This is my buddies ride, what could this knock be?

Reddevil91

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Mar 3, 2010
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Ok this is buddies car, he picked this car up after selling is 13’ rough stage 3. Car was a 93 clone he picked up, which the previous owner installed a 90-91 motor in it can’t remember. Any ways he followed my track, with the powder coating etc. so he dropped the car off to a friend of his who opened a shop, decided he wanted to go turbo bc of the cost, bang for the buck. Car was in this guys shop for over a year before he finally got it back this mid February. So no motor changes really, has 3 bar heads and stock rockers, e cam, nothing crazy, the previous guys basically tried to clone the cobra motor. The car was supposedly street tuned, idk how much boost was added. Car has been back in his hands for maybe a month. He took it out and played around, tried to mess with a new Lexus F body then took it out on toll roads and let it open up. Came home and car is running like this. He pulled the covers and checked the rockers and said all looked good, nothing cracked or loose. Any ideas?
View: https://youtu.be/DviRW3HUqK0
 
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a91what

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listen around the car, is it louder from below? use a long screwdriver or anything you can use as a stethoscope to listen to different parts of the engine.

The optimist in me says exhaust leak, but those usually sound like a tick not a knock.
 
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John Dirks Jr

there is enough sticking out to grab on to
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Use a 4' long piece of garden hose as a stethoscope. Put one end in your ear and move the other around to zero in on the source.
You can pull the upper, pull the valve covers, plug the pcv port and put the upper back on without the valve covers on. Start the engine and move the garden hose end over each rocker arm till you find the one that clacking. You can run the engine at idle without the valve covers and usually get away without making too much of a mess.
 

Reddevil91

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:pop:
listen around the car, is it louder from below? use a long screwdriver or anything you can use as a stethoscope to listen to different parts of the engine.

The optimist in me says exhaust leak, but those usually sound like a tick not a knock.
Meant to say knock not tick lol oops I will tell him. I haven’t been over due to the social distancing. He sent me the vid bc he took the car out and then that happened.
 

Reddevil91

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I think that is not an exhaust leak, hopefully a rocker arm but I'm optimistic about that.
I thought maybe broken or loose rocker to, he said he pulled the drivers valve cover off and said all the rockers were snug. Not sure why I said tick in the title instead of knock!
 

Reddevil91

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Mar 3, 2010
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Use a 4' long piece of garden hose as a stethoscope. Put one end in your ear and move the other around to zero in on the source.
You can pull the upper, pull the valve covers, plug the pcv port and put the upper back on without the valve covers on. Start the engine and move the garden hose end over each rocker arm till you find the one that clacking. You can run the engine at idle without the valve covers and usually get away without making too much of a mess.
Cool I’ll relay this info, he said he pulled the drivers side just to eyeball and all the rockers seemed intact, nothing loose or broken. Could this be a rod knock? Not sure what that sounds like
 

General karthief

wonder how much it would cost to ship you a pair
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I can understand the need for possible problems the offending noise is caused from but in reality a recorded sound broadcast through the internet to different devices is kinda, well, pointless?
Like 'how does my exhaust sound?' 'dude your exhaust sounds like crap because I using a 10 year old kindel with spaghetti taco debris in the speaker holes!'
So I will give you a list of possibilities, keep in mind this is just my opinion and not based on any real mechanical experience:
Spun rod or main bearing, loose converter or flywheel bolts, loose crankshaft pulley.
Less likely: bent push rod, broken piston skirt, debris inside the cylinder, loose nut behind the wheel.
I feel bad for your friend, but it is not the end of the world, just devastating to the ego and the wallet.
He will be digging deeper into this engine so keep us informed as to what the results are, inquiring minds want to know.
 

Reddevil91

10 Year Member
Mar 3, 2010
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I can understand the need for possible problems the offending noise is caused from but in reality a recorded sound broadcast through the internet to different devices is kinda, well, pointless?
Like 'how does my exhaust sound?' 'dude your exhaust sounds like crap because I using a 10 year old kindel with spaghetti taco debris in the speaker holes!'
So I will give you a list of possibilities, keep in mind this is just my opinion and not based on any real mechanical experience:
Spun rod or main bearing, loose converter or flywheel bolts, loose crankshaft pulley.
Less likely: bent push rod, broken piston skirt, debris inside the cylinder, loose nut behind the wheel.
I feel bad for your friend, but it is not the end of the world, just devastating to the ego and the wallet.
He will be digging deeper into this engine so keep us informed as to what the results are, inquiring minds want to know.
Lmao well clean that dang speaker screen!! In all honesty I get your point, it is hard to diagnose via video. I’ll relay some of these points here and see what he finds out and give an update. Appreciate everyone trying to help out. Now I’m back to figure out my doors and weather strip and striker bs!!
 

Reddevil91

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My buddy went and got an oil pressure test gauge. Connected, cranked and states there was zero oil pressure. Still knocking, and drained the oil and no shavings or chunks.
 
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Steel1

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Unfortunately it sounds like this engine needs to come apart.
He could cut open the oil filter and inspect but with no oil pressure It's only a matter of time before it eats itself.
 

2000xp8

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My buddy went and got an oil pressure test gauge. Connected, cranked and states there was zero oil pressure. Still knocking, and drained the oil and no shavings or chunks.
Literally zero by removing the sender and connecting the new gauge?
One would think that it would at least show something at cold start up.

Is it too soon to suggest jack stands? J/K (sort of)