Yes, low revs under slight load, barely any throttle opening can exacerbate DMF rattle, usually in the higher gears though, say slowing to 30mph, an old DMF has you changing down earlier than you might otherwise but it gives it an easier time.

 

If you have just done some work then theres a good chance it may be related so for you thats a good thing.

 

You can usually feel a failing DMF by kickback through the clutch pedal under certain conditions.

Knowledge and experience much appreciated @J.R.. 

14 minutes ago, Graham Butcher said:

Just a thought, but are you certain that the timing belt and water pump has been changed?

Belt was done in 2020, but only 10 or 15k miles ago. Can't see it running as well as it did straight afterwards if there was a timing issue.

The other sign on higher output/higher revving engines is very loud knocking/clattering at high revs, like the sound the tractor pulling rigs make before they explode 😁

 

The 105hp engine probably wont rev that high, mine was pretty silent, no signs of any DMF problem until I had it remapped then it sounded alarming at wide open throttle high rpm but silent when driven normally.

 

When I changed the DMF during the clutch slave cylinder job it was and remains refined at all rev ranges.

115bhp I'll have you know. 😆

Not sure I'm brave enough to take it to high revs just now. 

Supposed to be driving to Bassenthwaite ( ~280 miles) with 3 passengers on Thursday. If it plays up again between now and then I think they'd better take their own vehicle.

 

Have you scanned it to see if there are any logged injector codes? Oil ingress into the injector plug and socket and general breakdown of the wiring and connectors under the rocker cover could have caused a misfire.

 

 

 

 

Good shout, thanks @SuperbTWM. I haven't, but will right now I think.

No faults logged in engine ECU. Reassuring, I guess; should have thought of that myself, but grateful for the suggestion.

 

It did behave perfectly on both commutes today. I tried to recreate the slow-moving traffic queue by going the same way at the same time, but of course the traffic was flowing sweetly for once. 😆

 

Big test tomorrow, Bassenthwaite or bust... sounds a bit like a film title.

1 hour ago, Breezy_Pete said:

Big test tomorrow, Bassenthwaite or bust.

I'll be about The Wirral tomorrow so wave as you go past

 

1 hour ago, Breezy_Pete said:

No faults logged in engine ECU. Reassuring, I guess; should have thought of that myself, but grateful for the suggestion.

 

It did behave perfectly on both commutes today. I tried to recreate the slow-moving traffic queue by going the same way at the same time, but of course the traffic was flowing sweetly for once. 😆

 

Big test tomorrow, Bassenthwaite or bust... sounds a bit like a film title.

 

The only lake in the Lake District. 

3 hours ago, Breezy_Pete said:

Bassenthwaite or bust

Wagons' Leap (M6 Thelwall Viaduct northbound) is now clear.  I was past there this afternoon and there were no lane closures or holdups.

 

I gather the wagon driver (pilot?) is OK apart from some cuts & bruises but I wonder if the rescue services are looking for his parachute?

 

Oh and avoid the M6 J28-J31 anywhere near rush hour - unless you like studying grass growing on the embankments, that is.

Edited 2 October, 20241 yr by MikeTheThinker

7 hours ago, Breezy_Pete said:

Bassenthwaite or bust... sounds a bit like a film title.

"Withnail and I Part 2:- Bassenthwaite or Bust".

Bassenthwaite it was. 

 

Very smooth, easy and comfortable. The M6 was even almost roadworkless, which was astonishing.

 

Just done a couple more round-trip commutes of 45 miles and finally filled up this morning with about 50 miles range still showing. 

705 miles from 62 litres, about 51.5mpg.  Not that great, but not terrible either.

 

Discovered a '2 hrs' message pops up on the dash to remind you to take a break, which I didn't initially know how to cancel (other than by taking a break).

Then on the way back found the button on the end of the wiper stalk that lets me cancel that and view all the trip/speed/mpg data, which I hadn't previously discovered. Thought it just always displayed miles remaining. 😁

 

Very comfortable; no complaints either way from me, my adult passenger, nor either of his teenage kids from the back seat.

 

Trouble I'm having now is the prospect of shifting the Polo on, when I know that it's 'good enough' for me, has negligible repair costs and everything currently tip top, except the saggy roof lining. 

 

Versus the A4 with known suspension work needed (front upper control arms including infamous pinch bolt) unknown flywheel/clutch/turbo condition etc. 

Hurting my brain a bit.  😆

51.5mpg is pretty decent over your first proper fillup and having done some work on it too. esp if you were motorway bumbling for a decent stretch of it too... 

my shiny new work van with 6700km up on it since July is only averaging about 45mpg... even if its mostly the same 50miles of motorway, thats pretty crap, more so for 1.5 diesel..

7 hours ago, Breezy_Pete said:

 (front upper control arms including infamous pinch bolt)

 

Still have nightmares about the one and only time I've had to remove one of these!

 

1 hour ago, SuperbTWM said:

 

Still have nightmares about the one and only time I've had to remove one of these!

 

Seen about 10 different methods in various YouTube vids, all look hard. 😆

Can't remember if the A4/Passat has to have the subframe lowered if you want to remove the lower rear suspension arm, the bolt doesn't come all the way out without doing this. That might be the A8 though as I can't remember lowering the subframe, just remember seeing it mentioned somewhere.

20 hours ago, Breezy_Pete said:

Seen about 10 different methods in various YouTube vids, all look hard. 😆

 

I've only ever had to do one, on my B5 Passat.  Psyched myself up for it over a couple of days, and read lots, which just added to my angst.  Showed it a hammer, and it all but fell out 

 

Gaz

On 01/10/2024 at 19:34, Breezy_Pete said:

 

Are those the circumstances when a DMF would clatter if everything was cold?

Don't like that idea much.

Any thoughts, pretty please? 

 

Hope you are enjoying your A4 Pete ....  

 

One of the best, certainly one that I have been most happy with was my A4 2.0T (yes, it had a red T, Lol)

It was only just 3 years old when I purchased it, with one owner and circa 40K miles though.

200ps and similar torque figure to a similar sized diesel engine. Brilliant.

 

Years ago I drove an Audi 80 Sport with 150,000 miles on the clock that we had for sale at the garage. It was faultless.

 

Anyway, just to share my experience regarding the DMF on my long possessed but recently sold, 2005 Octavia 1.9pd

 

When I test drove it back in 2011, I noticed a distinct rattle most notable from just behind the nsf wheel, so I asked the salesman (Premier Motors in Derby) to look into it and report, before I could agree to the purchase.

He shouted to a guy (he knew him) next to his sales plot to come over for advice.

The guy immediately said that it was the DMF.

Surprising to me they agreed that they would get a new one fitted. I said that I wanted it done at a Skoda garage.

I said that I would pay an agreed extra amount for this to happen (this way I knew it had been done, and properly too) so they agreed.

 

The invoice showed £1100 ish, (which I believe was ott) however the job was done and I had the car for the next 13 years without any drive, clutch or gearbox DSG issues. (and shhhhhh, I never serviced the gearbox and it remained faultless)

 

I was well happy with the purchase but I told him to look at prices of T4 Transporter's and get real with his offer for part exchange.

He upped it by £1000.  ............ He was a lovely fella, to boot.

 

I'm not sure if it is the same engine layout as the Audi though ?????

 I'm guessing yours might be a manual gearbox ????

 

Hope this helps. 

 

Edited 13 November, 20241 yr by Tilt

Thanks for the info @Tilt.

 

Yep it's going very well so far, ta.  No repetition of the horrible rattle.

 

44 minutes ago, Tilt said:

I'm not sure if it is the same engine layout as the Audi though ?????  No, it's longitudinal in the Audi, took me a sec to work out what was going on, the first time I looked under the bonnet!

 

 I'm guessing yours might be a manual gearbox ???? Yep, 5 speed manual

 

Things I've done recently: 

 

Cleaned out  intake manifold.  Wasn't as bad as I expected.

 

Fitted a new genuine engine air filter and gave the MAF a clean, initially just squirting some isoprop across the film, then with an aerosol of 'proper' MAF cleaner lent by a colleague a couple of days later.  I could convince myself that it goes better and chucks less smoke out of the back as a result of these things. Filter wasn't at all grubby though TBH.

 

Attempted to get one of the pinch bolts moving, and briefly succeeded, but then it jammed up again half a mm to the left. Took a lot of getting back to 'done up'. So I ran away and left it for another day/month/year.

 

Latest game is to see what journey average mpgs I can get on my commute.  It's probably near ideal, in flowing, but slowish traffic at 7am, maybe 45mph most of the way. I've finished the journey with an indicated average for the journey of 60mpg a couple times in the last week or two, which I suspect isn't quite real, but it's pretty good. For as long as I have to do twenty-odd miles twice a day, it might as well be as efficient as I can get it.

Always seems to be slightly worse on the way home. Prevailing wind effects, and/or possibly a steep hill I go up very early in the outbound journey, bringing temps up much quicker than on the flat start of the return journey?? 

 

 

 

Hit an indicated 62mpg at the end of this morning's commute, new record. On ordinary Tesco diesel too. 

Tail wind, I feel sure.

 

In other news. Minor collision one evening last week, luckily going rather slowly down a hill in a 20 zone. Thought for a horrific half-second that it was a dog that had run out in front of me.

The thing got up and made it across the rest of the road, and stood on four legs on the pavement,  now looking very Muntjac-like, fortunately. 

Muntjac 1, OSF foglight 0. 

 

Could have been so much worse.

 

Put a nearly new tyre sourced from ebay onto my spare wheel, then swapped it onto car on Saturday,  I now have four tyres that match, albeit not brilliantly on tread depth uniformity. 

Spare is a full size matching alloy.

 

Had reason to move the car down the gently sloping driveway yesterday (away from house) without starting it up, and noticed two things while doing so.

1. It's bleeding heavy to steer even slightly minus the PAS (engine driven hydraulic).

2. There was zero residual servo vacuum. Double-checked that just now, that can't be right, right?

 

 

Edited 2 December, 20241 yr by Breezy_Pete

I think that your 62mpg is not a fluke because of a tailwind, I have had 67mpg sometimes if the conditions are right, just need to be relaxed in your driving style with very gentle right foot and let the engine torque waft you along. My son has purchased himself a 3-year-old Audi A5 special edition and went from Chelmsford upto Old Trafford and back yesterday on a single tank of diesel, 40 litres his tank holds and in his old Ford Focus diesel he always used a full tank of 60 litres so his A5 averaged 59mpg. Needless to say he is very pleased with that and his focus was manual and the A5 is DSG and 2 litre with twin turbos.

 

Are you sure you PAS is hydraulic, I think it possibly electric as is mine and so have all the Superbs and Passats before them, so I doubt yours is any different.  I think it is normal as well for your brakes to have no residual vacuum without the engine running. 

20 minutes ago, Graham Butcher said:

Are you sure you PAS is hydraulic, I think it possibly electric as is mine and so have all the Superbs and Passats before them, so I doubt yours is any different.  I think it is normal as well for your brakes to have no residual vacuum without the engine running. 

I've owned several B6/B7 A4/S4/RS4 and they all had hydraulic PAS.

Very sure Graham.

 

@PetrolDave what do you think about the lack of residual servo vacuum, please?  (On second thoughts, perhaps you don't drive diesels, going by the username. 😆)

Just been examining pipework and the one non-return valve I could get to reasonably easily (down near turbo actuator), but nothing found to be amiss so far.

Edited 2 December, 20241 yr by Breezy_Pete

51 minutes ago, Breezy_Pete said:

Very sure Graham.

 

@PetrolDave what do you think about the lack of residual servo vacuum, please?  (On second thoughts, perhaps you don't drive diesels, going by the username. 😆)

Just been examining pipework and the one non-return valve I could get to reasonably easily (down near turbo actuator), but nothing found to be amiss so far.

Oh yes, my bad, I forgot your car is a 57 plate, they started switching over to electric in 2012/13.