Jake Posted June 12, 2006 Share Posted June 12, 2006 I've just started using my 98 VVTi Tiptronic again, so I can run-in the rebuilt engine. When I first pull away from a standstill there is a knocking noise. It sounds like the propshaft. It only does it when pulling away and doesn't matter if I'm turning left or right or going straight ahead. Only seems to do it up to about 5mph. It didn't knock before I took it off a few months ago. It's been laid outside under the car all that time. Is the propshaft the most likely suspect? Anything else it could be? Could it have seized up? Are they serviceable or will I just have to replace it? Thanks Quote Link to comment Share on other sites More sharing options...
JohnK Posted June 12, 2006 Share Posted June 12, 2006 If you do have to replace it, I will have a UK auto prop available soon, Im unsure it will fit a VVTI though, you would need to check. Quote Link to comment Share on other sites More sharing options...
Bob Posted June 12, 2006 Share Posted June 12, 2006 Carbon replacement, maybe? Quote Link to comment Share on other sites More sharing options...
Jake Posted June 12, 2006 Author Share Posted June 12, 2006 Is the propshaft the most likely suspect? Anything else it could be? Could it have seized up? Are they serviceable or will I just have to replace it? Anyone ? Quote Link to comment Share on other sites More sharing options...
Alex Posted June 12, 2006 Share Posted June 12, 2006 As you know noises are hard to diagnose. Do you have access to any chassis ears? (earphones for listening for knock)..if you did you could try attaching them to points close to your suspect and nail it down that way...or jack the rear up and get someone to put it in gear??? Quote Link to comment Share on other sites More sharing options...
Gordon F Posted June 12, 2006 Share Posted June 12, 2006 Is the propshaft the most likely suspect? Anything else it could be? Engine /gearbox mounts maybe Quote Link to comment Share on other sites More sharing options...
Jake Posted June 12, 2006 Author Share Posted June 12, 2006 I was thinking about it and can't see how the prop shaft would have seized up really. I'm wondering if it could be the torque converter. ....but then maybe not, because it only makes the knocking noise when you start moving. If I hold the brakes and press the throttle, with the shifter in 'Drive', the car strains trying to go but doesn't make the noise - that would rule out the TC being the problem, wouldn't it? Quote Link to comment Share on other sites More sharing options...
Miguel Posted June 12, 2006 Share Posted June 12, 2006 Does its do it in neutral sitting on the drive ? If so it could be anything from the TC forward. If it does it only while the drivetrain is active then that moves the problem to that area. I would go round check gearbox mounts , engine mounts propshaft doughnut ect ect and make sure everything is as it should be. Quote Link to comment Share on other sites More sharing options...
Jake Posted June 12, 2006 Author Share Posted June 12, 2006 Yeah only when moving, and only from 0 to 5 mph. Very odd. I'll check it over tomorrow and if I can't find anything up I'll swap the propshaft from the grey car onto it and see what happens. Quote Link to comment Share on other sites More sharing options...
Alex Posted June 12, 2006 Share Posted June 12, 2006 Does it happen in reverse? Quote Link to comment Share on other sites More sharing options...
Jake Posted June 12, 2006 Author Share Posted June 12, 2006 Nope, doesn't seem to Quote Link to comment Share on other sites More sharing options...
Alex Posted June 13, 2006 Share Posted June 13, 2006 Doesn't that then suggest that it's not the prop? Doesn't it suggest a mount issue? Quote Link to comment Share on other sites More sharing options...
Jake Posted June 13, 2006 Author Share Posted June 13, 2006 I was thinking that because the propshaft is spinning in the other direction when in reverse that the stresses on the joints would be in different places so maybe wouldn't knock. Quote Link to comment Share on other sites More sharing options...
Jake Posted June 13, 2006 Author Share Posted June 13, 2006 ***Update*** The propshaft seems fine. I think it's either the gearbox or the torque converter that is making the noise. Laying under the car the noise seems to be coming from that area. My money is on the box because when the engine blew up the car was in a dangerous place on the motorway and had to be towed about half a mile to a safer place, and was then put on a low-loader (when it finally arrived) Would that be enough to ruin an auto gearbox? The fluid in it looks like new. Does anyone know if the gearbox on a Tiptronic is the same as a pre-vvti TT auto box? I'm having a nightmare with this car! Quote Link to comment Share on other sites More sharing options...
Miguel Posted June 13, 2006 Share Posted June 13, 2006 Does it sound more like front end of the Box ..I just remembered the spate you had with the TC when you dropped it/ put it it wrong. Think it may be something do to ??? Quote Link to comment Share on other sites More sharing options...
Jake Posted June 13, 2006 Author Share Posted June 13, 2006 Hard to say exactly where the noise is coming from. The TC was working fine up until the engine blew up. It hadn't done a lot of miles since the rebuild where it got dropped (by my father-in-law ) but it was working fine. Quote Link to comment Share on other sites More sharing options...
Miguel Posted June 13, 2006 Share Posted June 13, 2006 Opps my bad Jake ..sorry about that. I forgot this is the the 2nd time round...Smacks self on head. Quote Link to comment Share on other sites More sharing options...
Jake Posted July 12, 2006 Author Share Posted July 12, 2006 ** Update ** Finally got round to sorting this out. Replaced the propshaft and it's fine now. No knocking at all. Quote Link to comment Share on other sites More sharing options...
Miguel Posted July 12, 2006 Share Posted July 12, 2006 Well done Quote Link to comment Share on other sites More sharing options...
LeeT Posted July 12, 2006 Share Posted July 12, 2006 ** Update ** Finally got round to sorting this out. Replaced the propshaft and it's fine now. No knocking at all. so what was wrong with the prop? did you split the two halves when you took it out and not align them back up PROPerly? Quote Link to comment Share on other sites More sharing options...
Jake Posted July 12, 2006 Author Share Posted July 12, 2006 No, I didn't split the two halves. I wasn't even aware that they came apart. Do you have to undo a circlip or something to get apart? I've never really looked. Quote Link to comment Share on other sites More sharing options...
LeeT Posted July 12, 2006 Share Posted July 12, 2006 No, I didn't split the two halves. I wasn't even aware that they came apart. Do you have to undo a circlip or something to get apart? I've never really looked. No, you just loosen that big locking nut in the middle then pull them apart. I take it you didnt remove it by loosening this nut then pushing the two halves together then? It makes removing it a lot easier Quote Link to comment Share on other sites More sharing options...
Jake Posted July 12, 2006 Author Share Posted July 12, 2006 No, I've always taken them off in one piece. It's a bit of a struggle getting them back on. I'll remember that for next time though! Quote Link to comment Share on other sites More sharing options...
LeeT Posted July 12, 2006 Share Posted July 12, 2006 No, I've always taken them off in one piece. It's a bit of a struggle getting them back on. I'll remember that for next time though! It will still come off in one piece, you loosen the lock nut then push the two halves together,effectively making the whole prop shaft shorter. Makes life a whole lot easier Quote Link to comment Share on other sites More sharing options...
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