Hello everyone, new here.
Thinking of purchasing a used 2010 XFR. Everything looks good, but the sound the engine makes at startup, cold or hot, is worrisome. Link below.

The knocking sound goes away after about one to two minutes of idling.


The car has a 80k miles on it. No timing chain replacement on record.

Sidenote: I also went to see a 2011 XJL, with 90k miles on it, and it made an even louder knocking sound on startup, which went away after about two minutes of idling. Either both cars are fine, or both cars have the same problem due to their mileage...

I've seen people say this might be:

1. Normal
2. Timing chain
3. HP fuel pump

Ideas?

Thanks in advance,
Peter from Montreal

 

Yes. Look at videos that have been posted showing various Jaguar engine noises. There are many and you will soon fine a match to the noise your car is making.
My guess is it's the SC snout making the noise.

I would also mention timing tensioners but you seem to know about them.
Now the SC snout is a somewhat easy fix and is a very common problem. I currently have a shut down clonk from this and have not changed the snout yet as it's not going to get worse and other than the noise it really is not much of a problem. Just something you don't want on a nice luxury car!

But the bigger problem is the water pump and rotten plastic cooling hoses/parts. Again plan to change these as a normal maintenance item. Do any of the cars come with service records?
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Hi, and thanks for the reply!
I looked at a lot of videos, but it's hard to find vids of 5.0 engines at startup and then idling right after from under the hood. Mostly, we see vids of startups at the tail end of the car, and for good reason ;-)

I found one vid that matches the rythmic, ''sowing machine'' type knock the engine makes, but unfortunately, the vid in question never said what it was. From what I hear of the little SC plastic gear in the SC snout going bad and doing weird sounds, the vids I saw of that problem dont match mine entirely. They made more of a gurgling, irregular plastic sound... Might still be that, but not sure... I'm hoping you guys can guide me before I purchase what might be a car that needs a new timing chain and guides. At the very least, I could use that as a negotiating tool...

BTW, how much does your local favorite Jag dealer charge, ballpark, to change the timing chains on one of these cats?

Thanks,
Peter

 

That sounds like a knock I haven't heard before - I'd say it's too low-pitched to be HP fuel pumps or timing-related, but I could be wrong.

The fact it goes away after a couple of minutes is interesting, suggests as whatever it is heats up it is filling clearance that shouldn't be there?

Rule out the supercharger by idling the engine without the belt connected.

 

It's all metal except for the coupler which IS plastic with a spring inside. Maybe they are talking about the coupler?
Those are a wear item so plan to replace it at some time. You can use a solid coupler or go back with the factory style coupler.

The timing stuff is hit or miss so unless the car has them done you don't know. Now with a 2011 model and 90K miles is it possible they may have done that repair already?
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Hi and thanks for reply…
the guy with the 2011 with 90k miles confirmed to me it is the original timing chain…

I found a video of a guy who has in my opinion the same exact sound… does it on warm startups after 10-20 minute shutdown. Alas, this guy ALSO doesnt follow up with final diagnosis…

what do you guys thik? Same thing?

any help aporeciated guys… what IS that knocking, sowing nachine noise? Arghhhhh!!!

https://m.youtube.com/watch?v=HzdmM1Arwl4

peter

 

Also:
just read in the jag tech manual that the timing chain tensioner is hydraulic, and that oil pressure takes some time to build up after a start, with a spring backup… this MIGHT explain why the timing chain noise, if it is that, goes away after 1-2 minutes following a startup, wouldn’t it? Tensioner pressure too weak at first, then builds up, then no more sowing machine noise…?
BUT: do ALL 5.0 AJ133s do this? If so, cool. If not, that still means the car I intend to buy is in need of timing chain replacement, doesn’t it?

 

If you're buying a 2010 or 2011 it will need timing chains done eventually. The issue seemed to be that the hard chain wears the metal guide and causes the tension to be reduced. In about 2013 ish they changed to a different timing chain width which is apparently a bit more resilient

Whether you get 90k miles or 150k miles will depend on life, oil changes, and prob some luck. But I would bank on needing it done.

Most I've heard around 90k make the noise. When it may become an issue is unpredictable.

Hard to tell for sure on a video but my guess would be that's the chain starting to rattle

If the price is right and the car is well maintained then you should budget for it in your plans.

Other issues like cooling pipes will prob be an issue sooner anyway...

 

It doesn't sound like a worn coupler/torsion isolator at all to me.
A worn coupler (and it was worn on my V6) makes a very erratic non-rhythmical high pitched metallic rattle, like marbles in a tin can, while the noise I hear in the vid is very rhythmical and regular and also deeper. It sounds a bit like a classic bottom end rod knock but if it goes away after a couple of minutes it can't be that.
Also the tell-tale symptom of a worn coupler is a loud "clonk" on engine shut-down as the coupler spring rebounds in the hole/groove it has worn.
My prime suspects would be:
a) a worn SC belt tensioner
b) a worn coolant pump/bearing
c) a worn high pressure fuel pump/bearing, especially number 2 pump.
An older AJ133 SC is prone to all of these things but they are hard to diagnose as they all sound similar and they all seem to come from roughly the same part of the engine.

 

Again, thanks for the input.
I am budgeting for dome repairs in the near future, but a TC replacement is a bit harsh for starters 😆😖
as for possible causes, thanks for the suggestions. I probably rule out SC tensioner since I saw a vid of a high mileage NA 5.0 making the same noise.dont know about the coolant pump… would it stop making that noise a few minutes after startup?
I’m still wondering about the timing chain tensioner hypothesis… being worn out, and needing more time to build up oil pressure to do its job correctly…
quite the little puzzle!

 

Sounds like the supercharger coupler wearing down. While the supercharger is out to do the replacement, you might as well change out the front lower and rear coolant y pipe & crossover.

 

I’ve seen a few people undo their supercharger belt and start it up to see if it’s the supercharger.

 

Well first follow Davetibbs advice as it's free and will rule out the SC completely. That's a start so report back after you have removed the SC belt and started the engine.
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Went to the Jag dealer.
Spoke to the service department's supervisor, who had owned for a few years a 2010 XFR (could have kissed him right there).
Made him listen to my video.
First instinct: SC coupler OR Timing chain tensioner worn out and belt slapping around till oil pressure at max level.
HOWEVER!
When I told him the sound disappears after a minute or two, that basically relegated the first option (SC coupler) to the garbage bin.
So timing chain, according to him. Not 100% sure, but says he experienced the same exact problem. People dont do regular oil maintenance, tensioner gets worn, which produces belt slack, then progressively more audible, rhythmical belt slap at startup...
Cost to change timing belt at Jag dealership: a whopping (get this): 8000$ (Canadian), so around 6400$US...

That sounds HELLISH!! I saw entire timing kits for 600$US on the web... Thinking of having it done outside of Jag entirely, but that opens an entirely new can of worms, and brings up one major question to you guys:

Do you recommend a job like this being done at a local mechanic? Or is this really, really something that only Jag techs should handle?

Thanks again for the support...
Peter

 

Lately I've seen a fair number of 2010/2011 owners replace just the tensioners and guides. The chains in the older cars are hard to come by now.

Personally I would walk on this car and find another R.

 

If you DO get it repaired I would make sure the guy has done it more than once. You don't want your car to be a training lesson for the mechanic!
I don't know your skill level but we have several very in depth guides for doing the repair yourself?
It is a big job and I have never done one.

I think I would listen to VicVegas84 and keep looking. Consider a later car especially a 2013 or newer for the improved 8 speed automatic. The later cars also got a MUCH improved electrical system. My 2014 XJ has been very solid and believe it or not I am STILL running the factory battery after 9+ years!! Never had a low battery error except for one time when I ran the radio with the doors open. The earlier cars eat batteries and have lots of electrical issues that Jaguar managed to iron out after a few years.

Now again before you do anything. Get that SC belt off and start the car. You want to make 100% sure what the problem is before you tear into anything. It's very simple so please report back after you run that test.
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I know this thread is old but my car did the exact same thing. It was indeed the timing chains failing.

 

saw this in another forum just today…. Man was complaining about warm restart noise:

“Just an update on this as it may assist someone in the future.

You can disregard any live data at just idle as the pumps have a valve which varies the output dependent on load requirements.

I had the live data tested against an other XFR and it was roughly the same. I replaced the fuel pumps as I suspected the warm restart noise some AJ engines get was either the pumps and or the cam buckets.

The warm restart noise has now completely gone and the live data showed a slight increase in pressure.

Not cheap but that noise was doing my head in.”