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Audi V8 4,2 aut -92 running att even speed at above 90kmh makes a very short interruption and somtimes it feels as an smal acceleration ,just after, just like when lock-up goes in. It all takes perhaps one second and nothing shows on instuments and can hapen aprox. once to ten times for 10km ride,
It´s not the waveformed run as when lambda is out of order and it´s not AC compressor engaging
Dont know if it is lockup that goes out and in or engine that stops and starts
Lockup works as normaly . Goes in at 90 and out in perhaps 50-80 depending on footwork. All other gearchanges are so soft that I can´t feel them.
Engine also runs great 1,2 to 1,3 liters / 10km
No faultcodes at engine but at autotrans there is "no brake switch signal " error . This error is there even if I press brake pedal. This error has been there before this problem started.
I read somwhere that brake signal is used to get lock-up out when brake is pressed and ABS i indikating that some wheel not is rotating. This could bee what happens but how to verify this and fault finding ?

Bengt

Hej Bengt,

the Brake-Light-Fault is normal - simply ignore it!
Probably you have a leck in the intake are depression system. This is a quite usual fault which has less effects if the engine is not turbo charged but may cause problems like you've described. Check the hoses for the depression system for leaks.

Hej da

Bastian

Hi !

You had the right answer Bastian !
I have had my V8 in garage now for half a year doing cambelt change and some other tings. Also found the vaccum leak in the hose between the camshaft covers and now the strange feeling of small interupt of power is gone.
Made an "new" hose of the existing moulded hose ends vulcanized to an new straight hose. Lets see how long this hose live.
Can also tell you all that it´s no problem changing cambelt without the special tools holding the camshafts , as long you mark the wheels positions and not loosen the belt wheels on camshafts. You need an tool to hold the multibeltwheel on crankshaft ( can bee homemade ) when loosening/fastening the big screew and it can bee good to have an tool ( can also bee homemade ) to bee able to rotate the camshafts by grabbing the holes in its weels when putting the new belt on.

Bengt

Hej Bengt,

at förs: Bur du i närheten af Malmö? Jag har tittard en Audi V8 bilen i augusti pa en motorvägstationen mellan Halmstad och Malmö (Aug. 17). Jag har varit i Skane pa semester och fotograferad den ochsa. Jag kan sända det foto med elektronisk posten när du är nyfiken

Well, can't continue in Swedish (yet): Nice to hear that I was right, I'm impressed. Be really careful with the cambelt as there have been dozens of engine problems which derived from camshafts calibrated in the wrong way. The idea of the special tools are that you can loose the connection between toothwheel driven by the cambelt and the camshaft itself to perfectly fit the timing of the belt. Most often you don't head into troubles if you just mark the positions, but it CAN end in a horror trip of error searching or even worse!

And don't tell me anything about self-made tools for the crankshaft bolt... such a crazy idea was the reason why I had a serious car breakdown two years ago on my way back from Sweden. An expensive trip I can tell you...

Hej so länga

Bastian

Hi !

Impressed of your swedish , mutch better than my german!
What is your connection to Sweden as you take time to learn it at travel here ?

It seems we have a lot of old audi V8 imported from Germany in Sweden and they are not high priced. You got a lot of car for the money but can also get a lot of trouble.

Regarding the timebelt , I don´t think it is risky to change it my way as long as you mark it up an is sure the marking is the same afterwards ( If you know what you are doing ) The belts are so exactly in the tooth pitch so it could not go wrong by that reason .

I will add a picture´s at the tools

Bengt

Hi Bengt,

well, there is no special connection to Sweden like relationships, my girlfriend and me simply greatly enjoy your country! Therefor we decided (or better to say: it was my girlfriend's idea) to join a swedish course in Vienna for more than one and a half year now, and slowely but constantly we get a little bit into it.

At the moment I'm in Denmark (Aalborg) for post-graduate studies for some months, so I at least get more into the written word, unfortunately the way of speaking here is totally different to the one I'm used to from Sweden. Nevertheless, I also enjoy the Danish culture and people and feel very comfortable here.

Have you noticed the Audi V8 Classic Line which has been sold in Stockholm two months ago? More interesting for you than for us, due to distance and import considerations.

Do you want to tell aus more about your V8?

Well, about the timebelt: I myself never had any problems with just using a marker and exchange the belt. BUT we had some reports from cars with lots of troubles due to that practice. I can't tell if people are just fumbler who exchanged the belt in that way and simply didn't take care or if is a more serious problem. If you say the timing belt didn't length for even en millimetre (as that's usually the problem..) , it should make no difference at all, you're right.

Your tool looks pretty in comparison to what we did - I guess it's really okay. We countered the central bolt at the flywheel and accidently broke a diagnostic pin from the flywheel, which later on (5000km later on...) cut off the ignition point sensor indication pin from the wheel. Result: Engine off in the middle of the night. Flywheel broken. Hurray

Best regards

Bastian

Hi again !

My lady thinks we have cars and bikes enough so I try to avoid sales advertisments ( but its real hard ) . I don´t realy know witch of the wehicles I could sell , want to keep them all.

My V8 came from Germany in late ninety and I bougt it for about five years ago. Now it has gone 29000km and still almost feels and looks like an much newer car. It´s an black/dark blue metalic 92 4,2 auto with what I think most of options .

Bengt