Sharp rap

[Proman]

whats causes the sharp rapping/scrapping sort of noise when ya accelerate abit harder than normal??? is it the lifters?

[Brett_jjj]

Does the noise occur when the car is not in gear and the engine is revved?,If so,It could also be one of the idler pulley bearings or AC compressor, alternator,or water pump bearings.These bearings,when worn,can cause all sorts of funny noises that can sometimes sound like they are coming from inside the engine.Id start by removing the serpentine belt and then start the engine and rev it and see if the noise goes away.You can safely run the engine for a minute or two with no belt.

[Proman]

yeah it does it when im in park as well and give it a good rev, ill have to check all that cheers brett

[hako]

Sounds more like a big end bearing gone to me or a split/cracked exhaust manifold or down pipe.

[Proman]

wouldn't a big end bearing make a heavy dull knock, it sounds more a like chatter noise at high revs

[hako]

Depends on how bad it is worn, however have a look at this site for some good explanations of engine noises. 4. Engine Noise Diagnosis 101

[Proman]

Ticky tappy knocky clacky clicky nicky rap tap
Aha love it, cheers again hako

[Proman]

i remember posting on here about a month or so ago when i first got the car, the oil was black and dirty as sh!t when i first got it, and was making a similar sound, i assumed it was the lifters, so i changed the oil and the noise went away, do you think it might just need a second oil change, the colour of the new oil i put in about a month ago isnt to bad now, i mean it dont look like new oil but still looks pretty good, maybe a flush is due perhaps??

[nathanVY]

As brett_jjj said, check your pulleys. I had the same thing, all my idler pulley bearings were shot.
Easy fixed, $30 each changed over in 10 minutes.

[moff_man]

if its been grandmotherd around and than given a thrashing it could be pinging.

[hako]

An oil change certainly won't harm anything - I'd go for the thickest multigrade oil - 40/70 I think.....that should quieten the lifters if that's the problem. From your description of the noise -
Ticky tappy knocky clacky clicky nicky rap tap it sound like lifters plus seeing as it went away before after changing the oil I'd do it again.

[Proman]

do them 300ml bottles of lifter free work?

[hako]

Couldn't do any harm I suppose - it really depends on why they are tapping - if it's a bit of crap blocking the valve in the lifter then 'lifter free' may possibly flush it away, however if it's worn lifters which are leaking and cannot hold pressure then thicker oil will help them hold pressure. I've heard of people adding a litre of ATF to clean them out (then do an oil change).
If it was me, I'd add a can of engine flush, then change oil and filter using a heavy oil and see if it goes away. If it returns I'd try to locate exactly which lifter is noisy and replace it (they're not expensive). Lifter noise can get worse but it usually will not kill and engine.

[Proman]

Code 76 is coming on now, something to do with fuel/air ratio left or right right bank, in gregorys manual it sais one of the problems could be exhuast leak, do you think this high pitch rap noise could be related?? the weird thing is the engine light pops on when starting the car for the first time, so i turn the car off then restart the car then the code never appears while driving?? and im pretty sure its not the 02 sensors

[Proman]

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