Diesel Knock - Driving me insane! HELP!

[lockettben]

Evening everyone,

This will be a long one so grab your popcorn or crack open a beer.

So very long story short, I have a CFCA 180 engine that has had the following work done on it:

- Brand New Genuine crate engine
- New DPF & Lambda Sensor
- New Injectors (came on the engine)
- New EGR cooler (Came on engine)
- Recon full turbo unit from Darkside
- Tafmet EGR Emulator and delete (to stop it going pop again)
- New Clutch and DMF
- ECU Reflashed with factory latest flash


It's done around 1600 miles since the above was carried out. But from day one it has had this rattle/diesel knock.

The scenario is, on idle it very rarely does it, only time it has done it was when it got MOT'd and was sat idling for long time. It does it when under load, I you build the revs up very slowly it doesnt knock but I you accelerate even slightly it knocks/rattles. It will also stop/start knocking mid acceleration, for example if you accelerate it will knock -> go quiet -> knock.

Things I have tried/tested:

- Timing - All ok.
- Injectors were swapped for a known working and tested set - programmed in with VCDS
- Fuel Rail pressure actual vs demanded - Nothing abnormal
- Tafmet EGR emulator removed and EGR unblocked
- All learned values reset and relearnt amongst all the above changes


I've ran out of patience and ideas. Other than condemning the new crate engine im not sure what to test/check next.


If anyone has experienced this before or has any ideas what to check next it would be greatly appreciated.

Thanks
Ben

 

[lockettben]

We shouldn't assume the injectors are good simply because they are new.

The ones I swapped them with were tested before I fitted them. To take away any assumptions.

 

[Sasquatch]

Sorry, was editing my post and somehow deleted it like plonker!

 

[darkman884]

so what havnt you got,,,,,
smoke , blue or grey or black
hesitation
loss of power
overheating
heavy vibration
quality engine insulation etcetc ??

is it not just normal compression engine noise?

can you get a video obviously with sound and put it on youtube and put a link up?

 

[darkman884]

are you certain it is engine related and not the clutch/dmf?

 

[Sasquatch]

I was going to ask do you by any chance have a recording of the phenomenon?

 

[lockettben]

so what havnt you got,,,,,
smoke , blue or grey or black
hesitation
loss of power
overheating
heavy vibration
quality engine insulation etcetc ??

is it not just normal compression engine noise?

can you get a video obviously with sound and put it on youtube and put a link up?

Thanks

No Smoke at all.
As far as I can tell no hesitation
Power feels ok, anecdotally it feels less powerful than before the engine replacement but that may be just me.
No overheating
No heavy vibration
I installed the engine so as quality as I can get

I drove a 80k CFCA to compare and it was silent compared to this, deffo sounds more than normal noise, sounds like an old school diesel.

ill try and get at least an audio recording of it tomorrow.

It doesn't sound like clutch/DMF, but thats more as it sounds like diesel knock.

 

[lockettben]

I was going to ask do you by any chance have a recording of the phenomenon?

ill try and capture one tomorrow. Il mount a mic under the bonnet hopefully.

 

[Sasquatch]

Is it timed up right?

 

[lockettben]

Is it timed up right?

Yeah, triple checked it.

 

[darkman884]

whats the engine oil level at?
could you squeeze another litre in it for example? and still be safely under the MAX?
just putting a noisy tappet out there ? due to oil on the minimum side?
worth a check

 

[PhillH]

This could be totally unrelated but I have a 1.6tdi Audi A1. When it wants to regen I get diesel knock as though it is throwing a load of fuel in to get the temperature up and while it is regenerating is can not be driven at low revs over wise it “kangaroo’s”. Keep the revs higher that 1500 rpm and it is fine. One it’s completed the regen it’s back to normal. Have you noticed your revs picking up at all?

 

[darkman884]

was it filled with the correct grade oil?
seems how its a brand new engine,does it need a 500 mile running in oil change etc etc?

 

[Dellmassive]

Have you got access to VCDS?

@mmi is expert at t reading block maps

 

[lockettben]

was it filled with the correct grade oil?
seems how its a brand new engine,does it need a 500 mile running in oil change etc etc?

Yeah it is just below max with VW recommended grade (can’t remember which one)

 

[lockettben]

Have you got access to VCDS?

@mmi is expert at t reading block maps

Yeah I have access to vcds and Abrites and ODIS if required.

 

[Sasquatch]

Yeah it is just below max with VW recommended grade (can’t remember which one)

Probably unrelated to your issue, but these engines like their oil no higher than halfway between the marks on the 'stick.

 

[DXX]

But from day one it has had this rattle/diesel knock.

I have a CFCA, it’s a well balanced engine and with the low RPM power from the biturbo it accelerates very smoothly.
As far as I’m aware there is at least one knock sensor as on the later engines, if there is an ignition issue it should generate a fault code.
If the noise has been there since day one I’d make a guess and say there’s something not right with the installation, a component loose or knocking.

 

[darkman884]

ok , so reset the van engine, to baseline ,( im reading it that you have done an egr delete etc)
i mean remove the modulator and refit the egr system ,
this will, lf nothing else return about 10% of the low down revs torque you will have lost by mapping it out ,
see if it still has the same symptoms .
go from there

 

[DXX]

My CFCA runs noticeably better with the Tafmet kit fitted.