Cascade Crew

DBL_TKE · Posted: Mon Oct 07, 2013 12:43 pm Post subject: Squeeking from engine

So yesterday I noticed a pretty bad squeek develop after a 1-2nd launch and spinning at about 5500 RPM'S until I hit third. Once I came to the next light I heard a rhythmic squeek that begins at 3000 RPM'S and up. It's also way work on a rev when you let off the throttle all the way back down to idle. I honestly thought it was a belt so when I got home I lubed it up but the sound persisted. Listening around the engine bay it sounds like its coming from the rear of the engine on the passenger side. I'm thinking that it may be something in the valve train as its definitely most audible from up top rather than under the car. I'll be pulling the valve covers when I get off work to inspect for any damage. First thing I'm guessing is an issue with a lifter.

Twilightoptics · Posted: Mon Oct 07, 2013 2:53 pm Post subject:

Take your belts off and rev it up

If its still there my $ is on an exhaust leak.

DBL_TKE · Posted: Mon Oct 07, 2013 3:43 pm Post subject:

A squeak from an exhaust leak? I've heard leaks that sound like a tick, whistle, paper flapping in the wind but not a squeak yet. Though I did just fix a exhaust leak at my collectors yesterday but that didn't eliminate the squeak. I'll double check all my clamps and flange bolts though.

Twilightoptics · Posted: Mon Oct 07, 2013 3:52 pm Post subject:

Never heard valve train "squeek" either. I'm going more based on symptom than your interpretation of sound. An exhaust leak can cause a reed type sound that yes can sound like a squeek. More common on metal gaskets on lsx engines.

chevymad · Posted: Mon Oct 07, 2013 4:55 pm Post subject:

Possibly a rocker. They squeek pretty good when they're not oiling. The original motor in my 74 did that on its maiden voyage.

aaron_sK · Posted: Mon Oct 07, 2013 5:58 pm Post subject:

I had a distributor bearing take a dump on me one time and squeak like you describe.

As Paul said this is all hypothetical until you pull the belt and run it to eliminate any chance of accessory noise.

Twilightoptics · Posted: Mon Oct 07, 2013 6:28 pm Post subject:

I suppose a rocker can, or even a pushrod for that matter. But based on his description, those you should be able to hear and identify better at an idle, vs coming in at 3000rpm.

DBL_TKE · Posted: Tue Oct 08, 2013 5:52 am Post subject:

The noise is still there without the serpentine belt on. I also pulled the passenger valve cover and it really sounds like its coming from right there. I was unable to pinpoint it though. No visual indications of any abnormal wear either. It's almost non existent when the engine is cold but comes on as it warms up. You ever hear an engine that has a spun rod bearing? Same sound but without the actual knocking and it's virtually not audible from underneath.

fiveoformula · Posted: Tue Oct 08, 2013 9:14 am Post subject:

It is a really odd, consistant sound.. We thought at one point that it was the header on that side squeaking against the "frame" rail, but couldn't get it stop making the noise prying against the exhaust.
Its not loud but it is consistant when you rev the engine.