Increased diesel knock

[simon987]

Hi, I have a 53 plate 2L DTi with 105K on the clock and wondered if anyone has had a similar problem. About 2 weeks ago I did an oil change and since then I have had what I can only describe as an increase in diesel knock level. This is the first oil change I have done on the vehicle - usually have it done at a local garage and they used 5W40 Castrol Edge oil. I used Mobil 10W40 semi synthetic.
The symptom is that at tick over and up to about 2000 revs the knock seems to be much louder than it was. I've tried cleaning the EGR (usually do this every 6 months , used drivetrain top end cleaner in the oil and injector cleaner in the fuel - but still this louder knock. Also can't detect any leakages from the injector run off pipes or any splits in hoses. There's no noticeable changes in fuel consumption, engine temp, still accelerates as before, no additional smoke, etc.
Any suggestions?
Thanks.

[m8internet]

When you filled it up, did you recheck the level with the engine warmed up after 5 minutes?
Did you fill to the MIN or MAX?
Is the noise excessive?
Does it change as the engine warms?
Did you use a flush agent at this latest oil change?
Did you examine the removed oil?

[simon987]

I did check after 5 mins (and miny times since) and the oil level is on MAX.
Nosie is certainly not excessive - local mechanic friend thought it sounded a little noisy, but heard many Ford's with similar mileage sounding a lot worse. It's more the change in level that worries me.
It doesn't seem to change as the engine warms, nor when fully warmed.
No flushing agent used.
I didn't inspect the removed oil but did tip it from the catchment contained into an old oil container and didn't notice anything unusual.
Also, this morning on a short trip to the local shops the louder noise seems to have gone again. I do remember this happening last week too, but it back next time I started the engine. It was this that made me check all pipes etc for an intermittent leak. Will see what happens next time I go out.

[m8internet]

It's probably swapping from synthetic to semi-synthetic oil that has caused this, swiping the old oil that has adhered to the surfaces
The new oil basically is not lining the metal surfaces, hence the increase in noise

Monitor this over the next 1000 or so miles, I am fairly confident you will notice the noise reduces (as the oil darkens) with use

[the-wizard]

I shouldn't worry to much, I only use to put comma turbo diesel plus 15/40 from Morrison's in my di & dti's, I gave them some stick & all were 130k plus running 100% fantastically when sold (wish id have kept them a lot longer), People tend to worry but just regular oil changes do the biz for the every day user.

[macdad]

You say that you have used top end cleaner,and injector cleaner before changing the oil,this is 100% cause of the knocking mate,the cleaner will have stripped some of the old oil off the hydraulic tappets,you will find over time that the knocking will disappear.

[simon987]

I put the top end cleaner in after the oil change as it was after I replaced the oil it sounded noisy. So the extra noise was there before I put the cleaner in, adding it doesn't seem to have made any difference. The knock does sound more top end, so may be it is a bit of a sticking lifter.

[simon987]

Well it's been over 4K miles since the oil change and only difference I've noticed is that the problem does sometimes go away - that is when starting from cold sometimes the knock isn't there. But when I stop at my destination and then re-start, it usually comes back. Tried more injector cleaner and valve train cleaner with no effect. Finally changed the oil back to fully synthetic - but still no difference! Seems the oil change was a red herring...
So started looking for other reasons - wondered if it was a fueling issue, so cleaned the MAF & Boost Sensors - again no difference.
Had a chat to a mechanic at the local dealers, he was quite helpful, either suggested a minor air leak in the inlet or may be a mechanical problem. Suggested I bring the car in for them to diagnose but did say it could be expensive - yeah right! Looked but not been able to find an airleak, so wondered if it could be something like a camshaft or crank problem.
BUT another develoment, about 2-3 weeks ago noticed a bit of clutch slip under heavy load in a high gear. It's been slowly getting worse... so could this be the dreaded DMF breaking up and taking out the clutch? Could this be causing the knock I've been hearing? I read on here that the DMF on the DTi can be harder to diagnose...
Anyway been phoning around the Southampton area for a replacement - ignoring the solid flywheel conversion the best price I've had is £950 - anyone know of a cheaper place to get it done?

[peadar]

I done the wifes dmf at xmass it never slipped but the flywheel was gone you might just need a clutch plate but some would say to change it all when you have it stripped down , the noise could be the inlet manifold
gasket blowing internally which i have read on here before
the price you got isnt bad i paid £650 and that was no vat and doing it myself

[simon987]

Well it's been nearly a year since my knock noise started, I've had various mechanics, injection specialists and a pump technician listen to the engine knock and no one has come up with an answer. The noise hasn't got any worse and the clutch hasn't been slipping any worse either. That was until last weekend when, on a trip to the local supermarket, there was a funny fluttering noise from the engine on accelarating which quickly got louder and, when I pushed the clutch in, the engine stalled.
I pulled over and tried to start the engine - all that happened was that the ignition lights all went out just like the battery was flat. I engaged 2nd and rocked the car, then turning the key did manage to get the engine to turn, but there was a nasty sounding grunching noise. Got the AA out, the guy put a boost pack on and turned the key - not a good sound at all! He said it sounded like major engine damage.
Got towed home and then to the local mechanic - he took the sump off to find a loose bolt in the bottom and... a snapped crackshaft! Piston 1 and 2 were moving separately to piston 3 and 4. Not sure if the loose bolt was anything to do with it, it doesn't appear to have any damage inflicted on it.
Well car is now on 120,000 miles, don't know what other damage there is... so not going to repair. So going to stick it on Ebay for spares...