sup everyone, i got an early built 1980 F100 with the 4.9 my question is when it sits for about an hour or so the engine clatters extremely loud until its warm what is wrong with it or do i need to rebuild it. it has 75,550 original miles thanks for any help

 

Sounds like your lifters are chattering. When was the last time you changed the oil? Is the climate pretty cold where you live? May it is time to change oil viscosity. The lifters may also have sludge build up in them, if they are original, since oils from yesterday were not as advanced as today's oils. Older types of oil can and used to cause sludge and build up inside your engine, causing problems like you are describing.

 

Just changed the oil, it has had its entire life in south mississippi, running 10w30 using motorcraft engine oil at local dealer, hope this helps

 

If all lifters are clattering i would check oil pressure first!Then remove the valve cover and check lash

 

Did that to, i replaced the oil pump and screen, it shows normal all the time

 

It only clatters when the engine is cold, and this engine has never ran normal operating temps to it runs on C cold all the time sometimes goes to N on the word normal when its warm outside

 

Are you sure its valve lifter problem?

 

Sounds like lifter chatter to me. They seem to stick worse when cold. Some guys swear by Seafoam and use it to "clean out the engine." I tend to stay away from engine chemicals. If it were me I'd live with it.

 

is it ok to drive like that it, it has no power when its cold, or on regular gas i been running premium in it and it does alot better

 

If I told you it's okay to run an engine with an audible metal-on-metal noise, I'd be lying to you. It's not a good thing. But if you're already running thin oil and you're using a new filter and it's still chattering, there's not much else you can do unless you want to open up the motor. Maybe try a bottle of Lucas or STP.

I think you're getting a "placebo effect" with the premium gas. High octane fuel means it can be compressed farther before detonating than lower octane fuel. If you are running a stock engine and it doesn't have detonation problems, then upping the octane is wasted money because the added potential does not get used. If you actually put your truck on a dyno machine with 87 and 93 octane fuel, you would see very little or no difference at all. I'm saying that it's a common misconception that premium fuel makes you go faster. If you are under this misconception and you spend a lot of extra money to fill up with it, it's natural for the truck to "feel" faster. I assure you though it's not.

Anyone who wants to dispute my claim should show me documented facts and dyno charts comparing a stock engine vs. octane rating. Until someone can do that, "race gas" remains a misconception. And for people's future reference, "my grandpa always ran it that way, so you're wrong" does not count as scientific evidence.

 

oh ok, everytime i use regular it seems that it takes more effort for it to go, yeah its all factory

 

How long since a tuneup has been done? Has the carburetor ever been rebuilt?

 

i put a rebuilt carb on it and just tuned it up it has maybe 5000 miles on new plugs wires and distributor rotor

 

Cold running short trips certainly don't help. Try 5w-30 the next time you change oil using a Motorcraft, NAPA, or Wix filter. Check the thermostat for proper operation...should be a 195*. The Ford idiot guages produce less than definitive readings.

 

oil filter? anti drain back maybe? I s this alot of noise or just sound like single knock? Can you take a sound clip for us to hear?