richard.courcelles

I 'm looking for a bit of help if anyone can give me a yes or no answer that would be great.
I recently changed my upper timing chain tensioners on my 2007 Audi A6. Everything was done according to the video I followed right to testing the timing after completion by turning the engine twice by hand to make sure the timing was still good. The only thing I didn't do that I think I probably should have is disconnect the battery. Is it possible that I could have caused a short in the circuitry which will not allow it to start anymore and if so could it be as simple as a fuse or a relay?
I appreciate any help.
Thanks

aaronfs

Hi there - not sure if you've resolved your non start issue. I had a similar experience when replacing upper tensioners and re-sealing the cam girdles and doing a carbon clean on the intakes. It would turn over fine but seemed to have no fuel or spark. I had an unusual code to do with "low voltage on a 5V circuit". It took ages to track down - I thought I'd fried the ecu...
Turns out it was a piece of swarf which was stuck in one the intake flap sensor plug; bridging the 5V supply and ground prongs. This was "shorting" the 5V engine control circuit.
I diagnosed this by systematically unplugging all the sensors (cam position, vvt actuators, flap position sensors, etc) one by one and checking for codes until the "low voltage" code disappeared. Once I found the offending sensor, I plugged all the others back in and the engine started perfectly.
I thought I had a faulty intake flap position sensor, however upon inspection found the offending strand of wire (it had come off one of the wire brushes I had used to clean carbon off the intake!)
Hope this helps!