knock / rattle from engine....possible rod????

[ultimatesho]

i replaced my old rear exhaust man. that had the hole from were it had the EGR, so now im noticing every little noise.....lol

im not positive what the sound is kinda sounds kind of like a hollow metal on metal rattleish knock, its only there at idle part of the time, and "usually" from about 2k-3kish...........dose sound to follow the rpm's for the most part

i know my secondaries rattle, and i have a noisy injector......so it may just be one of them

i did the RB's 14k ago so i dont c why they would of went that quick......everything looked good inside wehn i changed em, other than the old bearings were fairly worn

i used a long extension and listened around on the engine and the only place i can find a noise coming from is the fuel rail from the injector.....listened all over the bottom half of the engine and dont hear a thing

anyone got any ideas what it could be???????need to do a oil change sunday and i plan to drop the oil pan just to check em and see if its is from there or not

 

[92MTX]

Is it coming from the timing chain cover area??
Rod knock usually sounds more like a hammer hitting something metal..
When the tensioner acts up, it can sound like a rod knock..
My ATX scared the **** out of me like that.. Thought I had a bad bearing..
I popped the hood and checked closely, and it was coming from the cam chain cover..

What I did was to pour a can of Berrymans, and half a quart of tranny fluid in it, and let it idle (DONT drive it like this..) for about 30-45 minutes.
When I did this, the noise went away..
Changed the oil, and substituted a quart of TF..
Drove it like this for a few days, changed the oil again, and never had another peep out of it..

I think this is from the P.O. using crappy oil.. Probably Dollar Store oil...

 

[ultimatesho]

ive never been able to find or even hear the noise at idle with the hood poped.......about the only time i can even hear it at idle is when im besides someone at a light or next to buildings or somthing

i did listen to the valve cover though to check the tensioners and i heard absolutely nothing from there

with this car every since ive owned it (going on 2 years now) ive ALWAYS used Mobile 1 filters and Mobile 1 oil

 

[St Louis SHO]

Throwout bearing? Press the clutch in and see if it goes away.

 

[ckinney89sho]

heat shield maby or a tool that might have been left in there from the exhaust manifold. what side of the engine?

 

[ultimatesho]

pulled the oil pan today........caps, rods, and crank all look perfect

the other day i intentionally about stalled it taking off from a red light just to see what the rod sounded like for sure when it knocked, and the sound the cars making sound alot like it to me now.......but nowere near as loud

and its not the TOB James........done checked that a little while ago just in case

any other ideas?????......would the main bearings possibly be a option????.......would they sound like a rod knock if they was on their way out?????

 

[geomarathoner]

Since you've replaced the rear exhaust manifold, have a close look at the bottom ****** where it connects to the cat pipe. On my '89, after I installed a shoshop hiflow cats ypipe and a Borla, I noticed an occasional clunking at that same rpm range and it turned out to be just a minor contact when the engine torques/moves on the mounts. The new ****** is just a tiny bit larger than the original. I noticed a small shiny polished spot. Ground a little off and that didn't totally eliminate the occasional noise but at least I stopped worrying about it.

 

[NEp8ntballer]

Since you've replaced the rear exhaust manifold, have a close look at the bottom ****** where it connects to the cat pipe. On my '89, after I installed a shoshop hiflow cats ypipe and a Borla, I noticed an occasional clunking at that same rpm range and it turned out to be just a minor contact when the engine torques/moves on the mounts. The new ****** is just a tiny bit larger than the original. I noticed a small shiny polished spot. Ground a little off and that didn't totally eliminate the occasional noise but at least I stopped worrying about it.

does it sound kinda like somebody shaking rocks in a can only more metallic? If so it's the cats.

Might have a loose heat shield. if you don't have an oil pressure light coming on then the rod bearings still should be good.

 

[ultimatesho]

i pulled the pan last weekend and everything was perfect.......

as far as cats go, theyre gone......lol

the noise is still there tho, so all i can think of is like was mentioned a heat shield flapping around......after it dries up some outside im going to check all them and c if theyre loose anywere

not really a issue now that i know its not the bearings or rods

 

[CademiaX]

I have something like this going on AFTER I did my rod bearings. They were going, but wasn't the source of the sound. I am going to do a front 60K soon just so I can replace everything in there. Think it might be the timing belt tensioner or crank cancer.