X-Type v6 air intake sound on idle

[foolin]

Hello, i recently bought Jaguar X-Type 2002, 2.0 petrol. Some strange
sound is coming from air intake, i dont know how to describe it
exactly, it's like some guggle noise. It comes for a few seconds when i
let go gas pedal and engine goes idle. The sound is there for a few
moments and then goes away.. English is not my native language so sorry
for mistakes:) Any help would be appriciated, thanks

[Steve0002]

I have the very same issue, no lack of performance just this strange gargling noise coming from the air intake.

[Old Peter]

Welcome to the Club, Steve and Foolin.

 

It is possible that the noise is from the Climate control resetting itself.

 

I get it also and was told that it is normal.

 

I cured it by turning up the radio.

 

Regards,

 

Peter.

[Steve0002]

Hello Peter,

Thank you for the welcome. I don't think the noise is coming from the climate control as you can hear it from the air intake.

I did some research this afternoon to see if anyone else has this noise, I did find this on YouTube

it has the exact same noise. The engine itself runs like a dream it's just one strange noise that is bugging me.

Any ideas would be great.

Many thanks

Steve

[Jaguar Owners Club]

HI Foolin and Steve...welcome to the club!

 

well that is a very strange noise...the only thing I can suggest is that there is a split in some trunking somewhere and it is acting like a trumpet(?) by amplifying the resonance of the intake air.

Hope some members can shed some light on it as it is rather strange !

 

Regards    Trevor

[Steve0002]

Hi Trevor,

 

Thank you for the welcome, I have to say, this noise has me fooled that's for sure, I can't seem to find anything online except that video. I'm sure it will be something obvious, but I can't find it 

 

Steve

[braincrush]

i can hear exactly the same noise, noise i've heard before, i used to play with RC planes with little nitro motors, and when you simply spin the propeller by hand, that was the noise the cylinder was making sucking the air.

Is your motor misfiring by any chance ? 

[Steve0002]

Hello Sebastian,

The engine isn't misfiring in fact the engine runs really well, it's just that noise.

[braincrush]

Righ, well my theory was it's made by the piston pulled down by crankshaft without the ignition, but I am probably wrong if your engine is working properly...

[brad]

I get this noise as well on my x type 2.1l v6 02 plate

[msmicksmith]

That, to me, sounds like fuel igniting in the inlet. In the old days of carburettors, you could get this. It was know as 'spit-back' then, and fuel would be 'spat' back into the carburettor and ignited. Removing the top mounted air filters could sometimes result in flames being spat into your face as it ignited. In those days it was caused by incorrect timing. Given that your Jag will be electronically controlled, timing is not adjustable.

However, you say the car runs fine, which I'm sure it does, above idle speed. At idle, the flywheel smooths out any imperfections due to its mass which turns the crank via momentum. Any minor misfires will be largely unfelt due to the flywheel mass, but will still result in a lack of pressure on any given piston. If there is any incorrect burning of fuel in the chamber, it will be forced into the next available opening, usually the exhaust and burn up there. 

There are various things which can cause fuel ignition in the inlet, the main one being a worn inlet valve, but that would result in a rhythmic sound as the same piston would have the fault every time. Generally, sounds like this are caused by poor ignition - ie spark plugs & leads. What happens is that the voltage  applied to the ignition High-Tension (HT) side increases with rpm (to a point), so at idle the spark is weaker than at higher revs, purely because it doesn't need to be. At this lower voltage (bear in mind that it is still around 12000 volts!), it travels all the way from the coil, through the HT lead and down the spark plug where it jumps across the gap to earth, causing the spark which ignites the fuel/air mixture. As the revs increase, so does the voltage produced in the coils, and any insulation weaknesses cause the current to leak to earth before reaching the spark plug gap, which results in either a misfire, or a poor ignition which means the fuel in the chamber doesn't ignite fully and you get unburnt fuel left over. 

At low engine speeds, ie- idle speed, the flywheel momentum is enough to disguise these minor misfires and you generally won't feel them, but the lack of a full spark causes the misfire nonetheless. At higher speeds (and it only needs 100-200rpm extra) the flywheel has more momentum and masks them perfectly, and the coils are producing more voltage which reults in a bigger spark and the missfire is largely unnoticed unless its quite large. The engine in the video link you posted is seriously misfiring whilst the guy is trying to rev it up. 

The issue here is that these misfires cause damage. If it's popping like that in the inlet (and I'm diagnosing over the internet here), then it's as a result of fuel being ignited in places where it shouldn't be. It's possible, with EGR circuits these days, that it is igniting in the exhaust and being heard throughout the system, but if it is a misfire causing it, to that degree, I'd be concerned.

If it's left it will cause grooves to be etched into the valve seats and that requires the fault rectifying in the first place and then the valves regrinding or the seats and valves replacing. Cylinder head off and not cheap.

 

On a dark night away from street lights, crack open the bonnet and have someone rev the engine from idle quite briskly. If you have any problems with HT lead insulation, you'll see them light up like a chritmas tree as the current leaks to earth along them. Keep your fingers off them. I know from experience what 25000 volts feels like! If they are good, check each spark plug. If they are old, replace them. Signs of leakage are grey lines running along them. It looks like someone has drawn a line down them with an HB pencil. This is where the current is 'tracking' to earth instead of flowing through the centre.

 

If it's not caused by ignition, then there really are only a couple of alternatives. Faulty head gasket or worn valves. If the gasket has blown between two adjacent cylinders, the gasses will be ignited in one, then forced through the gap into the adjacent one. That adjacent one will have a valve open as it will be on a different part of the 4-stroke cycle, and the burning gasses will enter the inlet or exhaust as a result. Again, I'd expect a rhythmic mis-fire if that were the case, hence why I suspect ignition faults with your engine as the insulation on 6 HT leads will break down pretty much simultaneously and cause random misfiring instead

[msmicksmith]

In addition (sorry for the length), spark plugs usually have a life of around 20k and HT lead will usually be knackered by 40-60k. If you have a car at around this mileage, or double, then expect them to be b**gered. (Double would mean I assume they have been replaced previously)

 

I had a Vectra V6 a while ago that ran beautifully but the HT leads were leaking quite excessively. Once replaced, the performance difference what amazing, and I thought it ran fine beforehand!

[brad]

Cheers mick

[Gordon2501]

Hi guys...i`m new to the club..ive just watched and listened to the video, my car is doing exactly the same thing, did you ever find out what the problem was, i dont know what to try next to be honest..any help would be appreciated, thanks

[chrissy]

Hi there I have just cleaned my EGR valve and I tested it with a hand vac pump and it makes a similar sound when it shuts it has made me think can you have intermittent fault that is making it open and shut a lot ? Try to disable it and see if it helps I think it's worth a go.

[Andrewhar47]

I have exactly the same sound. Only seems to be present when idling and the twin air intakes shake. When the car is in drive it makes the car jolt. Has anyone got any idea yet?

[RoniN_]

Hi!

I am new to the forum, so welcome everyone.

The problem we have here is most likely gaskets (uper or lower) on the inlet manifold, Parished gaskets on the throttle body, or air leak somwhere. One of the chap from polish Jag forum had  that problem as well and manifold gaskets, cat converter B1 sort the problem out. 

I know its an old post, but hopefully will help someone

 

[AshB123]

I know this is an old thread, but i have just solved this problem on my X-Type, and i have noticed that just after the year that my car was made, Jaguar installed a different throttle body on newer cars and they don't have the part that's playing up on them.

The part that causing the problems for you is the IAC (Idle Air Control) Valve. Its the part that sits on top of the throttle body. Take the throttle body off, and clean it, and take to IAC Valve off the top and clean that, give it a good squirt of WD-40. I've just solved this problem on my own X-Type.

I know this is an old thread, but just thought I'd throw a solution out there

[Milo]

Hey guys I have the same issue on a 2l v6 it stared 4 months ago and one day it just disappeared and the car was fine till I had the engine wash. I drove off car was fine got home and after 2 hours drove to shop and the problem was back I check for leaks don't hear any but the car does this hissing sound by the air box when idle and slight shudder on driving the workshops are of little help only waiting to fault find by buying parts after parts on my expense and not getting to issue any ideas of people who had the same issue. 

[Vivavoce]

(preface: Im in Australia so air temp is not cold in the morning lol)

 Just purchased a 2005 V6 2.1 about 2months ago, it makes that exact popping/spluttering noise when it idles on first start of the day. After the engine revs and then settles (out of park)  the noise will stop and the car drives like a dream. The noise will not occur during idle again during the day. Really hoping that by 2021 somebody can give me a "most probable solution" that they had fix their car! 😁

[Amal]

I too have the same issue in x-type- the dup dup sound on idle, along with misfire on sudden acceleration. anybody got a solution for this? (Already replaced spark plugs, but still the issue persists)

[Xtype2002]

Hi all, I'm new to this forum, would appreciate if anyone has solved this issue - I can understand there may have been several different faults (if they were air leaks in the air intake system eg vauum leak(, however aftr checking everything except for the EGR valave operation - Ive run out of plausible options. Ive replaced the plugs and coild packs with NGK brand. Checked with soapy water all of the air hoses/cpnnections that i can view from the top etc. I also removed the IAC valve, it opens around 3-5mm when activated and seems free, is this enough? Is it possible it is not holding it open enough or is fluctuating?

I have some fault codes -

P0037 & 57 both HO2S  heater control circuit low bank 1 & 2 sensor 2 (both codes)

P1646 Auxillary inouts auxillary outputs

P1647 Heated oxygen sensor control module bank 2 open/short

Is it possible any of these are the cause, it seems odd, it only occurs during cold start and intermittent during that period, so hard to diagnose when warmed up...

My car has no misfires, I did notice a small amount of Oil in the manifold balnce bowl when replacing the o ring...

Thanks,

Shane