Knock Noise @ 1900 RPM??

ben42391

New Member
Aug 20, 2009
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Greenwood
Well I have a problem, my car an 89 Turbo If i rev the car to 1900-2000 rpm it has knocking or tapping noise not a rod knock or a lifter. There is no noise above or below 1900-2000 rpm anyone have any idea what this could be?
 

trydrew

Suprafied
Nov 4, 2005
1,038
0
36
Earth
Try to pin-point where it's coming from with some sort of stethoscope. If nothing else, use a screwdriver (preferably wooden handled) pressed against your ear, with the other side touching the motor. Just be weary of moving parts.
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
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Valley of the Sun
ben42391;1414696 said:
Well I have a problem, my car an 89 Turbo If i rev the car to 1900-2000 rpm it has knocking or tapping noise not a rod knock or a lifter. There is no noise above or below 1900-2000 rpm anyone have any idea what this could be?

How do you know this?
 

Mastapip

New Member
Apr 20, 2009
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Ft. Worth Tx
Mk3Tmoney;1415205 said:
I had the same problem with Rod Knock. Turned out I had a spun bearing. Check your oil too.

My first thought too was check the oil. If you're running too low on oil, sometimes you can get a rattling noise from the head. Doesn't necessarily mean it's rod knock though. Check your oil levels and pressure.
 

ben42391

New Member
Aug 20, 2009
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Greenwood
I have a full 3 in back to a flowmaster(bought with it). The oil is fine it was a couple of quarts low but filled and the noise still exists. The Pressure is right below 40 while running but it's a little low when idling. What I don't understand is there is no power loss or anything else of that nature:/
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
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Feb 10, 2006
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You ran it a "couple quarts low"? Do you realize all it takes with oil low like that is one good sustained turn (like on a highway overpass curve) or a rapid acel/decel and the oil pick-up gets uncovered? That means your rod bearings go without oil for xxx amount of time. Guess what? Rod knock manifests itself right at 2000 RPM, especially under load.

You won't have a power loss either...at least until the rod goes out the side of the motor.

I still can't figure out this:
ben42391;1414696 said:
If i rev the car to 1900-2000 rpm it has knocking or tapping noise not a rod knock or a lifter.

Specifically, what makes you say that.
 

ben42391

New Member
Aug 20, 2009
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Greenwood
jdub;1415312 said:
You ran it a "couple quarts low"? Do you realize all it takes with oil low like that is one good sustained turn (like on a highway overpass curve) or a rapid acel/decel and the oil pick-up gets uncovered? That means your rod bearings go without oil for xxx amount of time. Guess what? Rod knock manifests itself right at 2000 RPM, especially under load.

You won't have a power loss either...at least until the rod goes out the side of the motor.

I still can't figure out this:


Specifically, what makes you say that.


I've talked to a couple of buddies that have mkiii and they say its not they have also heard it
 

black89t

boost'en down 101
Oct 27, 2007
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humboldt, ca
retorque the crank pully.


when i had rod knock on my first supra it got a little over a quart low ONCE. that was all it took. then a couple months later it went after knocking for those months. on teardown the bearing was about as thin as a piece of paper. that block lives on though. :biglaugh:

not to say its rod knock but if you ran it that low its more than likely.
 

Clint

AzSupras
Apr 4, 2005
1,463
7
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Mesa, Arizona, United States
Congrates your in denial :), its okay every MKIII owner goes threw some case of denial in there experince with owning a supra...

Your "buddys" are just trying to not make you freak out is all :).
 

87fullKaminari

New Member
Jun 14, 2009
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New Jersey
You might not believe this, but I had a rod knock noise around that RPM and it was a loose harmonic balancer.I assume it wasn't wasn't assembled right after a timing belt replacement (like forgetting the key?) I didn't do it.
 

Turbo Habanero

New Member
Apr 28, 2009
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how do you let it get that low thats crazy i check my oil every other day but im a little crazy myself but i can't afford for my motor to go on me good luck man the first step is accepting the :kickinthenuts:
 

IndyMK3

I Hate Godzilla Too!!!!
May 15, 2008
323
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Indianapolis, Indiana
i have the same problem... lol its just funny how we are both from the central Indy area...

yea i always check my oil and it has always been full.... so idk.... i am just gona pull the motor here soon and check all the bearings... and go from there...
 

7down-7m

Member
Jun 11, 2006
59
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milton
rod knock .. i had same problem but mine was at about 2200-2500 rpm . .the longer u go without taking care of the problem the louder it will get . .i drove 2 years with mine knocking until one day it just went out completely . .now it sitting in my driveway with new motor with some troubleshooting to do still
 

89supra7mgte

New Member
Sep 20, 2009
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colorado
Not sure if this will work on a supra but it does on the 3.0 v-6, I found a rod knock by grounding out plug wires with a test light. I guess depending on the severity of it it will work. Get it up to your "knock" rpm and simply ground one wire at a time. If the knock goes away, you might have a bad bearing. It worked for me. It kills the cylinder taking the load off the bearing and crank