Hey everybody.... I was finally sick and tired of my 1998 GMC 4x4 breaking so I got a 1984 Ramcharger with a 318. For a second or two at cold start the engine has a rod or main bearing knock. After 2 seconds it goes away and doesn't come back until the truck sits over-nite. It idles smooth, doesn't smoke and has great throttle response. The truck supposedly has 126k miles and I was told that the motor only has 20k on it. It has been cosmetically restored and came with a plow so I didn't worry about the brief engine start-up noise. Are these engines known for start-up noise? I know they have steel cranks in them. If I do wind up changing the motor out is a swap to a 360 a better idea? Is a 360 a bolt in swap? This truck will see maybe 3k miles a year of use. The only plowing it will do is my driveway. I plan to keep it for many years and treat it right. Thanks in advance for any advice!

 

Hmm, I wouldn’t say that’s normal. Might be worth it to have a local mechanic check it out; could be as simple as replacing a bearing.

 

I can't say I have heard them make the sound either.

a 360 should be bolt in, but will use a different engine mount on the driver side.

If you still have smog/ electronics I believe they will work the same.

 

What weight of oil is in it? I would try changing the oil first. Also use a high quality filter.