I used the Lucas Synthetic HD oil additive and the TB-Zinc Pluc break in Additive...

I use that because I have a flat tappet cam (non-roller)

 

You use both at the same time? Do you substitute the additive for the same amount of oil? I notice on the break in additive, it says to add the whole bottle to your normal amount of oil. So reading that I take it that you add it to your entire normal amount of oil? I mean its 16oz, so only 1/2qt.. but you dont want to overfill your crankcase, but thats what it says to do. How exactly did/do you use it in your engine? Trying to duplicate what you did and see if it helps me at all. Maybe nothing will help me, but willing to try. If there is a way to plumb in a check valve, or accumulator I would be interested in doing SOMETHING.
I tell ya, once it warms up to operating temp, or close to it, it is quiet as could be, not a slight knock, ping, tap or anything from that engine, but upon cold startup that knock just annoys the hell out of me. Probably just have to get used to it... just wish I could do something.

 

One more thought has passed through my mind.. As stated before, this truck has 260,000 miles, have always kept the oil changed etc..
Could this knock that I am having upon startup.. which goes away after the truck gets warmed up, not immediately, but after getting close to operating temperature, would there be any way this could be the timing chain? Never been replaced... have been thinking about it, havent done it. Any chance of a worn/loose timing chain causing this knocking? It does seem that it is coming from the oil pan area though, but thought I would throw this into the mix.

 

Could be time for a refresh..?

 

Refresh? Whatchya mean?

 

I mean you have high mileage. You could have a worn out motor

 

WAIT... I missed something here....


you mean it knocks more than a few seconds? it knocks until it gets warm? like for a few minutes...?

if it knocks from the time its cold until it gets warm I'd say you got an issue...

I was thinking you mean it knocked but went right away after it started....

If thats the case I would Strongly think about pulling the pan and see whats going on...

you can check timing chain stretch very easy... the factory limit is 8° of stretch...it is possible that is making your noise and it is also possible the oil pan gasket split and has sucked into the pick up tube...

any difference in oil pressure?

could be a spun bearing (not likely) but if you had a torque wrench you could pull all the caps and inspect them...although if you find a bad one you cant just replace the bearing if you can feel ridges on the crank with a finger nail....

honestly man with that many miles on the truck you might consider a rebuild...unless you feel confident in the engine... my 88 GM has 290,000 on it and has never been apart aside from me pulling the valve cover to look to see if it was dirty... which its not but it did start smoking on the passenger side bank when it gets hot from me beating it too hard...still very strong and darn quick so until it breaks I aint fixing that... plus the 24mpg is hard to beat

 

Yes, it takes until it warms up to go away. When cold, if Irev to say 1500 the knock seems to go away. Only s
at idle does it seem to knock. Once warm, it is quiet as could be. Uses no oil, doesnt smoke or anything, just that cold start knock until it warms up, then no noise at all. Engine has never been open except the pan was replaced 2 years ago. Truck has never been beat on. The knock isn't real loud, pressure is there, but factory gauge so dont know pressure for certain. I didn't do the pan...how hard is it to get that off? Have to lift the engine dont you?

 

can you get a mechanical gauge to see what the actual pressure is?

 

Wouldn't I be leaking oil if the gasket split? How likely could it be timing chain? How do you check that?