What is all the noise

[pdxgeo]

Drove Split Pea home from my shop today, 41 degrees, feels lower due to fog and dampness. Sat in traffic for quite a while but when it opened up i drove like fiats like, high revvin thru the gears. car reached normal operating temp which for it is high, usually reads low. Anyhow when i turned it off there was a cacophony of ticking, clicking sounds emanating from the general vicinity of the carb/intake manifold. ive heard a mild ticking during 'cool down' before but this was loud. Should I be concerned?

thanks all

George

 

[zonker]

naw - it's just the exhaust system cooling down. The greater the temp differential between ambient air and the manifold, the more noticible the sound.

Also, the quality of the exhaust pipe will make a difference there too. Thin aluminized steel with tick a lot more than a thicker stainless steel

 

[Jeff Stich]

Don't worry...

+1 on what Zonker said.

Add the (relatively thin) metal exhaust manifold heat shield into the mix of contributors, as well. My 128's exhaust does that all the time when I get home at night (mid-30º's F) or when I head up to Mammoth or June Mtn. to visit friends or go skiing. After the first minute or so, it's a very steady/rhythmic tic-tic-tic sound on mine.

As a precaution, you might check your spark plugs for a lean mixture issue on a particular cylinder, which might heat up 1 exhaust runner more than normal if you have a 4-1 or 4-2-1 steel header. :2c: