Noises : ticking

[mukumu kurubushi]

Hi guys, just wanted to ask if anyone else has / had this same noise.

Basically its a fairly noisy fast ticking noise. Doesn\'t happen on idle, but cuts in the further you press the accelerator pedal. When im doing 30 in 3rd gear i can make the noise cut in/out by feathering the pedal. So appears to be something controlled by the throttle sensor at a certain engine speed.

I always just assumed it was the airpump but just wanted to double check

Any help appreciated :god

[m1tch]

Could be a solinoid, I know that depending on what RPM and throttle, different solinoids operate.

[dthebuk]

30 in 3rd is around 2k revs right? probably safe to say its NOT the secondary injectors

[pdtaylor18]

Is this a noise that is solely there on driving or if you rev the engine on a stand still do you also hear it then. If its engine related then you should get this when stood still so maybe if you operate the throttles by hand and then see what area its coming from.

[Prof]

Can you post a video with sound ?

[mukumu kurubushi]

Is this a noise that is solely there on driving or if you rev the engine on a stand still do you also hear it then. If its engine related then you should get this when stood still so maybe if you operate the throttles by hand and then see what area its coming from.

Yep, sorry forgot to mention this, it does this all the time even when stood still. Also gets louder as engine speed increases.

Im not sure if its just me fixating too much on it, but it seems like it gets more noticable once the engine has warmed up... then again maybe its just because im not using my right foot as much when it\'s cold :p

Did think of either a solenoid or relay, but tbh it sounds a bit too loud which makes it difficult to tell where its coming from. I think its somewhere from driver\'s side of the bay which is what made me think of the airpump.

Can you post a video with sound ?

Good idea, i\'ll get this done after work tonight.

Cheers for the suggestions so far :Thumbsup!

[pdtaylor18]

silly as it sounds but an exhaust leak from the manifold/turbo will produce that sort of sound. Mine did that and thought my turbine blades were touching the sides.....another place to look as well.
However mine still makes a similar sound and not sure whether its a combination of bigger ports and exhaust but mine comes from the manifold area. I might still have a leak but diffucult to get at it to check with engine running.

[mukumu kurubushi]

That\'s a good point actually, it could be a gasket.

Thinking about it the boost does drop off a little bit at high rpm, so that might explain that.

[mukumu kurubushi]

Took a sound clip of it this evening. Sorry for the bad quality, it was from my phone and this was the best i could get. I can only describe it as a metallic ticking turning into the loud buzzing you can clearly hear on the video.

It\'s loudest after the first 2 tests on WOT. When i gradually increased the revs it got drowned out by the exhaust and the belts, but the noise is still there and only seems to cut in at full volume above a certain point.

Also when the bonnet was open i did hear a very very faint tick from the manifold area.. but so quiet that i hadn\'t even noticed it before and i was listening for it this time.

here\'s the clip:
http://www.youtube.com/watch?v=nt-pEIlq1cg

[Prof]

That sounds like an exhaust leak - I had a similar noise when the bolts on the back of the down pipe / turbo loosened off and fell off.  Car sounded a little tractor like.
 
Wait until the car cools down - and then check the bolts on the back of the turbo - there are 2 on top and one underneath.
 
If they are all on tight, then the next places to look are the turbo to manifold -  or between manifold and engine block - but these gaskets are metal and don\'t easily break.
 
It might be a crack in the manifold as well.

[mukumu kurubushi]

Thanks Prof, I\'ll have a poke around under my car and check those things. :Thumbs-up

I\'m replacing the downpipe and decatting soon, so if im really lucky that might just fix it!