View Single Post
  #90  
Old 31st October 2020, 09:54 PM
ainarssems ainarssems is offline
Senior Member
 
Join Date: Aug 2010
Location: Rushden, Northants
Posts: 3,854
Default

Quote:
Originally Posted by MikkiJayne View Post
Yeah thats feasible

A frustrating day today. I got the front panel back on and filled all the fluids. Still no brake hoses so I can't finish the brakes and so can't check the gearbox properly, but the engine starts up with no leaks



However... the replacement fan bearing failed immediately on startup and became loose and rattly I had to pull the fan, belt etc and replaced it with a good OE one which is all I had available. I will investigate getting a proper FAG or SKF bearing to replace the no-brand one the part comes with, and just use the housing.



After this was all back together the engine was nice and quiet but I noticed the TCU would go in to limp on every startup with a low voltage code When the code is cleared it's then quite happy, but at every power-up it gets the error so starts in limp every time. Swapping the TCU solved it, which is extra frustrating as I sold my spare S8 PRNDS TCU to Scott the other day to fix his tiptronic problem I do have a PRND432 TCU spare though so that'll go in for now while I seek a proper replacement.

Finally, I pulled out the jumper I had put in the starter interlock relay before it went on the lift, confident that the replacement wiring harness would solve the lack of a neutral signal from the F125, but it was not to be Still no start with the relay back in, so the F125 needs to come apart for inspection. At least that doesn't take long on an S8, especially one that's just been apart.

No leaks though...
2 things,
1) could it be aged capacitors in TCU that resulting in low voltage error and be replaced and
2) can it be updated from PRND432 to PRNDS with a software update.
__________________
Currently 8less
2011 Q7 S Line 3.0TDI, 2016 Tesla Model S 90D

8 history:
2006 A8 Sport 4.2TDI quattro SOLD,
1997 S8, reached end of life with gearbox failure
Reply With Quote