Disco311
Member Since: 02 May 2016
Location: Shropshire
Posts: 2
  
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| 4.4 V8 rattle/clacking sound |
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Hello one and all,
I have just bought a 2006 Discovery 4.4 V8 (Jaguar engine) with a very heavy rattle/clacking/knocking sound.
The sound is continous and doesn't seem to clear with revs, the noise is coming from VVT area on the left hand bank (facing the engine from the front)
The car has 128k miles with good service history up until 100k, upon strip down for investigation the oil filter looks rusty (I am assuming it's well over due and been neglected since 100k or so, although I could be wrong). This is defiantly not good and needs changing asap, would this have a affect on the heavy sound from the one side of the upper engine bank?
The secondary chain appear to be VERY slack (probably fine once running and oil pressure up?) Not sure if this is normal.
Could it be VVT noise? Due to poor oil grade maybe, but then I am thinking wouldn't both VVT units produce this noise?
Any kind of input would be very grateful
Disco311
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 2nd May 2016 10:44 am |
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Rich84
Member Since: 26 Jun 2013
Location: South Australia
Posts: 238
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From what you describe the cam chain tensioner is probably broken on that bank. Even with no oil pressure they are still spring tensioned; the chain should never appear to be slack while the tensioner is not compressed (and it's only compressed for install and removal).
You will hear a tapping or rattling while the tensioner gets oil pressure after some starts, but not a heavy rattling or knocking. Sounds like the damage is already done. 2008 RRS TDV6 - Chawton White/Black/Lined Oak - 20's, h/k, sunroof - 350K KM.
2010 Audi A6 3.0T S-Line - Phamtom Black/exclusive 2-tone valcona 184K
2000 Audi A4 avant 1.8t Q Sport - Phantom Black/black 385K KM
1990 Nissan Pintara TRX - red - lots of mods - 439K KM
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| 3rd May 2016 12:02 am |
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EstorilM
Member Since: 15 Oct 2009
Location: Virginia
Posts: 28
  
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| Re: 4.4 V8 rattle/clacking sound |
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Disco311 wrote:Hello one and all,
I have just bought a 2006 Discovery 4.4 V8 (Jaguar engine) with a very heavy rattle/clacking/knocking sound.
The sound is continous and doesn't seem to clear with revs, the noise is coming from VVT area on the left hand bank (facing the engine from the front)
The car has 128k miles with good service history up until 100k, upon strip down for investigation the oil filter looks rusty (I am assuming it's well over due and been neglected since 100k or so, although I could be wrong). This is defiantly not good and needs changing asap, would this have a affect on the heavy sound from the one side of the upper engine bank?
The secondary chain appear to be VERY slack (probably fine once running and oil pressure up?) Not sure if this is normal.
Could it be VVT noise? Due to poor oil grade maybe, but then I am thinking wouldn't both VVT units produce this noise?
Any kind of input would be very grateful
Disco311
Only thing I could think of doing would be to run a FULL (ie. like all 18)module scan of historical and current error codes (obviously most of them do NOT trigger a check engine light) and post the data to this thread.
Also run live data and see what the commanded and actual cam angle and timing advance is for both cylinder banks. You should know right away if they're either out of spec bank 1 vs bank 2, or out of spec for commanded versus actual on either bank. There are some tolerances for both values but if you're getting as much noise as you say you are, it should be obvious.
If it's a PHYSICAL ie. mechanical failure you should also be able to run a compression test on that bank and immediately know what you're dealing with and how serious. |'99 Discovery II | 177k mi. | Kinversand | 7 pas, SLS, HK|
|'06 LR3 HSE Luxury | Chawton White | Cold Weather/Adaptive HL/RSE/Running Boards | '14 "blackout" LR4 tail lights, 2.5" lift rods, 20" black/machined stormers, 275/55/20 Falken Wildpeaks
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| 5th May 2016 1:43 pm |
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