I have a 2012 Jaguar XK with the 5.0 and about 35,000 miles. In the last couple of weeks, I have heard a rattling sound coming from the top of the engine. This is different than the posts i’ve found on this forum since mine happens all the time; engine cold or fully warmed. At first, I thought it might be my water pump going bad, because I also had to top off my coolant reservoir a couple of weeks back. The tank never went empty, just down about a quart. More on my rattle, I can’t hear it when the car is driving at speed, only hear it at idle when standing outside the car. Since this happens well beyond cold start, I’m hoping for some ideas on what might be going on. All my past issues with this car have been battery related - I’m pretty sure this issue won’t pass with another new battery, LOL!!

Also, I posted on the geographic forum looking for a mechanic referral, but haven’t received any input. The car and I haven’t been in this area (Columbus Ohio) long enough to know who is skilled and trustworthy in the diagnosis/repair of Jags. I would appreciate any recommendations and/or experiences with shops in the area. I am willing to travel, or trailer the car to any regional expert with solid experience and ethics.. I am aware that there is a good dealership presence in the area, but I get the impression that they shy away from older vehicles and my first hand experiences with them have not inspired confidence.

Thanks in advance!

 

Re: service near Cols. You might try NJB Automotive in Westerville, OH. They are known for Ferrari and other Italian, and that's where I take my Ferrari. But they service other foreign makes as well. Very competent and reasonably priced.

 

Thank you, David993S! I was unaware of and will definitely look into this shop!

 

My search of the interwebs has also come up with Auto Assets and Toy Barn as possible service providers. Does anyone have any first hand experience with these places?

 

Just tested it again this morning. Today, nothing unusual was discernable at cold start (in a 55degree garage - LOL). Increasing idle speed didn't change anything. However, after about a 30-minute ride, the engine was making the rattle sound at idle. I turned off the AC, no difference. If you listen closely, it is random and sounds like there is something taping on the plastic. It doesn't seem to be rhythmic or in a specific time which I'm taking some encouragement from (???). Any ideas what's going on?

 

I haven't used either, but I have heard some unfavorable reviews of Toy Barn. But again, no first-hand experience with them.
Before you take it anywhere, raise the hood and poke around. You might find something simple that is loose.
Cheers.

 

Invest in a mechanics stethoscope. Cheap and lets you pinpoint noise origin. Stay away from the fan and serpentine, of course.

And if you're losing coolant, keep an eye on it and get it to a shop. The tanks can crack, the hoses under the manifold are known to leak, and the water pumps a known to leak. Could, of course, be none, one or all three. Losing coolant is A Very Bad Thing on these.

 

An obvious possibility with the 5.0 engine is the poorly designed cam chain tensioner although at only 35k miles that would be unlucky. This can be checked quite easily by checking the tension on the cam chain where it runs under the cam cover.

Richard

 

Im with Ruchard on this one , although not a 5.0 i had time chain issue on the bulletproof 4.2l

 

The 4.2l and probably the 5.0l have a plastic cover on top of the engine, that is held on by a few fasteners. Remove it to reveal a lot of connections.
Then try it like that for noise.. Put a listening devise to the parts there....

 

I saw a chap on YouTube who indicated that JLR made a design improvement to the 5.0 chain tensioner system in 2012. Does anyone know when in 2012 this change was made, or how to find out which VIN’s benefitted from the improvement?

 

Thanks to all who have been providing ideas and guidance. While I don’t yet have a mechanic stethoscope (on my list), an old salt mechanic once showed me how to use a screwdriver to the ear to pinpoint noises and vibrations. I’ve been trying, but the plastics aren’t lending well to me pinpointing anything. Also the fact that it is very random isn’t helping either. The other thing I’ve done is remove the oil filler cap, and gently press on the reachable chain with a long screwdriver. There was barely any deflection and certainly nothing that seemed loose enough to reach the plastic valve cover. At least this is the case for the driver’s side chain - short of tare down, I have no way to confirm similar chain tightness on the drinker’s side cylinder.

I’m still searching and appreciative of your best thinking. The weather has turned snowy/icey around here so it will probably be a couple weeks before the Kitty gets to the shop (where-ever that ends up being)

 

I thought it might just be the ubiquitous fuel injector tick tick tick coz GDI but after listening to the vid it ain't that it's definitely a rattle not a tick.
My money is on timing chain(s) and/or tensioner(s) but another possible culprit is one or both of the high pressure fuel pumps which are notorious for becoming rattly.
They are mounted low down on the right side engine block (passenger side on a US car), and even though they are mounted low the rattle could sound like it is coming from much higher up.

 

That’s an area I haven’t explored yet - thanks! When our roads clean-up (hopefully next week), I’ll,take the cat out for a run then explore the underside for possible noises originating from down under! Cheers!

 

That sounds more like a rattle from a bearing on an alternator or idler.

 

If the chain has virtually no deflection between the sprockets then, as you say, that is a very good sign. You would need to remove the cam cover to check the righthand side which is not a big job but probably only worth doing if your screwdriver stethoscope suggests that the noise is coming from that side only.

An ODB scan might also provide some clues as it sometimes picks up slight changes in cam timing at a very early stage.

You could try and rule out any noise from anything which is driven by the accessory/serpentine belt. On other cars, I've released the tension on the accessory belt tensioner whilst the engine is running but I don't have a 5.0 so I don't know whether that is possible on that engine. It would be very difficult on the my 4.2 so I would slip off the belt whilst the engine is not running and then start it for a few seconds without the belt. If the sound changes then you know it is something which is driven by the belt.

Richard

 

Thanks everyone for their best thinking. I just got the car back from the shop. The leaking coolant was from the water pump. It has been replaced, and the random rattle sound is gone too!

 

Be sure to change the oil every 5k and or annually at minimum to keep your timing chains in good condition