Robbo149 0 Posted March 31, 2004 Can you knowledgeable chaps tell me what the possible causes for my popping exhaust could be? If I rev it at idle I get some quite loud popping on the overrun (only when the engine's warmed up). I've read a few threads which mention the Lamda probe, would this show up on VAG-COM ? as I've recently had it checked & no fault codes were found. I've also heard mention a possible bent valve! :pale: I've also noticed that the tailpipe gets quite sooty. A visual inspection of the exhaust would indicate that it's not in brilliant nick!, the middle box seems to be twisted out of alignment, could this be a possible cause? Should I be overly worried? Thanks, Robbo Quote Share this post Link to post Share on other sites
phaserno1 0 Posted March 31, 2004 I am having the same problem at the moment, my exhaust gets sooty within two or three drive to work... i thought it was my valves but they have all been replases two monts ago so i can rule that out. it dosent smot at all and all the tests done come out positive....???.... I think your middle box wouldent cause this to happen. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted March 31, 2004 Soot usually means running rich, doesn't it? Do you do a lot of short journeys? Quote Share this post Link to post Share on other sites
Robbo149 0 Posted March 31, 2004 dr mat - yeah, all my driving is short journeys as I only live a couple of miles from work, could this be a factor? Robbo Quote Share this post Link to post Share on other sites
Guest Posted March 31, 2004 take it out for a longer drive at the weekend, that'll help your battery too :) Quote Share this post Link to post Share on other sites
dr_mat 0 Posted March 31, 2004 Yup, these things run phenomenally rich for two-three minutes on cold starts. 6MPG is not unusual!! It's only once it's up to temp that you can tell. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted March 31, 2004 Might have a slight weep on one or two of the injectors. When the Throttle position sensor sees 14 degrees, it goes into overrun/idle and closes the injectors. Or maybe the injectors are just getting old and slow to react, a bit like me :lol: I've not heard many VR6s *not* pop on overrun. So long as it's quiet and not exhaust box shattering, don't worry about it. You just have to accept the fact that the 2.9 engine is not smoothest or longest lasting of the VR engines...... K Quote Share this post Link to post Share on other sites
Guest Posted March 31, 2004 mine pops a bit on over run, but nothing I would describe as loud, its the nature of the beast Quote Share this post Link to post Share on other sites
Robbo149 0 Posted March 31, 2004 I do try to get out for a good thrash at the weekends (ooeer!!!). Did about 300 miles last Sunday & it was still popping all the while. It's not loud like a backfire, it's more of a burble really. I guess I worry too much, but I tend to be a bit of a perfectionist when it comes to cars, as I'm sure you guys are. Why put up with your car only been 99% healthy, when spending another grand will make it perfect?!!! (as if!) Cheers, Robbo Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted March 31, 2004 Yeah a burbling is normal! You should hear my mate's Scoob! Sounds like there's a pneumatic drill in the rear box! Quote Share this post Link to post Share on other sites
phaserno1 0 Posted April 1, 2004 Thanks guys...i shal put it do to the beast under the bonet...... glad i found this forum wicked keep up the good work.... :D Quote Share this post Link to post Share on other sites
Robbo149 0 Posted April 1, 2004 Popping update - been monitoring a bit more closely since yesterday & I'm rethinking the 'burble', it is definitely more of a popping. It's fine when cold - no popping at all, it only does it when the engine's fully warmed up & also only does it with a slight blip of the throttle, if I rev it up to like 3k & then back off it doesn't seem to do it. Any more ideas? Just worrying a bit cos I don't want to knack the cat (unless it's already Knacked of course!!!). Cheers, Robbo Quote Share this post Link to post Share on other sites
Jonathan 0 Posted April 1, 2004 Mine has done this since I bought it 4 years and 40k miles ago. The cat is still fine and I don't wory about it any more. VAG-com shows nothing other than an occasional '00537 -lambda regulation 11-10 control limit not reached (or exceeded) interittent)'. I have put it down to a slightly leaky injector and don't worry. Jonathan Quote Share this post Link to post Share on other sites
