Wierd leak noise developing to Knock.

vasman · 10-25-2009, 09:59 AM

I had a couple of hard runs on Friday. Noticed nothing. Saturday morning a leak noise when I started the car cold. It is definitely rpm related.

I though it was an exhaust leak, as the noise almost went away when the car warmed up.

Drove abt 70 miles without a hinge, just some saddle leak noise when they where obstacles on the side of the car to bounce the sound.

I had one more hard acceleration. The noise got louder. It almost sounded like I had a couple of canaries under the hood, chirping when the car was under normal load (like when you start rolling on first ) and now some on deceleration when in gear. Definitely rpm related (not speed). Checked under the hood, it is not any of the belts.

I thought it was leaking air from my oil-air separator. This morning I bypassed it and with the car cold I started the engine. I got a loud clanking noise (rpm related). As the car warmed up the clanking noise was gone, however I drove the car around the block and the leaking sound now mixed with some metallic sound is there, when the car is under any load.

I am thinking valve, piston rod,?

I have been supercharged for abt 2 months (3000 miles)
The temperature here just started getting in the 40's here in the mornings.
I have dynoed with temperature in the 90's producing 435 rwhp, and then I had a tune revision for the location of my air intake temp (which is on the back of the supercharger instead at the MAF sensor) that Improved the hp, 0-60mph times improved from 4.30's secs to 3.90's, aeroforce gauge showed abt 35 ponies more at similar temps (505 to 540). Have not dynoed this tune.

There is no leak from the headers as far as I can tell.

I think I am taking it to a shop on Monday. Any recommendations for Houston area (particularly north Houston). Potential of forging internals distinct possibility (if In deed I through a rod or piston or valve) so a shop that would be able to do this with proven track record is preferred.

Your thoughts/advise appreciated.

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BruceH · 10-25-2009, 10:52 AM

Ever thought it might be the supercharger? If I was in your shoes I'd take the belt off and start it up, if the noise was gone then it's the supercharger.

vasman · 10-25-2009, 11:09 AM

Quote:

Originally Posted by BruceH

Ever thought it might be the supercharger? If I was in your shoes I'd take the belt off and start it up, if the noise was gone then it's the supercharger.

Bruce, thanks for the suggestion. I do not think it is the charger.

a/ The metalic/whisting sound is not continuous. It sounds like a diesel truck when cold and like a bicycle with a playing card rattling on the spokes when warm under load.
b/ The sound comes from the driver side rear valve cover of the engine as far as I can tell.

The charger is in the middle of the car and the metallic sound should be heard equally from both sides.

The sounds matches 100% the rhythm of the engine. (charger is not moving the same rpm as the engine)

hammeron · 10-25-2009, 11:10 AM

if you rule out the s/c like bruce suggests,
then i think these other possibilities become
more distinct.

Quote:

Originally Posted by vasman

I am thinking valve, piston rod,?

BruceH · 10-25-2009, 11:17 AM

Quote:

Originally Posted by vasman

Bruce, thanks for the suggestion. I do not think it is the charger.

a/ The metalic/whisting sound is not continuous. It sounds like a diesel truck when cold and like a bicycle with a playing card rattling on the spokes when warm under load.
b/ The sound comes from the driver side rear valve cover of the engine as far as I can tell.

The charger is in the middle of the car and the metallic sound should be heard equally from both sides.

The sounds matches 100% the rhythm of the engine. (charger is not moving the same rpm as the engine)

IIRC that sounds alot like one eyed willie's car when he bent a rod, same location too. Might want to do a search, he had a video with sound.

Bruce

vasman · 10-25-2009, 11:19 AM

Quote:

Originally Posted by hammeron

if you rule out the s/c like bruce suggests,
then i think these other possibilities become
more distinct.

I fear that this is the case. The only think that puzzles me is when the sound becomes canary like which indicates a leak somewhere.

Is it safe to run the car (with the sc belt disconnected) without the charger turning?

vasman · 10-25-2009, 12:03 PM

Here is when I first start the car

http://www.youtube.com/watch?v=11nV3Nw0dZQ

and here when driving

http://www.youtube.com/watch?v=hvAdl3NvGEE

hammeron · 10-25-2009, 12:23 PM

if it's just for idling, i personally would do
it for troubleshooting, i don't think it would
hurt anything.

i watched the vids.....i'm no mechanic but maybe
a spun bearing or a warped rod seem to be
possibilities. best not to drive the car anymore,
because if it is something internal, more damage
can be done and more damage may = more $, to
fix.

Quote:

Originally Posted by vasman

Is it safe to run the car (with the sc belt disconnected) without the charger turning?

BruceH · 10-25-2009, 01:11 PM

Here's the thread I was referring to:

http://mustangforums.com/forum/4-6l-...g-problem.html

vasman · 10-25-2009, 07:03 PM

Quote:

Originally Posted by BruceH

Here's the thread I was referring to:

http://mustangforums.com/forum/4-6l-...g-problem.html

They do not sound exactly the same. They have similarities but not the same...
There is a whistle on mine that is not on his. I guess, I have to start taking things apart..