Rod Knock?
 

Ok so im still trying to figure out this Rattle. Its more of a knock so ill call it that.
The car idles PERFECT. No obsurd sounds, no shaking, really no problems.
If i rev the car to just about 2.5k rpm it makes a knocking sound, i listen really closely and it sounds like its coming from cylinder 4.
If this was rod knock, would it be only happening at 2.5k and above? Or would it affect idle?
Is there any tests to check for rod knock? Can i take off the oil pan and be able to wiggle the piston or something? Im really freakin confused, and if this is in fact rod knock, im parting out the car. But it would really like to sell this as a whole and be done with it.
Just a few notes:
New timing belt, New revised lifters bled etc, new clutch, new head gasket.
Thanks in advance. Ill try and capture the sound on video and post it.

Re: Rod Knock?
 

It very well could be. Drain your oil and look for metal particles, it could be a few things, none are good.

Re: Rod Knock?
 

Can you name a few of the things it could be, it would be very helpful. I just need some places to look? The oil is clean, i have replaced it 3 times in the past 2 months. Made sure it was clean. no metal flakes, nothing.

Re: Rod Knock?
 

I have delt with that same sound and also occured over a bit higher rpm then idle and both cases was a bad rod bearing. Take off the oil pan and look for shavings and you should be able to grab the nut on the lower portion of the rod and yank back and forth and it will more then likely have play.

Re: Rod Knock?
 

If this is the case, can i replace the bearings without pulling the block?

Re: Rod Knock?
 

sure can... but the rods will need to be checked to make sure they are in spec, witch you would have to pull the head off to do

Re: Rod Knock?
 

it also depends if it has chewed on the crank

Re: Rod Knock?
 

im gonna try and pull the oil pan tonight and pull the bearings, ill post pics.

Re: Rod Knock?
 

Yeah, likely the crank won't be in good shape either. It sounds like you caught it pretty early though, so you might be in luck.

Re: Rod Knock?
 

Yeah ive been driving it really easy, no shifts over 3k. (and i actually mean that...) Plus i had been breaking in the clutch (just hit 300 miles) so hopefully all is well with the crank. Im at my wits end with this car.
After the new bearings, is there a break in period? also what do you guys suggest for the replacement bearings? And should i use some kind of lube on the bearings before putting them in or some kind of prep?

Re: Rod Knock?
 

I'm using ACL race bearings in my car. They weren't too expensive, and they now have about 25k of not so easy driving on them. You will wanna use assembly lube on them when you put them in, and make sure there is no scoring on your crank. As for a break in period, you'll wanna go pretty easy on the throttle and rpms for about 500 miles, then change the oil. Then change the oil again after 1000 miles, then after that you should be good to give it hell.

Re: Rod Knock?
 

Bah, 100 miles is about all I do for break-in anymore. That 1000 mile stuff pertains to old Chevy motors.

Re: Rod Knock?
 

I am with Steve, I did about 100 miles too, but I did do 3/4 throttle at low boost after 50 miles to make sure the rings were seated. I was only fairly nice to it for the first 20 miles. I was also very picky on my clearances during assembly.

Re: Rod Knock?
 

Yup its verified. Rod bearings were the problem.
Crank and Rods look fine. The bearings still had a little copper (looking) on the crank side.
Im ordering new ones tomorrow.
On a funnier note, I found a 10mm socket in my oil pan. Not sure how it got in there.

Re: Rod Knock?
 

Was there alot of shavings? If so you might want to clean everything out to prevent any further damage.

Re: Rod Knock?
 

WTF? Have you ever take this motor apart before? Or was it the previous owner who did that?

Re: Rod Knock?
 

Im thinking it was the previous owner. I havent taken the oil pan off before in this car. :) it was just chilling on the bottom of the pan. Its funny though because it scared the hell out of me when i was hearing it drag on the bottom of the pan i was thinking it was something much worse. LOL

There was some shavings on the bottom of the pan, ill make sure everything is cleaned up. and do an oil change.

On the crank, cyl 4 there was a very slight scoring on the crank. I dont think it justifies replacing or returning the crank. The other 3 looked just fine. On cylinder one the top part of the bearing was broke in half. YIKES. Good thing i didnt wait any longer. Surprizingly cyl 1 does not have any scoring whatsoever.

Anyone know the torque specs for the rod bolts? I couldnt find it in my manual.

Also i definatly suggest to everyone, if you ever have your oil pan off, replace the rod bearings. its very easy to do and could fix a disaster.

Re: Rod Knock?
 

Free socket for you!
Sounds like you got pretty lucky. Are you going to pull the head and check everything out or just replace the bearings?

Re: Rod Knock?
 

Im just going to replace the bearings, i dont think i need to check the head.

Re: Rod Knock?
 

You really should take everthing apart and get it all cleaned, some shavings could have went through the pick up and now are in the rest of your engine/turbo/oil cooler.

Re: Rod Knock?
 

There is no possible way that could have happened.
Shavings drop straight down into the oil pan, they would be picked up by the oil pump then filtered by the oil filter. (which is why im changing the oil and filter. )

Re: Rod Knock?
 

I would not run a crank with scoring that can catch a finger nail.

Re: Rod Knock?
 

Yeah it's not that bad. like i said only very light scoring.

Re: Rod Knock?
 

Hate to say this, but what's the over/under on the time until Tom reports a spun bearing?

Tom, do it right or don't do it at all. Don't let us end up telling you "I told you so."

Re: Rod Knock?
 

Good thing someone posted this.

Re: Rod Knock?
 

Took the thoughts right out of my head...

Re: Rod Knock?
 

I am doing it right. If it was a concern at all you would see a thread dedicated to my parting out the car.
We are talking about very miniscule (almost like a scratch.) You cant catch your finger nail on it at all. Cant even really feel it with your finger. There should be no problems associated with this. I dont see any reason to have to pull the entire motor to take out the freakin crank because of a scratch. Theres doing it right and theres over doing it. That would definatly be overdoing it.

Re: Rod Knock?
 

Well let us all know how its ends up, hope everything goes as you plan.

Re: Rod Knock?
 

Have fun spinning a bearing. :)

Those scratches are imperfections in the journal surface. The bearings don't ever actually touch the journal, they are always separated by a thin film of oil. Any sort of scratch means there is imperfections in that surface making it more difficult for the bearing and journal to stay separated. It won't fail immediately unless there is assembly error, but you can't deny that it won't shorten the life of that bearing.

Re: Rod Knock?
 

^ what matt d said. :banana: