Now at my whits end!!!!

[Andyh-R6S]

Having just got the UrS6 back from its MOT and oil Change service and an assumed diagnostic (as they did last time and found nothing!!) by the Garage who specialises in these types of cars, when first driven from cold everything is OK. Get it on the motorway 15 to 20 minutes later and the fun starts!

The car is now limiting boost most of the time to ‘1.2 to 1.3 bar’ (Instrument cluster boost gauge) and the car is really sluggish but every now and then it self clears itself and it’s off like the clappers. (It was not like this when it went in to the garage!!) Although it had a minor stutter before it went into the garage, which has been looked into in every way possible but nothing could be found when the car goes into the garage and it works OK!!!

I really need help here please as it’s not going back to people who do not understand what’s going on, I know how the car drives and what it does or does not do in this case and unless it dose a diagnostic run while actually being driven for half an hour with a laptop connected, I will get nowhere unless I can get more good help from all of you.


So:

First:
I have one of those fault readers (U281) with a ‘scart’ type connector for Audi cars. Where do I plug it in? Or does it need a converter cable to us it on a ’97 Ur S6’? (((The garage has done another full vacuum test and all is OK and it was supposed to be boosting OK but apparently the only fault logged was a ‘Knock sensor’ but when erased it did not do it again) If it is a knock sensor, can these bits of kit start to fail and cause slightly hesitant running but not loads of fault logs?) The garage also said the turbo was slightly noisy but I noticed that when I changed the boost hoses to Samco ones from the original Audi kit about a year ago. Putting your hand on top of the plenum remove most of the excess noise so I was putting it down to the silicon hoses not absorbing the noise like the Audi rubber versions?)


Second:
When the car is fully warmed up it does not always allow boost over 1.2 to 1.3 bar and as stated above it only had a slight hesitation before it went into the garage but flooring the throttle it was off previously. Now flooring the throttle does nothing when in limp home (I think?) mode comes into play. I cannot hear much turbo whistle and I must admit it really does not feel rough, it just obviously limiting the power. (No popping or banging. (I have been under the car and nothing appears loose, all looks OK and I have checked all the connectors, etc.))


Third:
If I cannot sort the issue, (Although replacing kit might find it but its going to be very costly and I do not want to go there) would a run with suitable software loaded into a laptop show up the issue and direct me or anybody to the primary cause of the fault? (Anybody close to Bexleyheath, England who knows how to use the kit and has it, etc?)

It really is a shame as the car runs very well most of the time, it’s just the niggling hesitation that I know it should not do, spoils the enjoyment but the latest garage debacle has left me fuming!!!

Sorry for the data dump and the obvious upset nature of the above but I am on the edge at the present moment. I just whish I could find somebody who knows the cars!!

Regards,

Andy H.

[Fat Audi 80]

I have speed read that, but I think you are already close with the issue of the knock sensor fault code. Have you thought about changing that first?

If the knock sensor is faulty that will defintely limit your boost and most likely when warmed up and wanting to give it some beans.

I am sure there will be others along soon.

I can sympathise, but don't worry, someone will have the answer.

(Have you thought of coming down to Billing, Northamptonshire on Saturday or Sunday. There will be a load of experts there drinking beer. We are bound to find something?)

Cheers,

Steve.

[UrS4boy]

Well it might truely be the knock sensor. However, I suggest pressure testing the intake tract (to check whether one of your Samco clamps is loose, etc) and perhaps, reading through this and trying some of the possibilities:

http://forums.audiworld.com/s4s6/msgs/115408.phtml

[spink]

you need one of these for the scanner

http://cgi.ebay.co.uk/2X2-Adapter-Ca...d=p3286.c0.m14

[Andyh-R6S]

Any more ideas?

I have just bought a couple off ebay, many thanks. (Bought two just in case they are too cheap and one fails) Should have them by Monday or Tuesday. Then I get the codes. To be honest I would like to come to the outing but I am preparing to go abroad again, so it’s at the wrong time and I cannot really start messing about with the car again. (I paid somebody to do that for me!!!)

Can knock sensors cause issues like no more than ‘1.3 bar boost’ and then allowing full boost but no fault in the ECU? If it is knock sensor on the way out, could it have caused the slight hesitation it’s had for the last two years? And not be found by the specialist garage I have been using? (Should I change both if one is defective? car now 11 years old)

The Samco’s, I hope not as it’s just been to the MTM garage to be checked for that but I will check all that tomorrow morning again and to be honest they were not loose before it went in as I checked them all. The coil packs (034 M’sport kit) are OK as are the plugs (Torqued down nicely and no signs of oil at the bottom of the plug tubes) and I have checked the MAF to turbo hose and there are no splits to the hoses and/ or the associated hoses and all clips are nice and tight. (MAF is new(ish) and was OK before hand. Lambda probe is also new(ish) and appear s to be OK)

The stupid thing is the MTM garage gave the car a clean bill of health and within ‘20’ minutes on the motorway this morning when it warmed up it had no more than 1.3 bar boost and it was in all gears, as it still did it when I came off the motorway. It did allow full boost occasionally but not consistently. (Allowing the car to cool down also helps the issue disappear slightly until it’s warmed up again)

I hate paying for something to be done supposedly properly and then to have all this. Apart from the MOT and the service, all it had was the slight hesitation I have been trying to get rid of for ages, now it’s a bag of poo.

Too be honest, the new ‘MAF, Samco’s, 034 M’sport ignition kit, lambda probe’ have made little difference to the slight hesitation it’s had. The biggest change came when I got rid of the Frankenstein wastegate top cover and put a standard one on. This got rid of the WOT higher rpm hesitation but then I got back an underlying low rpm hesitation but not at all like I had this morning.

I hate cars. Give me a camera any day.

[martinjs]

Whats the name of this MTM garage? where did you get your samcos from?

[Andyh-R6S]

I got the Samco's sent direct from Samco but paid for them through one of their agents about a year ago. They still look like new.

[Andyh-R6S]

Just pre-empting the fault codes

Where are the knock sensors? Are they easy to get at on an UrS6?

Many thanks.

Andy.

[Nuvo]

...and the MTM garage is where? Haywards Heath by any chance?

[Flat on my back]

Here and here...

Hth.

[spink]

QUOTE=Andyh-R6S;341468]Where are the knock sensors? Are they easy to get at on an UrS6?

Many thanks.

Andy.[/QUOTE]

much easier to do than on an S2

they look a bit different on turbo cars than those pics above though,they are black plastic and have a 10/12mm bolt that holds them in(very low nm to tighten them),can't upload a pic though

and for gods sake don't take the car back to those ****wits,pete berry at white cottage quattros near horsham will sort you out.

[UrS4boy]

Here and Here. Hth.

Beg to differ. Those look nothing like AAN knock sensors. Have a look at this:

http://forums.audiworld.com/s4s6/msgs/116988.phtml

[Andyh-R6S]

Memo Scanner lead has arrived!

Thanks for the picture; I have just printed it out.

I have had another good look and physical check round all the Samco’s this morning and all is nice and tight with no splits and to be perfectly honest the ‘whoosh’ you get when trying to accelerate with a blown hose/ loose clip was not evident but I checked them anyway.

The ebay supplier sent me the connector leads and they arrived this morning, so I will access the fault codes later. Might even be able to decipher them if I can find the manual as well. (Web search will sort that out at ufitech if the later fails)

One last question though, If a knock sensor was dying, loose and or the connector was dodgy would it cause the intermittent hesitation and no faults, then when a bit more serious the ‘1.3 bar max boost then self clearing itself and log odd faults.

Many thanks for all the suggestions as they are all well appreciated. Now going to annoy the Mrs by spending a day ‘in, under and/or around the car’!

I will post the codes later.

Cheers,

Andy H,

[Andyh-R6S]

00540 Knock Sensor 2 G66. (The bad one)

Well, I have two codes and I think the later one is me unplugging the injectors one at a time last night while the engine was running, just to make sure all the injectors were pulsing OK.

00540 Knock Sensor 2 G66. (The bad one)
00513 Engine Speed Sensor G28 Malfunction. ((Probably me and the injectors) could be low RPM as well according to the code book)

I am going to change the Knock sensor but are they easy to do and do they come with the correct connectors, etc? (There looks like a lot of kit to take off and I am wondering due to the age of the car, if it’s simpler to replace both knock sensors while I am in the area?)

But as mentioned previously could this have been causing the slight hesitation I have had in the past but not logging a fault code? Obviously defective now causing the ‘1.3 bar’ boost issue with a fault code.

All though I am around for the next few days I am off abroad again next week, so the job will have to wait until I come home again in mid September.

Regards,

Andy h.

[spink]

worth changing both of them for piece of mind.They should cost approx £35 each from vagparts(S2 ones are).

I have a funny feeling the AAN ones have a longer cable on and/or the connectors colours are different.

this is an ABY one can't remember if its number 1 or 2,the other one has a blue connector(pic nicked off vagparts site)