79XD82ZJ

Sounds like it but not too sure exactly. When idling, you cant hear it, but once moving it starts to knock slowly, and increases with speed. Sounds like its coming from under the rocker covers or that area, and its close to the drivers end than the front. I assume its an exhaust valve loose or something, but before i get it checked out for sure, does anyone know if im correct, or could this be something else. Also, should i stop driving my car incase this could lead to bigger problems. Previous owner said something about fixing a valve problem with him. Would this be expensive to sort out? Any suggestions on better valves to use if needing replacement.

northiam

I'd say its more likely a collasped lifter or loose rocker.

brenx

If it's still running the factory samshaft and lifters. I dare say the cam and lifters will be trashed. Best one I've seen is the cam lobes had worn completely round. Yup, the camshaft was that old. The engine was a V5 cause 6 of the lobes were round.

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XB Fairmont (street car) 11.07@123.02mph.

79XD82ZJ

Thanks fellas, yeah things are pretty much stock in this engine(351cl),sounds like some work to do i guess. Wont be able to pull apart untill early next week. I hope its not as bad as it seems. Once sorted ill let yous know what happened. Just wondering if itll get me to work everyday untill then.

brenx

More than likely it will but it'll be rattley.

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XB Fairmont (street car) 11.07@123.02mph.

79XD82ZJ

Ive finally got the engine checked, and yes it was a lifter has droped, because of the camshaft lobes are trashed.Not to sure why this sort of thing happens (besides being to old) as my 302cl is sweet as and thats in a factory 79 XD.So at the moment im replacing the lifters, camshaft, and anything else that maybe ripped in there while its open.