Knocking noise from engine until warmed up (w/ audio)

Engine, Exhaust, Drivetrain, ECU Faults and Fixes
sg1
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Knocking noise from engine until warmed up (w/ audio)

Post by sg1 » Tue Oct 10, 2017 7:57 pm

Hi everyone,

I've recently bought a second-hand XE 20d (180 PS), and I can say I really enjoy this car. However, I've noticed a strange knocking noise from the engine, which gradually disappears over the first 5-7km after cold or not-so-warm start. From inside the car, it sounds like someone would hit the engine block with a wrench lightly. The knocking changes with the engine speed.

I've attached a short audio sample, where the engine goes from 1400 rpm to 2000 rpm, then shifts up and again begins from 1500 rpm. The sample is heavily amplified and eq'd, so the actual sound is slightly different and not as loud. For example you wouldn't notice the noise when music is playing.

The noise appears under the following conditions:
  • engine isn't fully warmed up
  • throttle is applied (immediately disappears otherwise)
  • car is accelerating in low gears (e.g. when driving in a city)
Local Jaguar dealership claims it's normal. However, it doesn't sound like normal diesel engine noise to me. Furthermore the knocking comes with exactly half the engine RPM, and thus a single cylinder would be likely to cause the sound (e.g. everytime it fires).

I really would like to know if others experience the same with this engine, and how this compares to the sewing machine rattle issue. The car is definitely beyond its run-in phase.

xe_knocking.zip
(actually MP3, had to zip it due to board restrictions)
(81.37 KiB) Downloaded 34 times

XE 20d 180 MY17


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CaptainNoddy
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Location: Ireland

Re: Knocking noise from engine until warmed up (w/ audio)

Post by CaptainNoddy » Tue Oct 10, 2017 8:38 pm

I hear nothing unusual in that audio sg1.

All diesels are a bit clattery when cold and get quieter when warmed up. Mine is noticeably better after it’s warmed up.

The sewing machine rattle is possibly hiding in there and I would say the engine earth cable change under warranty would do no harm. It is an extremely quick job and may improve things, but I wouldn’t worry too much from what I can hear....
MY16 XE 2.0 D AUTO 163PS, Ammonite Grey, Cold Climate Pack, Parking Pack, 10 way Seats, Xenon headlights


malawbrook
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Re: Knocking noise from engine until warmed up (w/ audio)

Post by malawbrook » Thu Oct 12, 2017 6:51 pm

I can't hear anything unusual on the audio, but what you describe is exactly the same as I am experiencing. It is not a cold diesel sound, and I don't think it is coming from the engine, because you only hear it when the car is under load, and if you rev the engine in neutral you cannot hear it. Also, it takes a good 30 minutes to fade away, which suggests that it is not coming from the engine itself, which would warm up much quicker. I have tried to get Jaguar to tell me what it is, but they either ignore it or tell me that it is "normal". I'm not giving up!


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CaptainNoddy
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Re: Knocking noise from engine until warmed up (w/ audio)

Post by CaptainNoddy » Thu Oct 12, 2017 7:20 pm

This is my fourth diesel and almost all their noise while driving is only under load. All except the engine in the Qashqai - a mongrel of an engine that sounds like it has tin cans for cylinders - is quiet enough when off the power to not be able to hear it at all.

Revving the engine when in neutral will not reproduce the same conditions as under load so I'm afraid that doesn't isolate the problem for you malawbrook. There will be no noise when not under load but plenty when driving under load - that's perfectly normal.

My first X-Type with the Ford Duratorq engine had quite a harsh rattle - more like an industrial sewing machine - when under load and particular RPMs. The Second one, which was slightly tweaked for more modern emissions standards was better.

The Ingenium is the quietest I have had. I still think I will get the earth cable changed anyway as I do have a small amount of under load rattle. But overall I am very happy with it.

Remember that the Fuel Rail runs at about 2,000 bar on these things. That's about 25,000-30,000 psi! It's an insane amount of pressure. Even a tiny injector open and closing at those pressures will make noise and a high pressure fuel pump will knock like a frying pan as a result. That seems to be where the XE's rattle comes from. The noise travels down the earth cable and into the passenger side chassis. And it's why under load is so different from neutral.

All four engines I've had need(ed) at least 10-15 minutes on the motorway before they('d) become warm enough to be noticeably quieter. It is not just mid range coolant temperature that you need it seems. All the components of the intake and peripheral systems seem to need to get up to temperature too, and that seems to only happen through conduction from the engine block, so it takes it time. Lower speed driving may well take longer.

If this is your first diesel car, then it may be just that you are not yet aligned with what to expect. They are noisy when ticking over at a standstill. Noisy while driving away until you get to about 30mph and the road noise can muffle it a bit better. And noisy when under load. They are MUCH MUCH better than the diesels of old, but noisy nonetheless.
MY16 XE 2.0 D AUTO 163PS, Ammonite Grey, Cold Climate Pack, Parking Pack, 10 way Seats, Xenon headlights


sg1
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Location: Germany

Re: Knocking noise from engine until warmed up (w/ audio)

Post by sg1 » Thu Oct 12, 2017 10:14 pm

Thanks for the detailed explanation! Indeed this is my first diesel. I'm aware that the sound of such engines is generally more rough, and now and then I've driven a car with one. However what I hear now has just something unusual to it.

I'm experiencing the same that both of you describe: The coolant is already warmed up, but the engine still takes its time to become quiet. So that's normal to some degree I guess.

I did a second recording today using a studio mic. Now you can hear the sound much clearer, in the first audio it was nearly drowned by the general engine noise.

Also I made another appointment with the dealership. They want to show me the exact noise on one of their cars. I'm really curious!

xe_knocking2.zip
(MP3 inside)
(190.67 KiB) Downloaded 22 times

XE 20d 180 MY17


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Vespa
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Re: Knocking noise from engine until warmed up (w/ audio)

Post by Vespa » Sun Oct 15, 2017 1:11 pm

There have been several retailer fixes for engine noises and the current one is H027 relating to a camshaft fault. It is an electronic fix. It may NOT be involved in any noise you describe. There were past problems with the exhaust and mountings. It maybe worth getting them all check out to see what is outstanding on Topix for you car.
R Sport 180 in Bluefire with loads of extras. ;)


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CaptainNoddy
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Re: Knocking noise from engine until warmed up (w/ audio)

Post by CaptainNoddy » Sun Oct 15, 2017 4:20 pm

sg1,

In your last audio clip there is a tiny little isolated and singular tap noise. It happens twice about halfway through and again just before the end. I assumed this was just some background from holding the mic or phone or whatever. Is this the noise you are talking about? Or is the engine noise and that is continuous under load?

If it's the engine noise, there is absloutely nothing strange about your sounds and it sound exactly the same as my 163ps diesel XE. In fact, with my eyes closed I wouldn't be able to tell the difference between your car and mine.

Here is a short clip from my dash cam audio. I had just turned into a junction and started to climb a hill so the engine RPM stays high for a bit before dropping off before the next turn.

The audio quality is crap. And Jason Mraz really doesn't sound all that great anymore. Plus my new wipers are squeaking when they stop!
Barrys XE Sound.zip
(165.9 KiB) Downloaded 8 times
Let me know how this sounds to your ear.....My XE's engine sounds great to my ear (as far as Diesels can!) and is the most refined diesel (if there is such a thing!) as I have driven....
MY16 XE 2.0 D AUTO 163PS, Ammonite Grey, Cold Climate Pack, Parking Pack, 10 way Seats, Xenon headlights


sg1
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Joined: Tue Oct 10, 2017 6:30 pm
Location: Germany

Re: Knocking noise from engine until warmed up (w/ audio)

Post by sg1 » Wed Oct 18, 2017 10:57 pm

@Vespa
In topix there are only items prefixed with an "I" (e.g. I189), everything else must have been fixed already before I got the car. By the way, does anybody know what these items stand for? They have neither a title nor documents associated.

@CaptainNoddy
I'm talking about the continuous noise. The sound you are referring to must be me securing the mic in the cup holder. Thanks for providing your audio, this helps me a lot! Indeed our engines sound quite similar, they have the same low-frequency rattle (which I nevertheless find kind of strange).

Now let's still see what the dealer's car does. I'll report as soon as possible.
XE 20d 180 MY17


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CaptainNoddy
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Re: Knocking noise from engine until warmed up (w/ audio)

Post by CaptainNoddy » Thu Oct 19, 2017 9:32 am

Let us know how you get on sg1!

For what it’s worth, after 10 years of driving various diesel cars, my XE is the quietest and most pleasant so far.

That low frequency noise is perfectly normal and healthy!!

Your dealer may find something that will help however as the fidelity of the audio may mean something is hiding that I can’t hear.

Good luck!
MY16 XE 2.0 D AUTO 163PS, Ammonite Grey, Cold Climate Pack, Parking Pack, 10 way Seats, Xenon headlights


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PhilB
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Re: Knocking noise from engine until warmed up (w/ audio)

Post by PhilB » Thu Oct 19, 2017 9:39 am

Whilst you are at the dealers get them to check to see if your car has had the earth strap update.

Info and technical references here:
viewtopic.php?f=19&t=4638&p=54572&hilit=

Apparently the strap could transmit noise from the engine into the cabin so an updated one is available.
XE S, My18, Storm grey Pics Black venoms/black pack, 18 ways, BSM, 40/20/40, ICTPro 380, parking pack, spare wheel.
07/15 to 05/17: XE S British Racing Green Pics


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