I just finished putting on my brand new Weber 32/36 DGEV carb. It fired right up and ran fabulously for about 20 minutes. Then I took it for a spin. Not long after I began putting the car through its paces, it hesitated a bit and started making this horrible CLATTERING sound.

 

I've had the oil pump mickey mouse seal sewing machine tick before, and this ain't it. It's LOUD. Plus, the car has newish (within the last 2-4 years): oil pump/oil pump seals, front and rear main seals, valve cover gaskets, clutch, . Oil pressure is still good, Throttle response is ok. It doesn't leak anything. Engine is noisy as heck.

 

My GUESS is that it's rod knock, that I lost one of my rod or main bearings, but I'm concerned about a small washer I lost that I have reason to believe MAY have fallen into the intake manifold (although I really doubt it, because I checked with a magnet and everything). The sound seems to be coming from the rear of the engine, and is slightly more pronounced on the drivers side.

 

Any ideas, amigos? (I'm really glad this happened now and not two days from now, when I was planning on being in the middle of Idaho).

 

AAARRRRGGHHHH!!!!!

Sounds like the timing might be off? If it's combusting the mixture before tdc it'll make alot of clattering. I hear Toyota Camrys making that noise all the time...

I'll be hanged if I didn't just thrash the heck out of it and the sound went away. I guess it was an oiling system problem? Car's been sitting for a coupla weeks without running.

 

Just drove it 100 mph on the freeway with no problem. Hmph.

When it doubt.... Drive it like you stole it!!!

check timing belt idlers

timing belt idlers are newish, too. i replaced them when i did the timing belts. the gauge showed adequate oil pressure, although who knows how accurate that thing is.

Just drove from Boulder, CO to Sacramento, CA in the 86 GL. There were two or three times when the engine started clattering for a few minutes. Sticky lifter?

i would drain the oil and run some atf through your system (just idling not under load) that will clean the gunk out of your oiling system. then replace oil and see if that helps. just a thought but worth a try

Washer/nut down the carb got me thinking about a 394 Olds engine I bought for $15 about 45 years ago. Bought it just to take it apart. The person I bought the engine from dropped a small nut down the carb. When I removed the cylinder heads, the damage was awesome. Every combustion chamber and the tops of every piston was hammered. How that nut moved among all the cylinders is still a mystery to me but somehow it did.