So recently I've noticed that in the morning when I go to start my 390 (cold start), it fires right up BUT it makes a almost nocking type noise.... It goes duh duh duh ...... Duh duh duh ....... It has a few second pause in between but it also seems to stop once warmed up. Its almost a deep exhaust decible noise doesnt really sound like nocking on metal. I really hope it isn't a bad knock :/ anyone have any ideas?

 

Try adding some thick oil like lucas oil additive it will help keep upper parts lubricated when motor sits. good place to start.

 

Already ahead of ya. I have the Lucas stabalizer in there with my last oil change. Few weeks or maybe a month ago. Um I'm going to check my oil level to see if I needto add any. Should I put in a bottle of break in cam oil stuff from Lucas every oil change cuz I heard it has zinc in it or something like that Whig is good for flat tappet cams and I have a newer cam in it and don't wana ruin it ( I broke it in like 8 months ago).?

 

ok well it was low on oil but even after i put a quart or 2 in and drove it, its still there. I got under the truck and i cant tell if its from the engine or mufflers. To me i think its coming from the mufflers or the X pipe but its to damn loud to hear haha

 

If it goes away after warm up you might want to pull valve covers and check rocker arm to push rod clearance.

 

I just you tubed engine knocks to see what it would sound like and what I'm talking about sounds nothing like what was on you tube. Anyone have a video in particular that should sound like a knock in a 390?

 

Do you have catalytic converters on it? If so it could be a busted cat. Otherwise I'd go with valves. I had a strange knocking in my cherokee once. A month later I ended up with my rods and crank all over the road...

 

But the thing is I'm not so sure it's a knock. Cuz it seems to be coming from the flow through the exhaust and the engine doesn't seem to be making the noise. And I don't have cats either. Umm ima try to identify the source again when I get home.

 

pick up a cheap stethoscope on your way home. Start at the valve covers and work down then back. Might be loud as hell but its like finding a stud in a wall.

 

Dads a doctor so I already have a few and I think I can rule out a tick or engine knock cuz every you tube video I've watched is. Completely different then what I'm hearing. I think it has to do with my X pipe sobim 95% sure it's an exhaust sound from my new system..... I'll get the scope out and listen just in case though .

 

9 times out of 10 its a blown exhaust gasket or even an exhaust donut i betcha thats what it is since its very common with all fe's