My motor has been knocking for a while now, right after i installed my new longtubes and catted y pipe...I changed out my manifold gaskets and that helped a little bit. I'm unsure how to describe the knock so I'm gonna post a video. I opened the valve covers and started the engine and everything seemed to be fine. I checked my oil for metal shavings and that checked out. So I'm unsure of what to do now. I cant remove my heads or oil pan due to my apartment complex being a-holes. Anyone have any idea what this could be?

Thanks in advanced

http://www.youtube.com/watch?v=0Dify...el_video_title

 

thats internal. WOULD NOT START THAT UP AGAIN. Sounds like a bent rod or loose rocker. I would remove the rockers and check your rods to make sure nothings bent up. If not that, could be a bad valve spring. You should work your way down al te way to the cam. last thing you need is to spin a bearing.

 

That sounds gnarly, good luck with everything.

 

sounds just like my car kinda goes away when u give it gas i should be finding out what it is tomorrow engine is getting pulled out tonight but i think it a rod bearing

 

if it goes away with rpm i'd start checking the **** in the bellhousing. have you had it apart recently?

if you checked the oil and didn't find any flakes...i'd guess the engine is ok, at least at this point. did you cut open the oil filter? it doesn't sound deep enough to be a bent rod or spun bearing, but it's very hard to tell on this laptop with it's 5 year old .00000025" speaker.

 

I'm friends with Mike and have heard the knock in person. We checked all the valve springs, rockers, pushrods... the only thing I can maybe imagine is a lifter??? There are no metallic flakes in the oil. we checked it numerous times. It's beyond strange. And if it was a rod or such, I think it would HAVE to be more constant... but idk. What do you guys think about the possibility of a lifter???

 

It does'nt sound like a rod bearing to me . It sounded like it was on top side of motor . Whenever You hear knocking in an engine , first thing is jump down and listen to oil pan and feel oil pan , then shut it down until You figure it out . You said it had been knocking for a while , a rod bearing will only go that way for maybe a week if You change the oil to valvoline racing straight 50 or 60 weight , Good luck

 

wrist pin!!!!! flywheel cracked maybe!

 

I agree with chris, dosn't sound like rod knock to me. What happens when engaging the clutch?

 

pull your valley cover off look in there u can kinda see the lifters through their my car wasn't pulling any metal shavings on the dip stick either but when they got the valley cover off he found bearing debris in mine

 

That's the same exact noise mine is making. Here's the thread I made

https://ls1tech.com/forums/generatio...sue-video.html

Newest vid is on page 2. I've swapped lifters three times thus far with no luck. After it warms up it makes the exact noise yours does...where it will intermediately go away for a second or so, and sometimes goes away on decel.

 

Well it started knocking when I was running with another car and I downshifted so I'm not sure if it's a cracked flywheel. But The clutch feels fine to me.

 

That is pretty damn loud...... however we just had an issue like this with a motor rebuild with a supercharger on a GTO. Motor ran great for 600 miles didnt make a peep..... but somehow metal shavings or some sort of metal got sucked down into the number 4 cyl..... sounded just like this changed with rpm and everything. Pulled the head off and there were dents in the piston and a piece of metal sitting in the cyl.

Just my 2 cents. But when you rev it it kinda goes away so I dunno if I would say rod knock but thats def quite audable.

 

Sounds like a rod to
Me. He said he checked rockers

 

Loose crank pulley?

 

A rod bearing issue would'nt go away with rpm , just get louder . So last poster is probably right on the fast money .

 

Pull off the valve cover and run it and watch to see which rocker is not getting oil. Check the valves too to be sure none are getting stuck in the guides from being bent etc. This noise should be easy to find. I'm guessing dirt in a oil passage or in a lifter or bent valve etc something that is causing play in the valve train some place causing the noise. As loud as this is with the valve covers off you will find something wrong.

I had the exact same noise and it was a blocked dirty lifter.

 

i dunno sounds eerily similar to my engine when i lost a rob bearing but if there aren't shavings in the oil i dunno.

 

I agree, my first ls1 that I was told was good, made identical sound... when rpms went up it would get quiet for a second or so but come right back at idle.... had two spun rod bearings....

 

Noises in aluminum engines are very hard to diagnose, It could so many things. I had the exact same noise and it was a lifter. I also have terrible piston noise at lite throttle and if I let off the throttle at light throttle the engine rattles like a box of rocks. My oil is clean with no sign of metal and has been doing this for 50k miles.

The noise above sounds like a lifter to me but anything is possible, I woooood check the valve action running with the valve covers off. If its a lifter you will be able to find it because the rocker will be loose as it goes up and down. Also you may find no oil coming out of the rocker. You could also start pulling plug wires one at a time if you think its a rod bearing to see if it gets quieter without a load on the cylinder.