C4ProjectCar

I just dropped a new 383 into my '90, and I've found that a fairly loud ticking comes from the passenger side valve cover once it warms up. While driving with the windows down it sounds almost like air hissing, but once I stopped and popped the hood it sounded more like a ticking.

I think I have an exhaust leak because of exhaust popping at idle, which I thought could have caused this too, but this noise sounded far more mechanical with the hood up.

I'd have pulled the valve cover already but it's a pain to take off the passenger valve cover.

antfarmer2

Try tighting your exaust

JrRifleCoach

Try tightening your EXHAUST manifold bolts and the down pipe bolts as well.

tbirdsps

383 with stock covers and billet rocker arms will likely make contact with the cover. If you have stock rockers then not.

John A. Marker

Take a small rubber hose (3/8" or so) and use that as a stethoscope. With the engine running poke the one end around the exhaust manifold and listen to see if you can pin point the sound. You can also take off the oil filler cap and put the hose inside the valve cover and see if the sound is louder there. If so, then take off the valve covers and see if the rocker arm is hitting the VC. Most likely it would be an exhaust valve.

C4ProjectCar

I'll snug down the exhaust manifold bolts and see if that fixes the noise. If not I'll see if I can track it down with a hose. Thanks guys.

John,
What would be wrong with an exhaust valve to cause a noise like this? Just a bad seal so it leaks exhaust on the power stroke?

I have Edelbrock "low profile" covers which are about an inch taller than stock, if I remember correctly. They're in between stock and tall.

Cliff Harris

Do these valve covers have a vapor separator baffle in them like the stock ones do? There is not much clearance between the baffle and the rockers so a rocker might be hitting it.

C4ProjectCar

They do have a baffle. Thanks for the tip, I'll pull the cover and check it out.

I'm going on a backpacking trip tomorrow morning so I won't be able to do so until Monday, but I'll give an update as soon as I do.

C4ProjectCar

I just found out that my dad accidentally swapped wires #2 and #4 when he plugged them in. Before I pull the valve cover, since both affected cylinders are on the passenger side is there a chance that this could cause a noise like what I heard?

Edit: Yep. Swapped the wires and it doesn't make the noise, not to mention HO-LY CRAP does it drive better. That new engine is a beast.

Also (off topic) could driving it with these swapped have hurt the engine?

John A. Marker

Better send your Dad off on an errand to stay away from your car . No, I know he is a great help. Wires are easy to do if you get distracted.

As far as the exhaust valve(s). They are usually the highest lift and will hit the valve cover when you still have lots of clearance on the intake valves. I kept my stock covers on the ZZ4 and the cam lift with 1.6RR was .534" on the exhaust. I used a taller gasket, but ended up sanding off the top rear edge of the RR to clear the VC.

Sounds like your good here now. See what is going on with the timing.

-John

C4ProjectCar

Thanks John!