Hi there!
I'm likely going to be buying a 2006 XK8 that seems to be in pretty fantastic shape... except there's a ticking sound at idle after a cold start, and I'm assuming, continues after warm-up.
I'd love some input here as I'm pretty sure it's not a timing chain tensioner issue. I was told it's the fuel injectors. Curious to know if that means a replacement would be eminent or if the sound is "normal".
Having previously owned a 2009 Cayman S, I'm familiar with noises that sound more ominous than they really are!
Thanks in advance for any guidance!

Link to cold start up video:
https://drive.google.com/file/d/1Ibt...p0nnwCHnz/view

 

Hi,
IMO it's not injectors, and definitely not normal. Injectors 'tick' pretty quietly - that sound is too loud, and I'd not expect to hear it from behind the car.

Possibly something in the accessory train (serpentine belt):- others more experienced will chime in, but I'd want it investigated before jumping in.

 

I agree with Michael - to my ear, the sound is too "heavy" to be a fuel injector, but not heavy enough to suggest a piston rod bearing.

My first question is, what is the current engine oil level and what viscosity was used at the last oil change? What service history comes with the car? Has the oil been changed every 5,000 miles?

It could sound like a sticking tappet/lifter. It seems to have that sort of "weight." It could be a problem with a variable valve timing actuator also.

It would be worth changing the oil and filter with Castrol Edge Euro Car Full Synthetic 5W-30, a Mann W713/29 filter, and a bottle of LiquiMoly Hydraulic Lifter Additive or Rislone Maximum Performance Engine Treatment to see if the noise is reduced or eliminated. But I would not purchase the car in its current condition. No telling what problems you may be inheriting.

Cheers,

Don

 

There’s a piston slap noise when the engine is cold that could be considered normal for these cars.

it should go away when the full temperature is reached.

Z

 

How many miles on the car?

-Dave

 

The more famous ticking sound at idle is typically from the purge valve in the wheel well, driver side. It is normally heard on and off at idle, sitting at a light. From memory, it has a cycle (ticking for one (?) minute, then quiet for a while). Jaguar has provided several fixes over the years (hence the many part# for the purge valve), including wrapping the valve with a sound deadening cover/wrapping blanket. Should be easy to rule this possibility in or out now that you know of this source.

Another design flaw with these later models is the pulsation dampeners on the fuel rail. They can develop leaks that are less that straightforward to fix. One such fix is to take them out and weld the openings shut. If the dampeners are gone, some "injector" noise could creep up.

Best of luck, keep us posted.

 

The frequency of the "tick" seems to suggest valve related issue, like the stuck lifter mentioned by Don. Having listened to many a sticking lifter in 60's & 70's GM cars when I was a dealer mech back then, that's where I would be looking. Sometimes you can open the oil filler cap and get an extra dose of the sound.

 

I believe just under 65,000.

 

Thanks!
I think I've decided to pass on this one for now, despite it being absolutely beautiful and otherwise in great shape. I'm in Chicago and the vehicle is in Virginia (DC area) so not being able to poke around myself has got me feeling it's for the best.
I had originally been gunning for an F-Type R, but this XK8 looked/looks to be in such great shape that I gave it genuine consideration, especially with the considerably lower price.
Thank you all for the input!

 

I'm late to the party, but my engine does the same. The car didn't run when I bought it. I have carefully tracked mine down to cylinder 8. My best guess is that Mr. Bumwrench, they guy who replaced the heads, didn't quite get the correct valve clearance on cylinder 8. It's annoying but doesn't seem to hamper the performance. One day I'll get around to verifying it.