I left my 68 Chevelle (w/76 305) sitting in the driveway for about 6 months without starting it. For several years before that it was a daily driver that hadn't gone more than a week without some kind of driving.

I started it up and it began knocking really loud - my first thought was "oh crap, the oil leaked out!" but it's all there. On the second start it still knocked and I let it run for a minute thinking that it might fix itself and smooth out. It didn't.

What should I look for and what can I do? This isn't a great engine, with 250,000 miles on it and low horsepower but it is already in the car smile.gif

(I tried the search function without any useful results)

Lifter bleed down? :confused:

I would pull one spark plug wire at a time and see if the knock stops. If it does, you might have a problem. Mine stopped and It was rod bearings on 7 and 8 with a few broken rings. I hope your tests go better.

Before this I tried a bottle of Marvel to loosten stuff up and a few heat cycles, but mine never stopped.

Thanks for the replies; I just went out to start it and the battery is dead smile.gif So it's on the charger right now and I'll try the spark plug test tomorrow.

As far as I know, it should have hydraulic lifters. I'm not aware of any maintenance that they require - should I just let it run if the rods seem ok?

Thanks again! Fortunately this is not my daily driver so there is no rush...

I HAVE ALSO SEEN CARBON GET LOOSE AND CAUSE A LOT OF TOP END NOISE AND ALSO SOMETIMES THE
WIRST PINS GET DRY AND GAUL UP ON START UP, I
SEE THAT ON SOME ENGINES THAT SET FOR A WHILE.

CARL

Well yesterday I went with the fresh battery to start it and it didn't start. Preliminary diagnosis is that it doesn't have any spark since it didn't even pretend to catch after pouring gas into the carb. Bleh.

So it will be next weekend before I do anything to it - probably start with an oil change just to be safe.

Once I figure out what's going on I'll post an update, but seeing as how this isn't on my top 10 priority list, it may be a while.

Thanks again for the repiles...

It must have been lifter bleed down, because after I got it started up the knocking went away after a few minutes. Glad it wasn't something serious!

(...turns out that the fuel gauge was a little misleading last time, said I had a quarter tank when I didn't smile.gif )

Drop 8 oz's, a half bottle, of good old Marvel Mystery Oil in her the next time you change your oil! Like 500 miles or so just before to help clean some crud that may get into your lifters again out.. IMHO..

Just throw the other half of the bottle into your gas tank on a full tank to help lube/clean your valves too....

I say this b/c the darn "snake-oil" named stuff is VERY good "top oil"!!! I have used it periodically for years AND years in my cars...

pdq67