I have this engine noise sounds like cutcutcutcutcutcutcutcut the sound is constant and can only be heard when the car is idling I can hear it inside the cabin as well and gets very annoying in stop and go traffic

 

I don't know what is causing it, but I think it would help if you took the video again without the engine cover since it deadens the engine noises, and also have someone do a few light revs of the engine during the video.

 

It would also be a good idea to remove the oil filter and check for any metal particles. The Jag makes it very easy to do that compared to cars with the can filters on the bottom of the engine.

If this was a Lotus Esprit, my first thought would be a failed vacuum pump. Do these cars make that kind of noise when the vacuum pump is failing?

 

That sounds terrible!
At least you can rule out the infamous worn SC coupler/torsion isolator which sounds nothing like that.
The SC worn coupler sound is very irregular and sporadic, like marbles in a tin can, while your noise is very regular and rhythmical. Although it is possible that your noise is drowning out any SC coupler noise.
My best guess is a worn high pressure fuel pump, followed by a pulley bearing, followed by the coolant pump, followed by the SC belt tensioner.
Worst case scenario it is rod knock.

 

The noise is not there at first start in the morning (watch video) even when the revs are high
I let it idle for 15 mins and revved it a few times still I did not hear the noise
The noise gradually starts after driving for a few minutes and is loudest when I get off the highway

 

I will try running the engine without a belt attached to isolate the noise. if the noise is still there it's rod knock if its gone something else

You Tube

 

I checked the oil filter for metal particles when I did an oil change about 2 months ago and I just checked again after a long drive I have not seen any metal particles filter looks clean
Is it possible it can still be rod knock?

 

That's exceptionally good news to indicate that you don't have something super major wrong with the mechanicals of your engine.

 

Based on the video, the sound seems to be more pronounced on the left side (as viewed). I am curious if the noise is louder from underneath the car. If so, that would point to the high pressure fuel pumps. Otherwise, it could be something wtih the valve train. This is where a stethoscope (plugs in the ears with a metal rod on the far end) would be helpful as you can put the metal rod against the metallic parts of the engine and see where the noise is the loudest without getting your fingers in dangerous spots. You can then atleast say "the noise is coming from XXXXXXX area" vice just saying "I have this noise".

 

I bought a stethoscope off Amazon and the sound is coming from left side of engine just like in the video and most loudest when I had the probe on the left side valve cover
What I don't understand is why the noise is not there on start up first thing in the morning even after idling for 10-15 mins the noise starts after driving and on start up whenever the engine is still warm and only in idle as soon as I drive or rev the noise disappears

 

You recently had the vacuum pump off to repair the oil leak. Any chance it is coming from the vacuum pump?

 

I will check vacuum pump and other areas underneath the engine with the stethoscope

 

JaguarXJL15, As for the noise only being present at certain times, something that can happen is as the car changes temps, there are different metals in the engine (aluminum block, steel pistons, brass sensors, etc). All these metals expand at different rates. It is possible that with machining tolerances, you can reach a point that when the motor is cold, something may be just fine, but you get it warm and it can possibly be too loose or too tight (depending on how the metals are). Either way, that can start creating noises.

Keep probing and see if you can narrow it down to a more specific spot.

 

What damage would low engine oil do to the valve train? I probed everywhere even under the engine the left valve cover is where the sound is coming
It is most likely damage caused by low oil due to the vacuum pump leak

 

JaguarXJL15, low oil could possibly have damaged the VVT system in the car which may explain why it only does it once hot as I am pretty sure that the VVT system is not used when warming up the car. So, it would be locked into a given position. But, once the motor is warmed up, then the VVT will start working and that may introduce some slop, leading to the noise. After that, not sure as any wear created from lack of lubrication would be present at all times and conditions. I guess you could possibly have a stuck lifter, but again, that would be an unlikely situation.

 

Wow, do we have the same car?

I had my shop replace brake vacuum pump seal, was leaking some oil a couple weeks ago. Runs fine, no metal in oil, but I noticed the attached noise a week or so after picking the car back up. I dropped it off again, and they found this ticking noise to be coming from the drive belt system. I used my stethoscope before dropping it off, and felt that it was in that area as well, so I'm glad the 2nd opinion matches up.
Based on your video, I don't think we have the exact same noise, but it seems similar.

Remove the belt and see what happens. I approved them to just refresh all 5 idlers and 2 drive belt tensioners as well as replace the FEAD belt since it's time. It was looking kind of worn. Got the car back yesterday and the ticking is gone.

How low on oil were you? When I noticed the leak, I stopped driving it. I took probably 2 or 3 hard pulls in that time I was 1-2 quarts low. I did an oil change on Friday and I sent my oil in for analysis, just in case. Didn't smell like gas nor show any metals, so I am curious what it will return on 2900 miles of use.

 

I tired removing the belt but I was not sure how to do you turn the bolt on the tensioner clockwise until it moves?
I was 1 liter low on oil since repairing the vacuum pump and topping up the oil the noise has reduced by about 50%

 

Youll use a long bar to turn it. It's interesting your engine noise changed with more topped up oil. Mine did not change at all with an oil change or increased oil. You may have multiple things going on, it would be prudent to run this by a shop experienced with these vehicles (either land rover or jaguar 5.0s.).

 

Worth mentioning the vacuum pump looked like it was leaking for a long time I recently bought the car I have no Idea how long the previous owner was driving around with low oil levels

 

If it is the VVT will it get worse or stay the same? What if I use thicker oil? 5 30 instead of 0 20 or this fuel cleaner in the reviews some people said it stopped their engine knocking noise

Concentrated, detergent-based fuel additive cleans injectors, carburetors, valves and combustion chamber deposits with a concentrated blend of the most powerful high-temp and low-temp detergents available.

Q:will this fix engine knock?
A:Yes, this could fix engine knock, it is a very good product and lives up to what it is suppose to do