I posted this originally in the maintenance section but got little response,. Probably should of posted here is the first place. My mistake...

Anyway,
This is on a cold start. I'm using 0w-40 Mobil1. My oil level is a little low. Slightly under half. You can hear the slip on my serpentine belt (not an issue), but the knock is. Is this the sound that my timing chain or chain tentioner not full of oil as i've read? OR does this sound like a valve lash issue OR spun rod bearing?

I'm considering removing my oil pan to look for metal. Where to go from here?






Is that oil getting into my coolant?

http://s66.photobucket.com/albums/h2...ent=knock2.flv

 

It's really hard to tell from that audio. It doesn't sound like a rod though. Sounds more like valve tap.

Also the oil in the coolant is not good. Are you getting any smoke out the tailpipe? What color?

 

Valve tap sounds a lil higher in pitch than that.

OP do something, with engine on, linstening to the same sound, put ur head near the bottom of the car and see if the noise is louder down there, that will tell you if its most likely rod knock or not. I had almost an identical sound, ended up with pieces of oil pan falling onto the street. =(

In my case I put in a vq35 that I bought at a local junk yard, from the 1st time I started her I heared that sound, i ignored it since i know our VQ's are noisy, figured it was just cold start, and random sounds. about a week n half later I was noticing it louder, got a lil worried but still drove the car around, then on the highway cruising, i get on the gas a little bit to get into boost and test out the motor, noise got real loud, pulled over n sounded like death!, slowly drove off the highway and as I was getting close to my destination at a friends house the noise went away and BAM!!! I could hear pieces of the oil pan hitting the floor. Turns out it looks like the motor had been hydrolocked or something because the rod that broke was bent alot, so with every stroke it would hit the side of the piston where the pin is at. Rod broke right in the middel closer to the piston.

Dont ignore this and try not to drive the car untill you have determined what it is. I would take out the upper oil pan and inspect, move the rods around n stuff, see if there is play in the bearings.

 

is it a built motor??.. id go straight to gtm. hard to tell but whatever it is.. doesnt sound good

 

Sounds too deep to be a valve. But doesnt sound like a rod either. Whatever it is, It doesnt sound good.
Check to see the Actual color of your coolant. If it is like creamy, or peanut butter colored, you def have oil in it. and if thats the case It could be ALOT of things.. from a head gasket to a cracked block.
I see that your car is FI. so you should be running heavier oil and never run it low. Prolly the cause of you problem. Especially since you hafto run more than recommended for you FI. Either way, sounds like the engine needs to be torn down.
I would suggest to start, a compression check. That will let you know if your valves are seating all the way for one to eliminate whether or not it could be valve tap.
If that doesnt help Tear the heads off and send them to the machine shop to see if they are warped. Than all you can do is work down from there.
Its prolly going to cost more than it's worth if it goes past a compression check.
Start shopping for a new motor IMHO. Sounds to nasty to try and diagnose. It will prolly nickle and dime you to death.
Pullt it out, get replacement motor, then go fully built on that tear down if the blocks all good!

What does your oil pressure gauge read when car is warm, at idle?

 

does sound change with rpm? i.e. as rpm's go up does tapping increase, not change, go away?

Tom

 

Im willing to bet its rods/bearing. If he does what i said and listens below the car and it actually is louder than uptop, it HAS to be rods. Sounds almost identical to mine.

 

I agree its still rodknock.

Tom

 

Doesn't sound good, OP

Hoping for the best.

 

Rod knock...shut it down before anymore damage is done.

 

Look at the pulley towards the end of the video, with each knock it's jerking the engine enough to move the pulley...shut it off! Hole-in-block eminent!

 

Is this a built motor? If so it shouldnt have blown with a regular SC at 2.87 pulley unless the tune was way off. GL.

 

I am going to go through each of your suggestions this afternoon. Yes it is a built motor. To far to drive to GTM, only about 60 miles but not in this condition. Yes it's rythmic so it increases with rpm.
Going out to lift my car right now, Try streetlegengz idea. Just put my ear down at the oil pan. Pray for me that it's not a rod bearing. : )

 

God that sounds horrific.. I hope n pray to the car gods my car never makes that noise......
Good luck finding out the problem. Id say sounds like rod knock.

 

I say, pull oil pan and look for debrit...sounds like you will find plenty.....unfortunately

 

no need to remove the oil pan, There is a tool that cuts the oil filter in half..

 

tow it to them........rent trailer?

-J

 

I say you talk to your builder before you do anything to the car, they might be able to cover something or help, who knows.

 

sux dude. hope u get it squared away.

 

1500 miles ago I had an oil change. Oil looks very dark imo for only 1500 miles. The knock has been there since I bought the car in December. Just sounds like its getting louder. (maybe due to low oil level, *shrug*)

My question is: Could my last oil change, (1500 ago, which was my first since I bought the car), could it have expelled all the metal bits from a spun rod bearing, just an oil change alone? Because I don' see it here. I didnt do the last oil change but ran my finger through the oil at that time and no metal bits. I should have 1500miles worth of bits here at least though right?
I'm finding very very little metal bits here. I mean just a couple flakes and I've spun a rod bearing in a V8 before and I know how much mess it makes and i'm just not seeing it here.
Also I dont think I could put this many miles running on a spun bearing without my engine rattling apart. I'm going to put a magnet on my drain plug, epoxy it on I think. But why is my oil so black!!??
Check out the vid on the next page and tell me if you think this still could be a rod bearing. I really don't want to have to pull off the upper alum oil pan if the problem is not down here.
Thanks guys

looks ok so far : )




http://s66.photobucket.com/albums/h2...=oilpan003.flv