 | Home > Puma (Tdci) > can sound like bag of spanners when cold accelerating |
 
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| vaucluse Member Since: 04 Feb 2012 Location: SE London Posts: 185  
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Hey,
Does your engine sound reasonably quiet when started from cold and then the bag of spanners starts after approx. 7-10 mins and then more or less disappears when fully warm? Mark |
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26th Sep 2016 4:55pm |
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| neverin Member Since: 26 Sep 2016 Location: worksop Posts: 47  
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Hi Mark, it only makes the bag of spanners noise when under load, and can be heard from first set off and also over the first 2-3 miles if under load. Idling and revving the engine has no effect.
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26th Sep 2016 6:08pm |
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| vaucluse Member Since: 04 Feb 2012 Location: SE London Posts: 185
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Ok, double check if it's a little better from start with a noticeable increase in noise after a few minutes then it'll be the VCV that'll need replacing otherwise if it's the same from cold throughout the warm up then it may be down to the piston cooling jets issue - hopefully not the second scenario.
Best, Mark |
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26th Sep 2016 6:55pm |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 16868 
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A faulty VCV could cause this at any time, hot or cold, immediately from start or after a while. Don't rule out the VCV.
It is unlikely though not impossible to be the PCJ problem from the symptoms you describe (and based on the fact that your engine hasn't disintegrated by now). |
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26th Sep 2016 7:33pm |
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| Cupboard Member Since: 21 Mar 2014 Location: Suffolk Posts: 2971 
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PCJ issue was fixed by 2010, I think anything made from 2009 onwards.
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26th Sep 2016 7:39pm |
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| neverin Member Since: 26 Sep 2016 Location: worksop Posts: 47
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What is vcv?
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27th Sep 2016 8:23am |
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| neverin Member Since: 26 Sep 2016 Location: worksop Posts: 47
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Sometimes when the engine is warm and it's put under load there seems to be a bearing type rattle but not the bag of spanners, that seems to be more when it's cold
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27th Sep 2016 9:09am |
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| X4SKP Member Since: 29 Nov 2013 Location: Berkshire Posts: 2287 
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That would be my question too... 
Still none the wiser after... (i'm linked to the thread now so hopefully someone will come along with some insight) Mine has this characteristic (slightly) also, if you accelerate slightly harder than gentle whilst the engine is in the process of warming up...it 'audible complains'...back off OK...warmed up OK...so genitally does it until all up to temperature has become 'a thing' probably good practice too. I also read that for diesels it is better to start and then go i.e place the engine under slight load...thinking is this takes up play (slack) within the engine components that would otherwise just 'rattle around' if left at tick over...some logic there I can see...but not sure (any observations D2N?) Can't see that this wouldn't also apply to a petrol engine, maybe even more so as diesel is essentially an oil,... I mention this as with this type of noise issue there could be the temptation (not saying it's bad) to leave the vehicle ticking over to warm up (the engine) before driving (the vehicle is not insured with some companies if left running unattended...  ).
So a Puma 'Characteristic'...or something going 'south' (an engineer would say that 'hard' mechanical noise is a sign of something not running as it should... so in the process of failing sooner than it should...or already failed)  SKIP
https://www.defender2.net/forum/topic83242.html |
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27th Sep 2016 9:50am |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 16868
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The VCV is the "Volume Control Valve" (although you will find it called various other things) which fits on the mechanical combined HP/LP fuel pump used on the 2.4 TDCi engine. It regulates the flow of fuel from the LP side of the pump to the HP side under ECU control according to the demands of the engine, and consequently is the primary device for controlling the fuel pressure in the engine's common fuel rail. On the 2.4 Puma the fuel rail pressure, although monitored and regulated by the ECU, is not well reported as far as DTCs (Diagnostic Trouble Codes) are concerned, which means that a faulty VCV can cause all manner of wierd symptoms without any fault codes being raised. Generally if you have any kind of rough running, fuel starvation, misfiring, unusually rattley injectors, hesitation, failure to idle, or similar symptoms and there are no fault codes stored in the ECU, then suspect the VCV. It can cause all these and more, but seldom will cause a fault code, whereas most of the other things that cause these symptom will leave a DTC. It is the absence of DTC that tends to point to the VCV. It is Item 1 in the photo below. Last edited by blackwolf on 27th Sep 2016 10:24am. Edited 1 time in total |
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27th Sep 2016 10:02am |
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| X4SKP Member Since: 29 Nov 2013 Location: Berkshire Posts: 2287
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blackwolf....
very interesting...I get none of the other problems you mention...nothing other than a slight audible 'complaint' noise if the engine is 'over worked' during warm up...<10 minutes. I'm actually really impressed with the 2.4 Puma Engine (and gearbox so far) she runs really well, 30K just up and it's feels great to me...I know generally you read about the problems being experienced and I know I drive along with 'one ear to the ground' sometimes... but so far another day and no issues... 
The VCV if not 'delivering' what it should, and leaving no fault codes (I have the scangaugeII fitted and nothing logged here as you say) may be worth further investigation... Is the VCV it testable... or is it
'swap over' to prove faulty...
Thanks again for the feedback.. SKIP https://www.defender2.net/forum/topic83242.html |
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27th Sep 2016 10:21am |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 16868
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Remember that you may get any of those symptoms and more, but not necessarily all of them.
The VCV is not testable, it is a throw-away part (it costs around 100 and you will need to carry out a "pump relearn" or recalibration after fitting a new one using a suitable diagnistic tool. It is incredibly difficult to find any kind of diagnostic evidence with any tool of a malfunctioning VCV, though you may notice that the fuel rail pressure is unusually low on sudden aceleration. However, since it is alomost impossible to know what the fuel rail pressure should be at any time, it is hard to determine that it is wrong. The best bet in my view is check for any other obvious faults first and check for DTCs, and then if there are no other obvious faults and no DTCs, replace the VCV. This will either solve the problem or rule out the VCV as the cause. If the latter, than at least you have a spare working VCV for the time when it does eventually fail. The VCV is also very easily damaged by dirt, contamination, or water in the fuel, and ii is almost certain that if you do have any of these it will fail not long afterwards. |
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27th Sep 2016 10:31am |
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| custom90 Member Since: 21 Jan 2010 Location: South West, England. Posts: 19560
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In depth VCV details may well prove valuable to any of us at any time.
So thank-you Blackwolf and Lorryman100 on here for such in depth explanation and details regarding technical items. Diesel$ Live$ Matter. ⛽️🛢️👨🔧🧰⚙️ RED, WHITE & BOOST! 🇬🇧 |
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27th Sep 2016 10:32am |
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| Pinky Member Since: 09 Jun 2016 Location: England Posts: 205  
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Is there any special instructions for changing the VCV other than a re-learn, as I have one on order for just the symptoms described here.
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27th Sep 2016 1:42pm |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 16868
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It is covered in the Puma 2.4 WSM of course, but in essence, no. It is awkward to get at, and if you can find a mutant child with tiny hands and exceptionally long arms, preferably with an extra elbow joint, it would help.
There is an O-ring and a gasket which can fall out of place so you need to be careful, and you need to ensure scrupulous levels of cleanliness - a speck of dirt entering the VCV or fuel pump will cause problems. Once you've phsically changed the valve, follow the procedure prompted by the test tool to recalibrate the pump, but make sure that the engine is at normal operating temperature when you do this. |
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27th Sep 2016 1:47pm |
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