30 second rattle, carbon chunk ?

[blazer2007]

1980 2 wheel short box,stock 350/350. Rebuilt about 6 yrs. ago,only driven in the summer about 4-5 months of the year. Hardly ever on the hi-way which could give me carbon build up,mostly 30 mph.Small town of 60,000 pop. Anyway was driving home and suddenly heard a rattle ticking noise,a noise that you know is not good or normal,pulled over gave it a little rev. and the noise went away. All good for the ride home.Took valve covers of and nice and clean,nothing missing on the valve train. I never did get around to putting the inspection cover back on, wondering about that,will inspect that but was thinking that would make a different sound. What do think,have you had something like this happen to you.

[Matt Man]

Flex plate or torque converter? Mine had a knock while in gear, turned out the flex plate cracked.

[Dead Parrot]

If it sits for a long time, possible there is some water condensation in the gas tank. Especially if it was put up for the winter less then full.

If it still has the stock air cleaner & exhaust heater pipe, those can rattle if they get loose.

Could be one of the accessories developing a bad bearing.

Wasp nest or similar falling into the fan or torque converter/flex plate area.

[geezer#99]

Likely a piece of carbon. Stuck in the lifter and flushed out when you reved it.
I had a 230 did that once in awhile. Shut it off, let lifters bleed down for a few seconds, fire it up. No noise.

[blazer2007]

Thanks,I leaning towards the carbon theory, been a couple days now and nothing except a little high anxiety when driving it. I think I will dig up the flex plate cover and put it on just in case something did get caught in there

[Ziegelsteinfaust]

It is a good thing to get the engine on the highway for a good drive everyone in a while, and punch it to above 4000 rpm. Especially when the engine is hot.

Often times referred to as the Italian or Tony tune. Alot of Italian sports cars used or were known for using multiple carbs. So if 1 barrel which feed exactly 1 cylinder had issues. God forbid 2 full cyinders, or half the engine. Major driving issues would show up front, and center.

It really cleans up the internals, and gets it moving in a way that a slow crawl to the 7-11 never will.

Also draining your oil hot helps get more garbage out of the engine.

Another trick with a carb once warm. Is to take the air cleaner off, bring the rpm up to about 3500, and cover the carb with you hand. The vacuum of the engine draws in alot more fuel for a couple seconds, and pretty efficiently draws the garbage out if the carb. On some carbs I never had to readjust them because it so well. Just used a sand blaster on the plugs every 10000 miles or so as needed, and gapped them till they wore out. Alot of the luck was due to how well the carb matched the engine air flow wise, and the carbs quality.

[blazer2007]

I do try and go for a blast on the hiway now and then but this year is alittle different. I have heard of the Italian tune up,work,s on my old jeep