Stagn8

Coincidently, have just towed the van down to Blandford Forum. which for me is M3. A303, A354 and the car behaved impeccably, it was quiet relaxing! Not a hint of waywardness, so, for me it does confirm that road surface is the problem. Thanks for all the comments, it has been interesting, particularly the comments from Stevey Y. Cheers all.

Thanks for a this information Steve, it is reassuring to have a bit of background on why it happens, I was finding it a bit stressful not understanding the root cause. For others not experiencing it, it is only under particular circumstances, very poor surface and heavy loading. Unless you replicate the situations Steve and I describe then hopefully you won't ever get it.

Thanks Steve for your information. Also pleased you have noticed the same thing on the concrete sections of the M25 (have also noted it on motorways in France) I guess as a cab driver you were often heavily loaded as this is when it is noticeable, four adults in the car. The weight in the back of two adults and particularly when towing (about 80kg downforce at the very back of the car) will certainly alter the loading at the front wheels and I imagine could quite easily alter the way the steering reacts on certain surfaces, particularly if it designed to be pin sharp, leading to these tugs on the steering wheel. I am going to get four wheel tracking done just for ‘an abundance of caution’ and the fact that the rear suspension is adjustable as wondering if the extra squat caused by the weight causes some unwanted movement in the rear suspension, impacting on the front end. Not sure when I will be repeating the fully loaded trip on the dreaded M25 to see if there is any improvement though.

It’s due an interim service so will get my local specialist to take a look and see what they come up with.

Think you are getting a bit hooked up on this budget tyre thing Gareth. They are not the most expensive at around £100 a corner but after 4,000 miles they still have 8mm of tread, so somewhere under a mm of wear.

No, same between 50 and 70mph. Only noticed it on motorways so couldn’t say if it does it below 50mph.

I agree Gareth, not keen on getting the tracking done as I not aware of anyone around my area who isn’t a multinational. Not saying they aren’t any good, more that their heart isn’t in it! Changing tyres over is a good call, as I believe it is something marginally different somewhere as it only seem to happen when heavily loaded and certain surfaces. Took four people ( including me😀)to Eastbourne on Friday, M25, A22 and the car was scary on the M25 concrete section. Came back via Brighton and A23 and it was the usual comfortable drive. Seems the road surface plays a big part in this, but the car should be able to handle it, never a problem on other cars I have driven on the same surface. Looks like there is nothing definitive and probably just something on my car, so a bit of experimentation required 😕. Thanks for the help and if/when I find something I will update the thread.

Tyres were new when I bought it at 18,000 miles so only 4,000 miles of wear and nothing noticeable on wear accross the tread. If you look at the Tyre pressure sticker there are three settings, 'comfort' being the first and lowest setting. Tyre pressures are spot on for normal loading and use. The inconsistent steering isn't a pull in one direction, it needs constant input from me to keep it online. Normally a motorway should be relaxing with minimum input on the steering but I am having to make small adjustments all the time. It only seems to be on certain road surfaces and fully loaded.it I'll get the tracking etc checked as it seems a good starting place. Do I need just the front or four wheel alignment? Not sure how much is adjustable at the rear. Thanks all.

Checked the tyres against the sticker on the door and they are as specified, they are also XL. So, all good there. On line reviews for the tyres aren’t exactly glowing but equally no one is flagging them as terrible.

H’mmm good thought Gareth, not pumped them up from normal on this trip, though they are set to the mid level rather than comfort, didn’t really think of it as it hasn’t been important on any other vehicle I’ve had. However, I was towing a caravan with it in France earlier this year ( that means an extra 80kg loading at the extremity of the rear of the chassis) and had the same problem, and I know I had the tyres at the correct pressure for maximum loading, as recommended in the handbook and door plate. In case it is important, it is on 19” wheels which seem to generate a lot of noise at the back over bumpy surfaces. It does seem that road surface plays a part but, what impact does tracking have, I have no idea what Audi recommend but I am under the impression it does have an impact on straight ahead stability, small amount of toe in to help with tracking in a straight line. Load rating is 96y which is 730 kg I believe. PS. Not too Far East, Czech and part of continental, so not all bad 😀.

Can anyone shed any light or have suggestions on the following issue please. Audi A5 cab Quattro. When driving on a motorway fully loaded, four adults that is, the car just wanders about the road and needs constant steering input, sometimes a bit more than a nudge. It is particularly noticeable on the concrete sections of the M25 but also happens on other motorways (including in France). It is much less noticeable solo or two up. Car is low mileage (22,000) and has new tyres (came with four new Bravuris 5HM 🤷🏻‍♂️🤷🏻‍♂️ when I bought it) just passed it’s MOT which suggests none of the myriad of bushings were looking nasty. It does seem to me that certain surfaces upset the car but should it be happening, or could be as simple as tracking? Any thoughts appreciated.

You may want to google FTC before you part with any money, as very few are convinced that they are any thing other than ‘snake oil’. As the old adage goes ‘if it seems too be good to be true then it almost certainly is’. They have been around for donkeys years, previously I think they were called Brockets and came in a small bag. They didn’t work then and they don’t work now, a few scientific studies are around to prove it. As ever, your money, your choice but if you do get them try doing some reasonably challenging tests to prove or disprove their veracity. A few tank to tank mileage checks would be a good start.

I have bought exactly the same one and it is in the glove box ‘just in case’ as so far not had the problem 🤞🏻. I think the price is about right as if it is a pressure sensor all that’s likely to be in there is a sprung loaded bit of material which reacts to the vacuum generated in the servo and relays an ‘on’ message to an ecu to confirm the servo is operating. If the ecu doesn’t get the signal then it compensates by operating the abs unit, which we all know know can’t take fairly continuous operation. No idea how VAG justify their prices but the one I received has ‘made in Germany’ on it, so hopefully not been anywhere near China. Having said that, the Chinese are more than capable of producing very high quality parts if they want/need to and I am pretty sure all the German manufacturers have a fair smattering of Chinese parts made to their own exacting standards. ( Not sure what standards were being followed for these sensors though, pretty minimal ones I would hazard)

Rover used to have an optional auxiliary heater available on diesels which preheated the water so gave a warm start with instant defrosting and warm interior. They were diesel powered and available both with a timer or a remote system using a mobile phone signal. Could it be something along those lines?

Did have an imported Nissan Pulsar GTiR for a while! Looked pretty mean so just had boost adjusted to 280 bhp.