Same old thudding prob

[Tomoski]

Hello anyone who's out there at this ungodly hour. I have an Audi A4 1.8t Quattro cabriolet 54 plate with manual transmission. Still trying to get to the bottom of an existing problem of a dull thudding sound on initial take off. Its there in first and second gear and rides itself out by third. Coming from the nearside front wheel by my reckoning. Have taken it to both Audi Southampton & Audi Portsmouth for analysis but no conclusive results. Southampton suggested a replacement rear differential at the cost of £3,500 all told. Ive since been to independant transmission specialists who have had stethescopes to it and assures me its not diff. So here I am working my own way through by a matter of elimination. (The car is at the garage I bought it from at the moment - they have come up with nothing although they can hear the problem). When I bought the car it had 16 inch wheels on it which I duly changed to 18inch RS4's and put two new tyres on the rear and two very nearly new on the front. All the same size but not same manufacturer. Whaddya think? Any probs barking out there? Also I did not take into consideration any offset for the wheels. Does anyone know what offset my vehicle has? (Im in a bit of a grey area when it comes to offsets etc).

So here I am at work at 0315 and STILL trying to come up with some logical answer to the problem without hurling three and a half thou' at Audi!

Any comments greatly recieved..............

[dickymint]

Just a thought. Some years ago a friend had similar trouble. He found it was a flat spot on a tyre. Might be worth checking out. If its from the front offside, put the spare on and see if the noise ceases. Best of luck.

[Tomoski]

Thanks for that. I am on the case as far as the tyres go at the moment. Cheers for the advise, will let you know.

[devsgolf]

Did you check youre brake discs and pads (which could be loose and moving around), you're drive shafts and c.v joints (******* bearings) and it would be worth youre while checking youre anti-roll bar (bushings and drop-link connections, make sure there not loose). Hope this offered a bit of advice that you might have missed.

Good luck.

[Torque-Torque]

I am wondering if you resolved your problem. I have similar symptoms, having changed one rear driveshaft, regreased the CV joints and topped up the diff oil, there is a big reduction in the clunking noise, but it seems to be still slighly there especially when the car has covered some miles. It been going on for some 2,000 miles or more now with no significant deterioration, so I am curious about your conclusion. Thanks.

[no1mechanic]

hi if you wont a serious answer of what is up with your car i have always found the guys at IGS in eastleigh have always been the best for solving problems with VWs and AUDIs give them a call they are the best.

Unit 5 Stanstead Road
Boyatt Wood Industrial Estate
Eastleigh
Southampton SO50 4RZ
Telephone: 02380 629606
Fax: 02380 629329

[Captain Answer]

Is the problem only present under drive? I.e what happens if you take the car into neutral at a low speed and under breaking? IF it is underdrive then thats indicating a tranmission issue, if not only underdrive it widens the field

[Tomoski]

Hi Torque Torque,
This is a bit long but bear with it and hold on for the ride !!
I resolved this problem some time ago now. When I originally bought the car it had 17" alloys all round. I changed these for 18" RS Alloys and put on 4 X 235 40 18. A couple weeks later I had a puncture and took it to Hampshire Tyre Services (HTS) in Segensworth Industrial Estate and they duly fitted a new Continental Contisport Contact 3 235 40 18 @ £150. and off I went. At this time I was uneducated as to the delicate art of fitting different tyres to the same axle on Quattro's, but I did not experience any problems at this point. About a month later another slow puncture. Again I went to the same Tyre shop (HTS) and they condemned the tyre and I agreed to a new replacement tyre. They fitted another Continental Contisport Contact 3 235 40 18 @ £150. Again off I went.
Then the problems started.
I began to notice the thudding that I have explained in earlier posts. I booked the car into Audi Eastleigh, Southampton. I explained the problem only occurred when the car was warm. When I picked the car up I found out that it had been sitting in the compound all day and then they moved it into their workshop and checked it over and found nothing wrong but suggested rear brake discs and pads changing. Obviously they wouldnt have found anything as the car would have been stone cold while they checked it ! That cost me £100+ per hour. (As you know Audi are not cheap). I had the discs and pads replaced but still the thudding was there. Back to Audi for a second assessment. This time I took a technician out and demonstrated the thudding, his only comment was " How am I supposed to find that". Well at the end of that assessment ( Another £100+ per hour) They informed me that the differential was knackered and needed replacing at an estimate of approx £3,500. STAGGERING !! I went home to have a Jack Daniels (He always comes up with the right answer).

I decided to go back to the starting point and re fit the 17" alloys which I still had stashed. Another tyre specialist this time by the name of Stewart Sharp of Get-a-Grip tyres in Southampton (Number supplied on request) re fitted them but was convinced that this would not get rid of the thudding. BUT IT DID. We then inspected the tyres. THIS IS THE IMPORTANT BIT.
On both tyres supplied by HTS, it had it has the usual markings "Continental Contisport Contact 3 235 40 18" BUT on one it also had a small marking with "95Y" on it. The other had a marking of "RO1". I then went back to HTS Tyres and asked them if the two tyres were in fact identical. They said they were definitely identical and that the markings designated the tyre for a certain model of car, but reiterated that they were identical. I then contacted Continental Technical Dept in Germany and explained all the shinnanigans. They replied promptly and basically said that the RO1 was for RS6 and R8's and was specifically designed for prodigious power output and therefore should not be mixed with 95Y's as (Quote) " they can induce a handling imbalance" I took this e-mail directly to HTS Tyres. They then told me that they knew they were different tyres and told me when thy fitted them !! They did not. I asked them that if they knew they were different, why did they even try to fit a mismatched tyre as when I pay them its not just for their labour and supply, it is also for their professional advise. They could not answer that and after more wriggling they agreed to reimburse me for the mis matched tyre. I then went back to Stewart Sharp (Get-a-Grip Tyres) and he supplied all matching tyres, fitted them on my 18" RS Alloys and I have never looked back. CASE SOLVED.
Summing up -
Always use exact matching tyres all round on Quattro's.
Never use HTS Tyres of Segensworth as they are no expert tyre fitters and are of limited intelligence regarding specific requirements for certain vehicles..
Never take Audi's diagnosis as final and exacting. It appeared to me that if they could'nt plug it in to a computer and obtain a fault reading then they were ******* into the wind (with your money).
Always consult Jack Daniels for the best advise before making a decision!!

I hope this all helps and maybe saves you time and money in sorting your problem out.

Please let me know your outcome.

Rgds. Tomoski.

[tornadored7]

Hi Tomoski,

I don't have an Audi, nor even a Quattro/4 Motion. However, I am glad that in your case you very methodically got to the root cause of that quite delicate problem without succumbing to a dealer's expensive misleading diagnosis.

Even more, thanks for sharing that with us , since I am sure that will be useful to someone.

Regards,
TR7