Please help guys, do I have rod knock?

Alpha WereFox

Supraholic
Aug 20, 2006
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Alright I'm going to explain this the best I can to you. I traded my Subaru a week ago for the 87 Supra. The kid lived 2 hours away in NJ, I live in PA. When he got to my house the Supra was tapping. I figured ah fook it, if he made it this far the car shouldn't be that bad. I've seen the car 6 months ago when he came up to show me it but it didn't have this issue.

So anyways it's been a week now and I think I put about 400 miles on her since the trade. I drive about 40 miles to and from work everyday. The knock hasn't gotten worse. The kid had 5/20 oil in but the day I got her I put in 15/40. The knock/tap went away. Next day it came back and hasn't gone away since. The car seems like it has all it's power, it doesn't hesitate or anything. And after like 2k RPM's I don't hear the knock anymore. Oil pressure seems normal to me. Normal driving its like at 39. At a constant 4k RPM's its at like 63ish or so. Is that good? I have no idea, thus is why I'm here. The knock is sometimes loud, and sometimes not that bad. And the knock is a random beat, it's not like a perfectly rythem. I'll try to take a video or something of it running so you can hear it but I'm at work and can't do it till I get home in 6 hours. Then I'll post a vid on YouTube. Also, I bought it to like 5.5k Rpm's through the gears a few times to show my friends her power and such and it hasn't thrown a rod or anything so I dunno what it is. I figured if it was a rod knock I'd thrown the rod by now right? Anyways please give me any kinda info you can. This is my 2nd Supra and I love them to death. It took me too long to get another one to let this one go too easily.

Say hello to Nana Maru!
(means "Seven Zero" in Japanize, last owner named her)

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(Wing will be painted probably today after work to match car)
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suprahero

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Aug 26, 2005
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Definately need a video, but the sound should be rythmic. Does it get louder or faster upon acceleration? When you are at the hood and rev the motor by hand, does it get louder? Why would you be revving it to 5500 showing your friends what it will do if you think you have rod knock? Post up a video and we'll go from there, but don't drive it unless you have too, and don't try and throw a rod through the block just to prove it has rod knock. You can still fix it relatively inexpensively if you don't hurt anything else.
 

Alpha WereFox

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Aug 20, 2006
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No I musta typed it wrong, I was giving friends test drives, not revving it at that. But the knock doesn't get much louder, just faster I think. I'll make a vid when I get home. Thanks for the reply. And I hafta drive it or I loose my job.
 

suprahero

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alphawerefox;1036769 said:
Also, I bought it to like 5.5k Rpm's through the gears a few times to show my friends her power and such and it hasn't thrown a rod or anything so I dunno what it is.

I'm pretty sure through the gears doesn't mean taking them for a sunday afternoon ride..........:biglaugh:
 

amichie

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Apr 13, 2006
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If it goes away after 2000 rpm then its not rod knock. Rod knocks get louder at higher pm and at higher load.

Check for exhaust leaks around the manifold.
 

GrimJack

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RK is simple to diagnose.

Park it, fire it up, find a spot in the RPM band where it's knocking, then pull and replace the plug wires one at a time.

If one of the plug wires makes the sound go away, that cylinder has rod knock.
 

suprahero

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IJ.;1037142 said:
Injector clips hurt less ;)

Pansy..................... don't :ban:

Knock knock

You can still do as IJ and Grim said to make sure, but it sounds like rod knock to me.
 

Alpha WereFox

Supraholic
Aug 20, 2006
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Poconos in PA
I really cant take a decent vid till my sister or her b/f gets home with the dell laptop with built in cam and mic. Give me a bit for a better vid folks!

Goin outside now to paint wing to match body.