metal scraping type noise from engine bay at 3500 to 4000rpm

[jamesharley]

hi guys im a bit of a newbie when it comes to engines and mx3s i got mine about 6 months ago its a decent car 600 off ebay! but ive spent a load already on a new alternater new factory backbox pads and disks and oil change ive got it up to scratch now. ill get to the point !! when i get to about 3500rpm there is a unbearable scraping noise coming from the engine bay? this happens in every gear and when its in neutral i think its something to do with the throttle body plate vibrating im really puzzled any clues ? next month im going to replace the EGR valve and the 02 sensor the only mod on it atm is a k&n which i think has made no diffrence after 10mins it gets warm!! if anyone could help me with the irritating noise that would be great

[Ryan]

My #1 advice is quit replacing parts without diagnosing them. You're throwing your money away.


Play with the throttle in the engine bay and listen for the noise, and see where its coming from. It could literally be thousands of things, many of which none of us could imagine.

You also have to tell us the year and model.

[jamesharley]

ok cheers i wont buy nothing i just want to get the best out of it! its an R reg 1.6 DOHC manual 103,000 on the clock ive played around with it all day!! the noise is coming from the tb or very near that area but only at 3500rpm? to about 3800rpm? ive checked all round the engine bay im almost certain its coming from the tb ive oiled the t cable and spring fiddled with all the pipes and hoses i even put the factory air box back on the noise is like someone putting an angle grinder on some tin? if that helps i went to a garage the guy wanted 80quid befor i popped the bonnet!

[Ryan]

yeah, garages are overrated.

Would it be easy for you to take a video of it? I've never heard of a noise like that from the throttle body. Not many moving parts in there, for sure none that move quickly that would make a grinding noise.

[jamesharley]

yeah spose your right mate its like 3:25am s ill put a vid on in a few hours so you can have a listen its really bugging me now!

i noticed the noise after i red lined it for like 3 secs on the motorway by mistake there was a pug gti up my a--! i had to let him go 107 is pityfull top end! i also notice when i pull off in 1st sometimes theres a slight delay if that helps?

[Mi|<E]

Loose heat shield ?

[jamesharley]

yep!!