Rod knock or noisy head?

M

mk3-4-me

New Member
May 19, 2010
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So I just got my supra registered and Plated... I just rebuilt the motor last year, and just got it all running good...

I just started it up, getting ready for the first drive to somewhere other than around my neighborhood for the first time. Anyways after it warmed up, I was givin it a lil gas and at around 2.5 k I noticed a noise.

I never personally dealt with rod-knock or heard it in person (I've youtubed it).

Now my head has always been noisy, and ive done some searching and it seems that 7m heads are always a bit noisy.

I was just winderin some input on how to tell if it's rod knock... No noise at idle and any higher...

It's just gunna suck to see that right after I got it rebuilt, registered and plated, it gets rod knock.

It's never been low on oil, I used 10W40 GTX oil for the break in. I was a lil hard on it around my neighborhood, after driving it easy a couple times. After reading around it seemed that easy vs. Hard break ins work out the same, so I hit it a couple times... I couldn't wait :cry: lol... Idk.



Just looking to see if you guys think it's a rod knock. Or if there's hope for the supra....
 
radiod

radiod

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Dec 13, 2007
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A big cause of rod knock in these cars is coolant in the oil. When a head gasket blows it can dump coolant in there and that will score the bearings up on the bottom end pretty quickly. If the bottom end isn't taken care of during a head gasket job it's not uncommon for rod knock to soon follow.

Rod knock is a pretty solid knock coming from the block. It's like someone's tapping with a hammer on the inside. You can typically hear it the most when the engine is warm and the oil is thinner. Sometimes you'll hear a flutter of it when the rpm's are changing from climbing to falling if you blip the throttle to between 2000 - 2500rpm. Once rod knock starts it unfortunately just goes downhill from there. The extra clearance that causes the knocking noise gets bigger because of the knocking until one day (if you leave it long enough and rev it high enough) exit rod stage left through the wall of the block.
 
M

mk3-4-me

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May 19, 2010
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Idk I was just listen to rod knocks on YouTube and mine doesn't sound exactly like that and it's not as loud as any of them. I'll check it out again 2morrow, listen and try to figure it out.

There hasn't been coolant in the oil. So it's prolly not that... Hopefully...

I just hope it's not RK.
 
enjoi.this

enjoi.this

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Aug 18, 2008
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the heads on 7m's do make some noise but its more of a rattle or ticking sound. Rod knock is a pretty distinctive knocking sound
 
M

mk3-4-me

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May 19, 2010
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All I have right now is my iPhone... I can try and see if you'll be able to hear it on it.

I know the head makes the sorta tickin noise, and the noise I noticed coulda just been me sketching out... Lol

I do have a couple exhaust leaks byt the turbo and DP. So I guess it could be that to.

And I rebuilt the engine.
 
mecevans

mecevans

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Jan 18, 2009
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40 weight wont kill your motor but it also doesnt do any good. Unless you have crazy oiling mods 5w-30 is what you want. Once you warm it get a long screwdriver and place it on differnt areas of the engine. Stick your ear on the other and listen, but be watch out for anything rotating. You should be able to pinpoint it.
 
M

mk3-4-me

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May 19, 2010
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Ya but aren't you supposed to use thicker oil for the break in? That's y I am using 40 weight now, I'll be going to Ams Oil fully synthetic after about 500 miles or so...
 
mecevans

mecevans

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Jan 18, 2009
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Nope. Im using the walmart 5w-30 ISLAC-5 oil. I got about 200 miles on it and plan to change it around 500 and go full syn too. If its not broken in by then something is wrong and its time to rering it.Changing it too much is BAD and a waste of money.Your filter there to get particles out and once it gets to ops temp it will burn off any crap. When you change it to much you get way to much addatives and detergents left behind which causes ring seal problems.
 
lewis15498

lewis15498

Don't blame ebay cheapass
Sep 28, 2008
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If you want useful advice here, you should list everything you have done to the car since you bought it, as well as any info you may have obtained from the previous owner. This would include what this rebuild you performed consisted of.
 
KicknAsphlt

KicknAsphlt

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Nov 20, 2005
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I had what I thought was rod knock on my motor (still not fully confirmed), so I yanked it, tore it down, and rebuilt a spare block. When I pulled the main and rod caps though, the bearings looked damn good for a 13x,xxx motor; however, when I pulled the cam caps, it looked like someone took a die grinder to the cam journals. The reason I say the rod knock is unconfirmed is because I haven't gotten around to mic'ing/plasti-gauging the bearings yet.
 
M

mk3-4-me

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May 19, 2010
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Ok so I rebuilt my motor backto stock. All within spec of Alldata. Honed cylinders so there is no taper top to bottom, resized connecting rods to spec, put all new bearings and evrythin.

The P.O had put n/a injectors in and melted a hole in a piston, but the crank journals were all good and within spec.

I dnt hear or notice anything when driving, but that's prolly cause I have so many exhaust leaks.. Lol

It really only makes the noise on start up, when it idles a lil higher. Yesterday when I heard it, it kinda sounded like the rid knocks I heard on YouTube, but not as loud and not exactly like it...? Idk but the noise would almost sound like it's speeding up and down a little while my rpm's stayed steady at 2100.

The motor runs strong, it's only seen 8-9 psi a few times but mostly just easy driving. It doesn't vibrate or anything that I can feel.

Idk if that helps you out, but thanks for helpin me out.
 
M

mk3-4-me

New Member
May 19, 2010
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Milwaukee, WI
Re: Rod knock or noisy head?
You sure you're not hearing piston slap?
Click to expand...

No lol Thats y I'm askin... never experienced that either so idk what to listen for really. Is it when I hits a valve or something?

I forgot to say I do have a code 52. I'm gunna be doin the rewire this weekend. Could that have anything to do with the noise? Predetination noise? Idk I'm just tryin to think of everything it could be. Maybe my timing is off to, and that with the code 52?
 
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