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Rattle In Engine - 'spun A Bearing'? What The?

dan.1337

By dan.1337,
in Engines & Forced Induction

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SECURITY Grand Master

SECURITY

Posted
Posted
this noise you've mentioned, is it meant to be loud and obvious or quite quiet??

also, when a bearing is spun, does the car start to lose compression and hunt on idle like when the AAC valve is blocked?

you can get a stethoscope and put it to your block then put it to the head and see where its louder.

alternatively, get under the car and get someone to hit the accelerator and see if you can hear it more under the car, or from the top. bottom = bearings, head = lifters.

worn lifters will make almost the same kind of rattle but isnt something that will need attending to for a while.

bearings are pretty loud/noticeable, lifters are quieter. both increase as you rev.

bubba Grand Master

bubba

Posted
Posted

Use a long flathead screwdriver touching various parts of the engine and holding your ear to it, should help you narrow down where the noise is coming from (basically a backyard stethescope :))

dan.1337 Proficient

dan.1337

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Posted (edited)

whoa that is pretty loud. if i'm not mistaken, ur referring to the thing that sounds like someone is tapping their fingers on a piece of sheet metal in some sort of tune?

edit:

i just went out to have a listen. it sounds like a fast consistent ticking sound (not very loud, my phone couldn't capture the sound) and it doesn't really sound like it's coming from the rear bottom of the engine either. it sounds like it's coming more from this part of the engine:

4ms0i9g.jpg

when i rev it up and take my foot off the accel, the ticking stops and restarts on idle.

Edited by dan.1337
SOOKIE Enthusiast

SOOKIE

Posted
Posted

RB20s are usually not too bad with bearings, SR20s are the true bottom end bearing destroyers. I've destoyed a couple of them. I had a mate who thrashed his R32 for years (drove it like it was stolen, literally) and never had a problem, then swapped it for a clean SR20 silvia and blew the engine within a month because he revved it like an RB20. Not many engines can rev as well as an RB20!

Best thing to do is rip off the sump pan yourself, put a magnet in there and see if any shavings come out, if they do, the engine is finished because the crank is scored (bottom end bearings aren't metal). Then put the sump back on and fill with cheap crap oil and thrash it until it blows (fun). Then source a clean stock replacement, all up shouldn't cost more than $1800 including labor. If you don't get any metal shavings in the sump, then you can decide on whether you want to pay big bucks and replace the bearings etc. or change the oil and hope for the best.

My friend had a knocking noise coming from his RB25, which we thought was the bottom end bearings but he changed the oil a couple times and its gone away and hasn't had a problem since.

The point I make is: change your oil and oil filter regularly and you shouldn't have a problem. I have not yet blown an RB20 and I drive them very hard so don't blame the engine, blame the poor servicing history.

r32woohoo Rising Star

r32woohoo

Posted
Posted

If i didnt know better id say there was a very musical creature living in your engine playing drums :)

r32woohoo Rising Star

r32woohoo

Posted
Posted (edited)
whoa that is pretty loud. if i'm not mistaken, ur referring to the thing that sounds like someone is tapping their fingers on a piece of sheet metal in some sort of tune?

edit:

i just went out to have a listen. it sounds like a fast consistent ticking sound (not very loud, my phone couldn't capture the sound) and it doesn't really sound like it's coming from the rear bottom of the engine either. it sounds like it's coming more from this part of the engine:

4ms0i9g.jpg

when i rev it up and take my foot off the accel, the ticking stops and restarts on idle.

That would be the injectors squirting away

My ones used to do it

and then i put GTR ones in and it got even louder

Edited by r32woohoo
dan.1337 Proficient

dan.1337

Posted
  • Author
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its nothing to worry about mate,

as dan said, its just the usual RB noisy injectors.

thanks for all the help guys!

hopefully my mechanic has made an error in judgement. i have aftermarket Denso 550cc injectors in there too.

will attempt to clean the AAC valve on the weekend to stop the hunt on idle :whistling:

SECURITY Grand Master

SECURITY

Posted
Posted
thanks for all the help guys!

hopefully my mechanic has made an error in judgement. i have aftermarket Denso 550cc injectors in there too.

will attempt to clean the AAC valve on the weekend to stop the hunt on idle :whistling:

sorry mate, i edited my post because i actually watched the vid. sorry.

dan.1337 Proficient

dan.1337

Posted
  • Author
Posted
sorry mate, i edited my post because i actually watched the vid. sorry.

ah that's not my car...that's shanef's.

mine is the ticking description coming from the yellow circle. i dunno how to upload sound.

SECURITY Grand Master

SECURITY

Posted
Posted

oh!!

well then you're a lucky man, i wasnt paying attention. i thought it was yours.

then its noisy injectors mate.

also as a general tip, overfill your oil by around 500ml. T04GTR was running 300ish kw on the standard bottom end and thats all he does. no spun bearings for him.

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