Hi Everyone, new poster here.
I have a 1998 V8 AWD Explorer (original owner) with about 95K miles on it. Maintenance has been regularly performed, but it hasn't been pampered.

Unfortunately for the past year or so the engine sounds like a sewing machine when it is cold, especially when accelerating.

If the temperature outside is warm (above 72F/22C or so), the sound goes away fairly soon once the engine warms up.
However, when it's really cold in the winter, the sound almost never stops even once the engine is fully warmed up.

A guy at a local parts shop said "sounds like a lifter has gone, common on these engines, nothing you can do".

Is that true? Is driving it in it's current shape (aside from sounding very bad) harming the engine?

What would you do?

Thanks!

PS
This was also posted to the small block v8 forum, but I'm not sure if that was appropriate.

 

Cracked header..........Very common on these vehicles.

 

Also, want to check for a cracked EGR tube.

 

I had an escort that sounded like that. I put a can of sea foam in the oil and it went away.

 

1/3 in the intake 1/3 in the oil and the rest in the gas tank. Worth a try! if it fixes ur problems then its worth the few bucks! If your unsure of how to go about doing this there are plenty of reference videos on youtube!

 

true.
if you have theses ear scopes you know? like doctors use but with a pipe @ the end

but anyway if u dont have thosse.
start the engine @ morning best w/ a helper so u can as soon as posible before it heats up touch EGR pipe line, exhaust heathers, & heather spaces see if theres any gas leak
cuz if its a sound like a motor cross or any 2 cycle engine could be exhaust failure.
Auto pars sell bandages for this types of issues

could be worn lifters or lack of oil
if you think it is in the internal of the engine, thanks to what they call dry start, get ur self a FRAM duble by-pass valve oil filter, keeps oil ducts always full of oil so even though u leave the car for a long period of time off it will lubricate really fast the head-block if still get some lucas oil stabilizer

 

u could also try using a long screwdriver may assist in pinpointing where the vibration/noise is coming from.. a nice long piece of hose also works for possible vacuum leaks.. just figured i'de throw that out there! a little southern ingenuity goes a long way!