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Winger
Site Moderator

Member Since: 15 Feb 2005
Location: UK
Posts: 3428

2016 Discovery 4 3.0 TDV6 HSE Auto Aintree Green

Asking questions like that might scare the chap away..........I suggest a search of his posts will confirm your enquiry, based on their content.

28th Aug 2006 7:42 am

Gareth
Site Moderator

Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26718

My D3 makes a slight rasping sound on throttle off, as far as I know, it is the turbo wastegate opening and 'dumping' the pressure on the exhaust side of the turbo. I think all turbo charged engines do this, some are very noisy indeed! just listen to the noise when a wrc rally car lifts off the throttle!

Mine has done this from day1 and now has 52k miles and its no worse than when new. I am not aware of a rattle though.

28th Aug 2006 8:11 am

catoperator

Member Since: 29 Jan 2006
Location: hampshire
Posts: 149

2005 Discovery 3 TDV6 Base 7 Seat Manual Alveston Red

wastegate

a few causes of turbo noise

Obstructed air intake duct to turbo compressor.

Remove obstruction or replace damaged parts as required.

Obstructed air outlet duct from compressor to intake manifold.
Remove obstruction or replace damaged parts as required.

Obstructed intake manifold
Refer to engine manufacturers manual & remove obstruction.

Air leak in duct from air cleaner to compressor.
Correct leak by replacing seals or tightening fasteners as required.

Air leak in duct from compressor intake manifold.
Correct leak by replacing seals or tightening fasteners as required.

Air leak at intake manifold to engine joint.
Refer to manufacturers manual & replace gaskets or tighten fasteners as required.

Obstruction in exhaust manifold.
Refer to engine manufacturers manual & remove obstruction.

Gas leak in exhaust manifolds to engine joint.
Refer to manufacturers manual & replace gaskets or tighten fasteners as required.

Gas leak in turbine inlet to exhaust manifold joint.
Replace gasket or tighten fasteners as required.

Gas leak in ducting after the turbine outlet.
Refer to manufacturers manual & repair leak.

Dirt caked on compressor wheel and / or diffuser vanes.
Clean using a Non-Caustic cleaner & Soft Brush. Find & Correct source of unfiltered air and change engine oil & oil filter.

Damaged turbocharger.
Find the correct cause of failure, replace turbocharger as required

28th Aug 2006 9:09 am

PSC

Member Since: 01 May 2006
Location: Johannesburg
Posts: 255

2010 Discovery 4 5.0 V8 HSE Auto Fuji White

Re: turbo

catoperator wrote:
i never heard of a electric motor in a turbo i would like to see more info on this if anyone has any thanks

It is a BorgWarner (KKK) BV50 controlled by electrical actuators, there is a tiny picture of a unit in the 02/2004 BW newsletter . Porsche use the same size unit on the new 911 Turbo ....

-- Paul

28th Aug 2006 10:29 am

PSC

Member Since: 01 May 2006
Location: Johannesburg
Posts: 255

Gareth wrote:
I think all turbo charged engines do this, some are very noisy indeed! just listen to the noise when a wrc rally car lifts off the throttle!

There are two dump systems on petrol vehicles, the exhaust pressure which is used to control boost (wastegate) and the DV (dump valve) which can be either closed or open circuit (the noisy type) and is activated by the build up of pressure when the throttle flap is closed. The pressure if not released causes the turbo unit to become unstable.

Most diesel engines are not throttled (hence the good economy and low pumpimg losses on part throttle), so they dont need a dump valve.

-- Paul

28th Aug 2006 10:43 am

catoperator

Member Since: 29 Jan 2006
Location: hampshire
Posts: 149

turbo

some interesting diagrams and info
http://paultan.org/archives/2006/08/16/how...etry-work/

28th Aug 2006 4:34 pm

Gareth
Site Moderator

Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26718

OK I get it now. I don't have a wastegate or a dump valve, therefore I too have a mystery noise on throttle off.

It has not got any worse and I did not even think about it until reading this post.

28th Aug 2006 4:44 pm

jacob

Member Since: 12 Jan 2006
Location: athens
Posts: 145

2006 Discovery 3 TDV6 SE Auto Vienna Green

hello there.

i have this noise on throttle off as well, and is more hearable
while you drive in narrow places(like some protective concreate fenders
at the side of the roads.)

any ideas what this might be ??

29th Aug 2006 10:16 am

offroad junky

Member Since: 23 Dec 2011
Location: Port Elizabeth, Eastern Cape
Posts: 5

2006 Discovery 3 TDV6 S Auto Tonga Green

Our D3 started with this a while back and it is progressively getting worse. While driving on a straight road or slight downhill and you are just just maintaining speed, not coasting or exellerating, there is an irritating rattle almost like a bearing thats gone on a shaft.....

The slightest incline and the turbo goes into boost, it's quiet and if you take your foot off the exelerator it is qiuet. I had it by the stealers and the workshop supervisor drove with it and he tells me not to worry about it because his does the same and that it is only the VVT linkages rattleing like that and there is nothing they can do to fix it. Not even tightening it up because then the VVT linkages don't work like it should....

Any one out there with the same problem and if so, what did you do to fix the problem....?

P.S.....

Well, just some history on my D3....the previous 'ignorent owner' had 4 different tyres on the D3 and caused so much propshaft wind-up that the right front universal joint as well as the front diff broke and was replaced by LR agents here in PE. The rear diff has a slight humm in it as well. I was thinking that rattle sound might have been one of the output shaft bearings on the transfer case but the LR workshop supervisor said that if it was the bearing, it will make a LOT more noise and will I hear it....

20th Jan 2012 8:55 am

europeancemike

Member Since: 04 Jan 2010
Location: chester
Posts: 15

Hello did you resolve the problem? Here's my own thread http://www.disco3.co.uk/forum/topic53986.html I am still hearing the noise and it seems to be slowly getting worse but doesn't seem to affect performance.

28th Aug 2012 9:24 am

Frenchwalker

Member Since: 20 Aug 2016
Location: Perth
Posts: 8

2005 Discovery 3 TDV6 HSE Auto Maya Gold

Omg did you figure out what the noise was, I am in the same boat around 1500rpm regardless of gear drop a gear and it goes away but defiantly a harmonic vibration of sorts
Had my local land rover workshop look for it but no luck

Bump this thread

20th Aug 2016 3:15 pm

RomP

Member Since: 19 Aug 2016
Location: Centurion, Gauteng
Posts: 7

2007 Discovery 3 TDV6 S Auto Indus Silver

FrenchWalker...i to have this issue...here is my story, posted elsewhere on this form for advise.

It is very specific to throttle position, torque, boost etc. I get this screeching noise from about 1500rpm, but gets much louder on 2000rpm...by "playing" with the throttle, I can get this noise to start or stop. Another thing I have noticed is that on a very long steep uphill, this sound gets worse on full throttle with a slight vibration and no matter what the throttle position is then it screeches terribly until throttle is deduced.

PLEASE NOTE: This does not happen when one drives around the block, stop and go between speed humps type driving, only when probably cruising over 80km/h and on long enough straight roads to get to this speed and when throttled back to start maintaining a cruising spreed from around 80km/h +.

1. Turbo related ? when on very low rpm 1200 - 1500 I can also get this noise to come and go depending on how I play with the throttle, not always able to reproduce, but sometime, maybe co incidental...
On cruising at about 110km/h on about 2000rpm the screeching noise appears and stays there, depending on throttle position which I can get to stop when accelerating. Acceleration is at this point not instant and seem lagging, but as revs built up, the noise immediately disappears when the next gear is auto selected. About 2 seconds later the noise is back and only goes away by either deceleration or accelerating out of it until next gear is selected again and so it goes on. In 6th gear this noise will come back, but now one will have to start breaking the sound barrier to accelerate out of this one.

I am aware of a "perished" small boost pipe up against the turbo. This in itself also causes a loud " whoosh" noisy when on boost and throttle is quickly lifted. Almost sound like excessive air forced out somewhere after coming off boost. Local Indie replacing all 3 boost pipes on Monday so that small issue will be resolved and maybe with less noise the main problem may be easier to diagnose.

Maybe a faulty Turbo Actuator...Seems like throttle position and actuator vs boost are not quite "talking" to each other. Logic tells me that when in boost and if one decelerates, the actuator does not move back fast enough to reduce boost or it may be that its over-boosting..IE when throttle is closed it’s still trying to boost...hope this explains my understanding of this. The reason I tend do lean toward a faulty actuator is that the previous owner had a system faulty ( actuator related), but another Indie lubricated the actuator arm clevis...this was caused by not driving enough and some cases are so reported on other forums. Previous driver probably drove about 11,000km in the last 18 months.
I have driven the vehicle now for 3 weeks and no system faults.

2. Torque Converter ? I just had the gearbox to ZF South Africa last Friday with a new fill and filter on special ( not a double flush) and ZF also confirmed no issues with the TC, but I have read about stranger things happen or mis- diagnosed on this forum.

3.Gearbox ?
My limited knowledge of Auto boxes brings me to the following logical explanation.
Once cruising speed is reached, this is mostly when the screeching starts. There seems to be little to no load on the gearbox and it’s in the gear it is in at the time. The screeching noise now starts as one ( Either ) slowly accelerates or simply tries to maintain current throttle position. I think this is important as its very clear this noise starts when trying to maintain current throttle position, irrespective of the speed,mostly starts from over 80km/h.
When slowly accelerating or maintaining current throttle position, all the clutches and plates and whatever else may now be slipping as torque builds up to auto select the next gear. This is where the screeching sound possibly comes from.
I say this because as I’ve explained earlier the screeching sound stops instantly as the next gear is selected. The process starts again when speed is slowly increased or steady throttle and noise is back until next gear is selected.
I have noticed when vehicle is set on auto cruise, the noise is not that loud at all, its still there but hardly noticeable. I suppose ones foot and throttle position has a different effect on the computers all talking together than when on speedo cruise.

I have also tried this in command shift, but somehow cannot quite reproduce the same issues in command shift. This I will test further over the weekend and give feedback on command shift testing.

Landyworx offered to put in some dr Tranny, but the mechanic I was handed over to said the oil level in the gearbox was full and and no way of adding anything when the box is full. ( I suppose he has not heard about parking the car drivers side up

so no dr Tranny added. Maybe this should have been done as I’m slowly starting to lean more toward glazed plates / parts etc. in the gearbox?

Is there a way to diagnose this PROPERLY and technically ( not just driving up and down the road ) by connecting some sort of diagnostic tool and see if it is boost related perhaps. Surely one can monitor boost as and when this noise occurs to try and determine if it is Turbo related.
If not Turbo, can one not run diagnostics on the gearbox whilst its driving ?

Here is what i have checked and done so far.

With turbo heat shield removed, with ignition on/off I can see the turbo actuator arm moving freely....also no engine system fault.
Checked all heat shield, plates, cover everything under the vehicle is tight and secure, no rattles to be heard when bashing or knocking on anything. This was done on a lift and thoroughly checked.

All other D3's i have driven in DO NOT MAKE THIS NOISE, so it certainly is not a common problem.

The noise on the vehicle is loud and unacceptable and very concerning as its is a noise caused by something about to break so turning up the radio is certainly not a fix , so I'd like to get this sorted out...anyone else with a better diagnoses or referring me to someone that actually can make the time can do a meticulous fault diagnoses with me.

20th Aug 2016 6:56 pm

Frenchwalker

Member Since: 20 Aug 2016
Location: Perth
Posts: 8

Wow are really feel for you sounds like you have gone down the rabbit hole with this one, i am keen to explore the CV joint\Propshaft direction.
my Disco voise is more of a rasping\ grinding noise...sound like two surfaces coming to gather to make a slow oscillation noise at 1500-2000, i can reproduce in command reving up to 3000 in 2nd gear and then its a constant sound at 5th/6th in the low RPM range with a very very slight touch of power and inclusive of Power of to idle Every single time.

i dont know if i can call it a screeching. i do have it recorded, i am going to try and cancel out the background noise and post it to make sure were all on the same page as far as noise is concerned.

i also found the TB from either another post or site, which sounds very familiar

Discovery 3/LR3 - Auto Transmission Noise in Manual Gear 3
"Summary:
A customer may report a concern of an unusual noise from the transmission/drive line when driving with manual gear 3 selected under light throttle applications between 1500-2000rpm. The noise may be described as a 'scraping' or 'dry bearing noise' but is not apparent in 'D' (drive) or other gears.

TSB LA307-001V2

This bulletin has been re-issued to correct the VIN range.

Cause: Under certain specific conditions, the torque converter causes an undetectable vibration which causes the transfer box drive chain to shake, resulting in the noise.
Action: On a customer concern basis only regarding the above, refer to the Service Procedure detailed in this bulletin to update the transmission control module software"

21st Aug 2016 9:50 am

Frenchwalker

Member Since: 20 Aug 2016
Location: Perth
Posts: 8

Finally some direction

SO i stumbled across a mob called Rovertech, and posed this particular problem that i\we are experiencing

he took it for a test drive and identified the noise at 1500rpm at slight load in the cruise and on the occasion when you lift off the accelerator pedal

they have had two previous customers with the same problem and they have nutted it down to the turbo waste gate, its dumping boost as its not required and that is the wonderful sound rattle that we have all come to love

they said you can replace the turbo but its a chassis off event to do the job.....

14th Nov 2016 9:01 am

RomP

Member Since: 19 Aug 2016
Location: Centurion, Gauteng
Posts: 7

Thanks for your feedback Frenchwalker. I do not quite understand the wastegate explanation as the D3 turbo has the variable valve system. No Wastegate. I do however understand that excess boost needs to go somewhere if not used, but the issue that bothers me is the vibration felt on the car when this Screeching / Grinding noise starts....I agree with you explanation as I seem to have a very similar noise when foot is taken off the throttle as you explained. I wish i knew what actually happens to the excess boost when not needed....to my knowledge there is no dumpvalve or similar to dump excess air when not used, so where does it go in a VVT turbo. This should make for some interesting reading up.

14th Nov 2016 1:23 pm