sarubin7

I have a 1993 gt 302 cobra intake with 74,000 miles. It has been running great for 10 years since I have had it. It just started to have a tapping sound from piston #1.I wonder if it is slop in the hardware, when I rev it I don't hear it only at idle. Is a bad idea to drive with it like this. I have tried special additives to see if it would help, no luck

Does it pay to rebuild the engine or go with a new ford 302 crate?

Riceinator

What kind of noise is it? Does it sound like a valvetrain noise? Try and get a video and post it up here.

mjr46

I just worked on a bronco 5.0 with such except on number 5 it was doing such, so I pulled the valve cover to check rocker arm play = was none visible, so then I pulled the plug....voula....electrode was burnt and grounding out and compression was 70 psi dry 95 wet, and a leak down showed an issue with 85 % leakage on that cylinder and air hissing in intake= intake valve issue, I've yet to pull heads off ,but I'm expecting to find a valve guide issue or valve issue, so follow the steps I used to locate problem and most likely you will to, you may have a faulty lifter bleeding off pressure too.

j-wigg

i've got my number 4 tapping/hitting. just noticed about 2 weeks ago. hoping something with the rockers or valves on the heads. just got gt40p's that are going in sometime soon. but plan on checking the roller when changing the intake sometime this week. hope its not bottom end. thats not something i'm not looking forward to for a few years.

FordMustangXBA

Have you eliminated an exhaust gasket leak as the cause? Sometimes it can be hard to distinguish the source.

j-wigg

i'll have to check it out. maybe this week sometime

j-wigg

so far so good for about 20 miles after changing the exhaust gasket. thanks

mjr46

so all it was , was and exhaust leak....good

j-wigg

your telling me good. i thought i had a serious bottom end issue with that. thought of the possibilities of the rockers, but whenever i heard a tap like that i always thought it was a piston banging. easiest 9.99 i've spent to clear that up

mjr46

ahhhh, just need to train your ear as to what an exhaust/header leak sounds like, 2 sec under the hood and I could of known it wasn't a rod knock or upper engine rattle