4AGZE Gurus Pls Help : Engine developed knocking sound

[feral4mr2]

you could also remove a spark plug lead at a time (and then replace) while the engine is producing the noise (high rev over the 1500rpm you mention) to see if the noise is generated from a specific cylinder.
eg. if noise goes away or quietens when a lead is pulled off then the problem is in that cylinder.

[mic*]

you could also remove a spark plug lead at a time (and then replace) while the engine is producing the noise (high rev over the 1500rpm you mention) to see if the noise is generated from a specific cylinder.
eg. if noise goes away or quietens when a lead is pulled off then the problem is in that cylinder.

How does no combustion in a cylinder prevent noises from a worn spring / bucket / valve ?

[1200det]

How does no combustion in a cylinder prevent noises from a worn spring / bucket / valve ?

No combustion means no explosion and no downward force on the piston , So without spark that certain piston will be just moving up and down due to being connection to the piston and not from the combustion



.

[mic*]

No combustion means no explosion and no downward force on the piston , So without spark that certain piston will be just moving up and down due to being connection to the piston and not from the combustion



.

Yeah... so. Read my question again mate. Valvetrain noise Im talking about. Which is the only cylinder specific problem mentioned above.

Valves come down because of cam lobes & lifters. Valves go up because of springs. If there is noise in the mechanical operation of thereof, how will the abscence of combustion really affect this?

[1200det]

Yeah... so. Read my question again mate. Valvetrain noise Im talking about. Which is the only cylinder specific problem mentioned above.

Valves come down because of cam lobes & lifters. Valves go up because of springs. If there is noise in the mechanical operation of thereof, how will the abscence of combustion really affect this?

Sorry i thought you were talking about Big or little end bearing issues , In which what i explained would make this diagnosis straight forward.

[Ghetto-Spec .:bayka:.]

Ok Thanks everyone.

So it may still be a bearing even if the RAC guy proved the noise wasn't coming from low in the block? He was pretty sure it was originating from the head but couldn't pin point.

What is a big end bearing? Im assuming a crank bearing or something majorly gay like that? what exactly is involved to change it, or is it basically get a new engine ?

I will definately dump the oil (as its brand new FUCHS synthetic) so if shavings are there i'll friggin see them

slide86: thanks for that i will definately check each one for damaged lifter etc.
wiso: cheers i will take of sc/water pump belt and run it for a minute to see if the noise is related.

**FUUUUUUUUUUCK**
The engine has about 80000kms on it, always warmed up and cooled down...and has been running hard for over 9 months without a hitch.

[feral4mr2]

How does no combustion in a cylinder prevent noises from a worn spring / bucket / valve ?

well it might not do bugger all for worn spring/bucket/valve.. which i did not mention in my post. it does however give good indication of what cylinder/s may have a stuffed conrod bearing (big end bearing) or piston problem (yes damaged pistons knock too, personal experience).

dont be fooled by the noise appears to only come from the top/head of the engine, it's funny how a bearing noise can protude up there.

[EVOSTi]

exactly, dont trust where you think you hear a noise coming from, and also dont trust RAC, or in NSW NRMA which is widely accpeted as meaning No Real Mechanics Available

im curious as to how they PROVED the noise wasnt coming from the bottom end?

i know you dont want to hear it, and i could be wrong but from my experience with 4A's and engines in general, what your describing is a big end bearing. it wont necesarily show up in oil either so dont simply drain the oil and come to the conclusion its not a big end. remove the sump, then remove the the big end bearing caps and check the bearings visually. if you want any pointers PM me and ill help you out where i can. im a mechanic, ive done various 4A's and have a workshop manual for the GZE, and not all GZE's have the same torque for thier big end caps.

[fixeruperer]

could be an gudgen pin bush if not a big end, big end sounds a bit harsher.
and yes dont trust rac they are stupid i meen stupid.

[Ghetto-Spec .:bayka:.]

well.... "PROVED it wasn't bottom end" was a little optimistic embellishment on my part ok, he basically noticed heaps more noise from the head and bellhousing which was a little odd. He also held the stethoscope along the side of the block and at the bottom and didn't think it was bottom end / gudgeon pin.

Im going to rip off the sump now, wheres all your optimistic support for bullet-proof 4AGZE's guys??!!

I'll host some video footage of the anomoly ASAP aswell.

Peace Out

[fixeruperer]

you havent proved anything till the broken part is in your hands.
iwas thinking that too about 4agz optimism i never herd of so many fuked 4ag than in this thread im putting it down to you ppl are doing something rong

[myne]

pulling plugs from a cylinder can also quieten bigend noise.

I spun a bearing in an old civic I had. Because I needed it for another 2 weeks, I pulled the plug on #3 and kept driving. 2nd gearies on 3 cylinders ftw!

[Ghetto-Spec .:bayka:.]

-- video footage up --
http://members.westnet.com.au/bomrekab/4agze.mp4
1MB, will run on VLC player or any decent media player

-- sump off : the verdict --
Didn't notice anything when we dumped the oil as some of you predicted, however when we got the sump off there are quite a few (around 15-30) little oblong roundy shards of metal ranging from around 2-3mm in diameter. IS IT ALL OVER?

It looks like there are 5 bearings along the crank, so a big end would be one of the end ones? I'd assume flywheel end? Do you just remove the 2 bolts at the bottom of the bearing to visually inspect??

[wiso]

there should be 9 bearings on the crank, the big end ones are on the conrod (4 that attach to the pistons) and then you have 5 main bearings in between each of these big ends

[go_the_datt]

slightly off topic but how much roughly to replace all these bearings. genuine and non.
sorry if this'll dis-hearten the authur. lol
cheers