4.6l spark knock or?

[MJohnson]

Ok so I have a 1998 4.6 l xlt with 300,000 plus miles. New to me after 250,000... So no Idea about the minutes before I got it .But you're recently it's developed a ticking sound in the upper end driver side almost sounds like marbles rattling around in it. It dose it when you accelerate if you let off the gas it goes away alittle but then Comes back I've tried running higher octane fuel....Does no good,It goes away after I get above 70 and at cruising speed..... It also started surging under acceleration thought it was the transmission slipping but tack doesn't move. I don't even know where to start .. Change plugs wires new spark plugs.. no vaccum leaks that i can find so any help would be appericated...

 

[ChrisOIFdoc]

Sounds like it could be slack in the timing chain. May need to change the guides, tensioners, etc...

 

[Flexpedition]

^^ agreed with above, would add oil pump on the way out to the mix. 5w20 and Motorcraft filters?

 

[MJohnson]

So the timing chain would give the surging on acceleration but the go away at cruzing speed wouldnt the kilcking sound be all the time

 

[docraymund]

Noise like that would be valvetrain noise due to worn parts.

 

[skunkbutt]

I have the ticking noise in mine as well. I overheated it with only 102,000 miles on it. I agree its warn parts. The probvlem is finding which parts it is. What I did was pulled the oil pan to see if anything was in there like tensioner parts. was lean with no debris. next I tried heaver oil to see if ticking went away. nope, so this tells me it wasnt the oil pump or lack of oil at the top end. Next i pulled valve covers to see if any parts laying in head. clean again so this tells me i have warn parts. Its a ***** doing this work as its stuffed under the firewall. My solution is Im going to find another motor and swap it.
good luck

 

[Shabadoo]

Hard to say without hearing it and I know you mentioned it was in the upper end drivers side but it might be worth checking for exhaust leaks. Exhaust leaks can make a similar ticking noise. Just my $0.02