Gear box or Engine?

th3k1d · Postby **th3k1d** » Tue Feb 26, 2013 9:13 pm

Hi guys... sooo... my NA6 has started to make a tapping sound when under load at 2500 to 3000 rpm... only thru that rev range does it make the sound and it is loudes when in 3rd... now i know my gearbox is not the best... it rattles when decelerating but it still shifts fine... so i feel i should ask here what ppl may think it is... is it just my gearbox saying "change me soon" or is it something more sinister :evil:

bruce · Postby **bruce** » Tue Feb 26, 2013 9:16 pm

Is there oil in your engine?
I am serious.

th3k1d · Postby **th3k1d** » Tue Feb 26, 2013 9:17 pm

haha yeah man im not that stupid... i did a service not that long ago and i also check it once a week.... the gearbox oil was also changed about 3 weeks ago

de Bounce · Postby **de Bounce** » Wed Feb 27, 2013 5:42 am

A specific noise at a specific rev range generally points to something vibrating that shouldn't.
Have a look for a broken exhaust shield

Good luck

manga_blue · Postby **manga_blue** » Wed Feb 27, 2013 9:03 am

It's not ignition pinging , is it? Sounds like a man with a tiny hammer is tapping on the top of the motor. Mostly heard under load from around 1500 to 3000rpm. What's your timing advance set at and what grade of fuel are you using?

Magpie · Postby **Magpie** » Wed Feb 27, 2013 10:31 am

de Bounce wrote:A specific noise at a specific rev range generally points to something vibrating that shouldn't. Have a look for a broken exhaust shield.

This was the problem with mine and I thought it was the gearbox, turned out to be the heat sheild!

KevGoat · Postby **KevGoat** » Wed Feb 27, 2013 10:48 am

th3k1d wrote:... now i know my gearbox is not the best... it rattles when decelerating but it still shifts fine...

Just regarding the sound from the gearbox (I know you are asking re the engine noise) ... have a look at the clutch fork. Spring comes loose and it resonates through the car like a faulty exhaust baffle ...

de bounce wrote: A specific noise at a specific rev range generally points to something vibrating that shouldn't. Have a look for a broken exhaust shield.

Also all the pebbles that collect between the shields/body! Filled top of a plant pot nicely with all the rocks that fell out from mine :lol:

fcruz3r · Postby **fcruz3r** » Wed Feb 27, 2013 3:08 pm

not an expert, but sounds like it may be pinging due to too advance timing or poor fuel. May still be present at higher revs but since it happens quicker ..it's less audible (if that makes sense). Also possible that at higher revs or WOT the fuel trims from factory may be set to run rich ...hence less ping?? Again not an expert in these cars having just bought my first one about 2 weeks ago and still going through a maintenance (and lighter wallet) phase.

but check for loose bolts on exhaust manifolds and exhaust shields first

th3k1d · Postby **th3k1d** » Wed Feb 27, 2013 4:20 pm

thanks for the replys... i have a feeling it may be the timing... i will take a look at it and see... i dont have a heat shield so it cant be that lol

hks_kansei · Postby **hks_kansei** » Wed Feb 27, 2013 4:50 pm

th3k1d wrote:i dont have a heat shield so it cant be that lol

There's multiple.

One over the headers near the engine
Another down near the collector (2 piece one that often rattles as the spot welds rust away)
Then there's one above the cat I think
one covering the cat
another above the rear muffler.

The second one in that list is usually the one that rattles, it's a 2 piece one that's just spotwelded together, over time the spotwelds rust and the shield becomes loose.
It then rattles and makes a sh*t sound. (usually it's more a buzzing/grinding noise than a tapping, but look at it anyway)