On an FD, that is.
Picked up my FD from RoTechniks last night and on the way back it started developing a buzzing noise which was related to engine revs only - not load or car speed. Originally it sounded like a heatshield or similar was lose and buzzing at certain revs. As soon as the revs dropped a bit lower, the noise was gone.
By the time I got home, it was doing it in the whole of the restricted rev range I\'ve got to play with (idle to 3k) - at idle it goes "tick, tick, tick" and as the revs increase its turning into the "buzzing". My first thought when I finally got home at stupid o\'clock was that it\'s something like an alternator bearing but some poking around under the bonnet in the dark suggests that it\'s not coming from the front of the engine. The noise seems to be originating from underneath the inlet manifold, roughly below the intakes for the front rotor and definitely closer to the driver\'s side/turbos. Not quite sure what\'s underneath there though - it\'s "only" the rat\'s nest, right?
I can\'t tell if the car is boosting as the boost is turned right down and I\'m driving it like I\'ve got a couple of crates full of raw eggs in the back as the engine probably has about 100-150 miles on it now. It was idleing fine, don\'t know about starting as I don\'t want to fire it up just for a few minutes without driving it.
Any ideas as to what this is? Obviously I\'d call RoTechniks this morning with the news but some suggestions as to what it is and how serious it is in units of RAC recovery vehicles :) could be helpful...
Sounds like an turbo manifold leak?
Sounds like an injector. If it\'s doing it at idle it\'ll be one of the primaries.
there are blanking planks in that area (single turbo), may have come loss, had same thing
Well, my FD\'s a twin turbo so I\'m not sure where if you\'d still find some blanking plates there. Injector sounds possible but that would be a tad worrying when it comes to driving the car back.
Time for a phone call now, methinks.
Could be a noisy solenoid ?
Maybe it\'s got the optional solenoid-controlled ignition :D.
Top marks to RoTechniks, they immediately offered to organise the transport of the car back to their premises in order to have a look/fix the problem :god.
Yep - customer service is definitely on the \'up\' there ! :Thumbsup!
They are also easy to work with, which is important for the \'tinkerer\' like me. I just let them know which bits I want to do - they are even willing to offer advice.
Well, the word is that it looks a bit like a Heisenbug (http://www.wordspy.com/words/heisenbug.asp) as it doesn\'t do it straight away. That said, there is a potential exhaust gas leak on the second turbo that may well show up when enough heat has leaked into the turbo (running in the car obviously means that I wouldn\'t rev it high enough to bother the second turbo.
They\'re investigating it over the next couple of weeks so hopefully we\'ll be getting somewhere by the time I\'m back from the US of A.
hmm... mine has a similar ticking noise too... but only when on boost... doesn\'t seem to affect the level of boost either, so i just assumed it was ok...
will try an get a video of it soon.
Well, I\'ve got the car back now - they did find that the belt tensioner pulley had a duff bearing, plus there was a leak in the actuation mechanism for the flap that redirects exhaust gasses to the second turbo.
Let\'s see how this\'ll pan out.