78SilverCam

Evening all,

Have another thread going on gas fumes - but didn't wanna have two issues going on at once (thread wise...)

Today I discovered a scraping sound coming from the engine - was wondering if anyone would have an idea of what it could be - video here:

http://www.youtube.com/watch?v=sHG2_...ature=youtu.be

Thanks for any help!

**do the YouTube codes work?

my 76 ray

I had a noise that sounded like that. It turned out to be the aftermarket chrome torque converter cover that was vibrating and hitting the oil pan. I took it off and bent it a little so it wouldn't hit anything.

CQRT

sounds like bearings - -water pump, smog pump or alternator?

73Corvette

Take an old broom handle cut it about 3 foot long... with the car running start putting one end of the handle on the alternator....then the power steering pump, etc. with the other end of the handle on your ear.....keep searching til you pin point where the sound is coming from if you take your time... many times you can get right on the exact spot the sound is coming from......sound "travels" thru an engine which makes just listening to it difficult to isolate the source...but, with this method you can cancel the excess noise and find the culprit.....good luck. this post will self destruct in 5 seconds........

briankeery

It almost sounds like a heat shroud is loose.

73Corvette

Again.....I think all of the guys are right. Could be any of these things and many more, but, which one is it? If you'll try my broom handle method you might be surprised what you can hear.....good and bad.

briankeery

When the man is right, the man is right.

78SilverCam

lol, thanks guys - will give it a shot.

scottyp99

It kinda sounds like it could be a loose piece of sheetmetal vibrating somewhere, but then again, it could be a bearing destroying itself. (not an engine bearing, don't worry!)

I've never used the "broomstick" technique, I'll have to give it a try. What I like to do is take a piece of 5/8" heater hose, or something similar, like a piece of garden hose or something, and use it like a rudimentary stethoscope. Stick one end up against your ear, and listen, while moving the other end around, looking for the sound. It's great for finding exactly where a sound is coming from, like an exhaust leak, or whatnot, and it's flexible, so you can get the other end into a lot of places you really wouldn't be able to use a broomstick. Try 'em both.


Keep the shiny side up!
Scott

BOSTONCAMARO

I bet on rod bearings 10 to 1

I could be wrong, but know that sound well....you may get lucky and there is some sheetmetal flapping around, the broom stick method will aid you, put on ramps safely, use e brake, block wheels etc, have someone rev while you have broomstick to pan.

A wrist pin usually is not as loud and sounds more ticky, almost lifter-esque....I am betting rods, but could be main bearings.

I hope I am wrong, but am betting it is time to pull the motor...have you drained, change oil, check out the oil that is in it?

It could also be water pump, alt bearings, but usually when they go, they will rather quickly start throwing belts etc...

Regards, Tim

imariver

Disconnect all the belts, start engine again, see if that sound is still there.

78SilverCam

Pull the motor?! It only has 50k km on it (~35k miles) Good lord hope you are wrong on that one.

I bought the vette October 2011, and it had a complete tune up at that time, all fluids drained and topped up.

427basketcase

I always use a hose instead of something rigid, like he said it is a lot more flexible, and transferes the noise a lot better

78SilverCam

I used a broomstick and what I found was that everything sounded great - except for the valve cover near the oil cap.

The other valve cover sounded more like a healthy "woosh-woosh" whereas it the area near the oil cap was more of a tin-like "reeeee"

Tin isn't the exact sound - but it certainly wasn't "woosh" either.

Checked the oil and it was half full whereas last week it was full to the top. Probably because the engine was hotter at the time. Could probably use an oil change - but not mandatory - will do so on the weekend all the same.

Assuming someone doesn't tell me the "reee" sound means something drastic...

78SilverCam

Should also mention that for one start - the sound was gone. But then it came back on another start.

BOSTONCAMARO

Not saying you should automatically pull it, just my thoughts, from what I can hear from a youtube video, online, that there may be a bearing issue in the motor.

I hope I am way off, do what others suggested, remove drive belts, listen, then use broomstick or rubber hose technique to pinpoint noise.

0 miles, 35k miles, 200k miles, doesnt matter a motor can have major issues.

I wish you luck and hope it is something stupid like a loose dust shield somewhere or something.....drain oil this weekend, also drain filter into a pan when it is out...use a dark colored pan to drain oil filter...hopefully you dont find anything

78SilverCam

Acknowledged, thanks for all your input. One extra thing to do this weekend...

666WMD

Does the noise increase/decrease when revving the engine or when under load?

78SilverCam

Well it's been a while - about 2 weeks into a 50k tune-up (don't get much continuous time on the vette).

To the matter at hand, changed the oil. Nothing in the pan or filter of note. New oil in, sound is still there.

Used both hose and stick method - the sound is coming from the driver side valve cover on the engine. It comes and go's for no apparent reason. Will have to do more observation to see what conditions it arises again.

Any one have any ideas?

garage-ghost

Something bouncing around inside the valve cover, hopefully not a rocker.
Just a guess.
I'd be pulling the cover off and taking a look.