Oh man I'm really hoping this isn't something expensive like valve lifters or tappets. I returned from a longish drive and left the car on while I was checking that my lights are all working. Before I set off on my drive I checked and made sure that my oil is topped off. I'll check tomorrow morning to confirm that is still the case.

When I passed to check the front end lights, I heard this noise coming from the engine.

Engine noise.mp3

Clicking will download the audio file.

Edit:
I went and started the car again to listen to the noise again. This is about 20 minutes after I took the audio in this post. The ticking is still there, somewhat less loud than previously, and it does increase its frequency with engine speed.

 

I will assume that if no one has replied thus far, that means that it is nothing to worry about.

I did check the oil and it is full. Also, on a cold start, the noise is not very noticeable. After driving around for a while, the noise didn’t worsen. It’s only noticeable with the bonnet open. I’m thinking it might just be normal timing chain whirring sounds.

 

I tried listening but it comes up as "unable to open" after I downloaded it

 

Oh... I'm not getting that issue. What software are you using to open the mp3? It opens fine for me on both VLC and iTunes on a Mac.

 

Are we listening to what sounds like occasional very light tapping/ticking? How many miles on your car? How many miles on the oil? Sometimes a simple oil change will correct it (my Hyundai Genesis starts to get noisy like this if I stretch an oil change out much over 5,000 miles). I acquired my '05 barn-find XK8 at 83,000 miles and noticed the same kind of noise, especially during the first few minutes of warmup each morning but also throughout the day. Oil level was about half a quart low so I added 16 oz of Marvel Mystery Oil to the crankcase, drove 300 miles, and drained/refilled the oil (Full synthetic, 0W-40 "European Car Formula"). About a tablespoon of gloopy sludge drained out so I added a quart of MMO back in with the oil change (you can go up to 20% of capacity), drove another 1,000 miles, then changed oil and filter again (no MMO added this time). The car now has 105,600 miles on it and no more ticking. I'm a big proponent of 0W-_ _ full synthetic oil for automobiles calling for 5W-_ _ based on my own experiences, but to each their own. While some people feel that MMO is snake oil, 57 years of experience driving and wrenching on vehicles and farm equipment have only reinforced my belief in the abilities claimed for the product.

 

Yes, we are listening for the very light tapping/ticking. The car has just 77,030 miles. I did my last oil change in July about 800 miles ago. I used Pennzoil Platinum High Mileage 5W-30 full synthetic. Prior to that, I was running Liqui-Moly Premium Synthoil 5W-40 full synthetic. The oil is still a very light yellow/amber in color. I'm using the Royal Purple oil filter.

I have never used any oil additives on this engine, but I was considering MOS2 or Ceratec.

 

I could not hear anything beyond the normal injector click.

 

I guess that’s another vote in favor of me being paranoid.

 

Yeah not sure. I'm using my phone so who knows lol. What I'm reading though sounds pretty normal though

 

You might check out this thread had the linked ones about TC-W3
https://www.jaguarforums.com/forum/x...e2/#post753484

I have tried this and qualitatively found that it quieted down the injectors and also helped with the slow start fuel drain back problem the 4.2L single ended fuel system is prone to. Have been using the 2oz per 10gal ratio.

 

At first I was skeptical, after reading the thread you linked, and the rabbit's hole of threads linked within that, as well as the search on bitog, I think I will try it out. So, you're using about 4 oz per tankful? I mean, our tanks hold about 20 gallons or 75.3L of petrol, right?