Hi,

I have a '99 Accord w/ 2.4 liter, and 5speed, 151k.

Lately, I've noticed fairly loud tappet-like noise, especially when the car is cold, but gone when the car is warmed up.

I listened carefully this morning with the hood up. Three times, a couple of minutes apart, each, I heard a loud clang, a single clear note, metal hitting (but not scraping) metal. WTF???! Any ideas?

Outside of these noises, the car seems to be running fine. No problem ona 450 mile trip last Saturday; it's peppy, gas mileage is down by maybe 2mpg, but that may be winter. Any info would be much appreciated!

David314

 

I would remove valve cover and inspect valve hardware comparing one cylinder against another, looking for something broken or missing. Excessive loose valve clearance, might cause a clang intermittently.

good luck

 

Something broken or missing-the car would not run fine.Loose valve clearance-MAYBE,as you mention when warm the tapping is not present...at 151k miles,you can expect a tapping at cold start up,as the oil is cold and thick.Dirty/gummed up lifters are more than likely the culprit.The oiling holes in them constrict,not allowing the thick/cold oil to flow through them.About 100 miles before your next oil change,you can try a can of Sea Foam,following the directions.I've heard many positive results.You could also try running a lighter w-rating oil.......

 

I use Mobil One 5-30.

The "clang" may be a bit of an exaggeration. More like a single nut hitting the valve cover. But the sound definitely sticks way out over the general clacking.

David314

 

Well Dave,w/151k on the clock,you can expect some ticking and other strange sounds as compared to a new engine or car w/less miles-especially w/winter here.I have a Mazda w/174k.and it ticks at cold start-up.It's got hydraulic lifter assemblies that are prone to ticking due to deposits within the oiling holes-restricting oil flow when cold.I'm just in no hurry to pull the whole top of the engine apart and all 4 camshafts in order to clean them.I think you'll be fine.Keep the oil changed,and maybe check out the Sea Foam treatment.Ol' timers use ATF.

 

You could also try a quart of Marvel Mystery Oil about 1000 Miles before your next oil change (instead of seafoam.) Some members swear by that stuff.