or spend money chasing the knock on warm start up, if it does cause issues i'm going to either sell for spares or have complete remanufactured engine fitted which will be better value than paying thousands stripping this one

 

Old car guy here. Admittedly not a foreign car expert. But since it's only doing this during warm starts and stops on oil pressure build up could be oil pump being weak and since it's warm only problem the oil is thinner so knocks because the pump is working harder to pump the oil plus less viscosity when then so tensioner bleed off would be more likely then. So on cold start oil is a bit thicker easier to pump and less bleed off. Just my 2 cents maybe a place to start looking is get oil pressure tested on cold start vs warm start. Good luck hope you get it figured out.

 

There is an anti-drain back valve that could be leaking?

When you remove the oil filter on top of the engine there should be a puddle of oil standing in the housing. If not that is a prime symptom of the drain back valve failure. It's not reported much but thought to mention it just in case.

The valve is mounted under the oil cooler brick. Inside the engine block.





Here is what it looks like after you remove the oil cooler brick.




Not well documented either.




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