SEman

The car and caravan are always loaded in a similar manner with the nose weight at between 70-80kg and the car is certainly not overloaded. The car does exhibit the vibration when solo so it’s not just when towing. I’m coming to the view it’s the DMF on its way out. So I’m just driving it sensibly and keeping watch on it. Anyway the vibration is a second order problem as I’ve just had to drive 80 miles home with the ABS and ASC orange lights and a red warning all illuminated. And I thought these were reliable cars!

Yes my digital gauge can read koi, bar and psi. I use the kpi scale and cross check it with a Schraeder pencil gauge and a mechanical gauge too.

Not that I’ve noticed. When the vibration does occur I’ve touched the gear lever but it’s dead steady. Where might be the best place to feel for vibration on tickover?

I thought that i would post an update since I have towed the caravan some 600 miles during August. Solo the car has started to show the vibration when under some load like going up hill, but even then the vibration can only be induced by giving it some accelerator from around 45-50 mph and taking it up to over 60mph. It seems to come in around 2000 revs in 5th gear. The service manager at my local independent VW/audi specialist got i to do it, but it was over so quickly that he couldn't with any confidence diagnose anything. They put the car up on the ramps and gave the underside a good inspection but couldn't find annoying untoward. I have had the wheels aligned and it made no difference. Towing the caravan does get the vibration to happen more frequently but mostly on inclines as on the level it disappears unless I accelerate with the caravan in tow. Solo the car seems to be more "boomy" at lower revs. So that's about it thus far. For information when DMF does fail is it rapid and likely to do damage, or is it likely to be more gradual so that you can pull over, or as it worsens take it to a garage.

Oh cheers, the dreaded DMF the curse of the diesel as well as DPF -)

Thanks your experience sounds similar to mine. Solo the car drives smoothly with little drive train noise. I had thought of removing the Haldex fuse next time I tow to see what the effect is. The Haldex oil was renewed when the new pump was fitted. With other commitments I’m unlikely to tow in the next couple of months but will be having a wheel balance and alignment check soon.

I’ve been back through the service records and none show a diff oil change. The Haldex was done at 30k by my garage, and again recently after having the pump replaced. The DSG oil was changed on its fourth annual service in June 2014.

Thanks for the replies. After the bank holiday I will be taking the car for a four wheel alignment check. When it happened I dropped it into Sport mode which increased the revs and seemed to reduce it somewhat, but it was still noticeably there. I guess I could have put it into Manual mode. But even when it was in normal auto mode the engine was dropping to 5 or 4 gear so it wasn’t labouring at low revs. I should clarify there there were only two of us in the car with dogs and luggage and noseweight. So I calculated that as being equivalent to a driver and three passengers plus of course the caravan hanging off the back.

I have a 64 reg 170PS DSG 4x4 which has done 45000 miles. I bought it in March 2017 with 25000 miles on the clock, as the second owner and it has a full service history. I tow a 1300kg caravan and the car has performed very well. At its last service in February 2019 the diagnostics picked ups problem with the Haldex. Further diagnosis showed the haldex pump to be faulty. A new pump was fitted in April 2019 and the haldex fluid renewed. It has had an earlier Haldex fluid change whilst I have had it. Since the car has had the new haldex pump I can't say that i have noticed any significant difference in its sol driving characteristics. However last week when I towed the caravan since the pump had been replaced I noticed a thrumming vibration but only under certain driving conditions. If I was doing 50 mph on the flat and accelerated to 60mph then i felt a vibration cut in which ceased when the power demand on the car reduced. Similarly when coming to a slope say at 55-60mph the thrumming vibration would start but stop once the slope eased off. The car had the load equivalent of four 75kg adult inclusive of myself, wife, dogs and luggage. The caravan noseweight was 70kg include in the loaded weight. Tyre pressures were 280kpi rears, and 240kpi fronts. Tyre size 225/45/17 Michelin Cross Climates. Yesterday taking the caravan back to storage I accelerated from 30mph to 50 mph on a flat A road and no thrumming vibration. Tyre pressures 220kpa front 225 spa rear and with car unloaded. The previous services had been in September 2017 and June 2018 and neither showed any fault on the diagnostics and when towing the car was just as quiet solo as when towing apart from some increase in engine noise under towing load accelerating or on hills. Certainly the 4 wd system was working okay in September 2017 as I had to exit wet grass field with the caravan in tow and it all worked fine. I have taken the car to the garage that replaced the haldex pump and they carried out a diagnostic and it came back okay. Any thoughts on what might be causing the thrumming vibration would be welcomed.

Thanks for the info. What make of dash cam is yours? The makers were very helpful.

Thanks to everyone for your helpful replies. I've simulated a dash cam by placing my Garmin to the passenger side of the mirror and visibility is fine. So I think I will go ahead with the 512 G as they get good reviews for clarity in poor light conditions.

Thanks I have just found another thread where there are several fitting options and those who fitted the dash cam on the opposite side to the driver didn't have any problems with the dimming or wipers. The only disadvantage would be if you wanted to quickly save a recording. But Im not planning to save recordings of bad driving and send to the police. I am looking more for providing evidence should I be unfortunate to be in a shunt. Could be a double edged sword though!

What does the sensor control? Is it the wipers?

Thanks for that. It makes sense as I don't plan on touching it much once it is set up, and if have to do anything to it then the car will be stationary anyway.

Thanks thats helpful. My seat is right down on the stops and I find forward vision in the Superb good.