99 Expedition 5.4 rattle sound???

[big_trucks_gavin]

I have a 99 expedition with 134k on it now. It has recently started to make a wierd rattle noise in the engine. It only happens between 2000-2500 revs the rest of the time its fine. Its not a loud grating noise, but a lighter rattle sound. Can anyone help, or have experienced this before?? Would it be something to do with the timing chains???? I try to keep the revs below 2000, but on the freeway thats hard to do ! im kinda scared incase its something majorly wrong, any help or advice would be much appreciated... Many thanks...Gavin

[Fordaddict]

I have a F150 with 115,000mi, the motor has always had a bit of rattle. The 1st engine was replaced at 36,000. I heard a knock in the bottom end the day I bought it so when the 36K came up, I told them "fix it or keep it". I think the 5.4 is a noisy engine. Try running some straight 30wt oil. I had a loose 302ci that I ran 30wt then 40wt then 50wt and two cans of STP. That all made the engine nice and quiet. I ran that Mustang hard all the time and it never blew up. The hevey oil will help the cushon the worn parts inside. Good luck milking those extra miles..

[yoop33]

Maybe try some 93 grade fuel for a tank and see if that helps. Sometimes it needs a good clean kicking.

[LxMan1]

Don't run straight 30W oil in these OHC engines. You need the 5W to get oil up to the heads/cams on cold start-ups!!!!
Does it do it under load or just reving to that rpm in park? Could be a cat conveter coming apart inside or a heat shield with a broken weld.

[Modified 99]

Probe around with a stethoscope or use a long screw driver to your ear (handle end). I had a bad guide on the right bank a while ago that was hard to find, replaced the serpentine belt idler first, then the chain guide. Noise is gone.

[Fordaddict]

Good point LXMAN1, I don't have the cold climate and the oil still flows in the winter! How about 10-30wt in place of 20-30wt? His motor must be getting loose assuming all the external type of rattles have been checked. My company has a 4.6L 97' F150 that has 500,000mi on the clock and it's run 10-30wt for years. We have two 5.4L's that both have about 150,000mi and they both have had internal rattles since new. My 04' F150 5.4L has 115,000mi and runs 10-30wt synthetic; it sounds the same as it always has... a little rattle..y

[LxMan1]

The cold internal rattles are probably piston slap. Thicker oil won't cure this. It is just from short skirted pistons and doesn't hurt a thing. With that mileage, I would run 5w30 myself, but 10w30 will work too. I wouldn't go any thicker though.

[big_trucks_gavin]

Thanks for the replys, I am thinking that maybe "modified 99" Has it, is sounds like a rattle in the chain, when listening to the engine it sounds like the front passenger side of the engine that has the rattle. How hard is it to change out the chains and guides??

[67blueford]

it might sound dumb but does it do this when its in cruise and your foot is off the pedal ... my 2000 f-150 made a rattle and it was the gas pedal ... its light and plastic and has no tension on it I would check this out before I spent any money on it

[big_trucks_gavin]

No, not the gas pedal. Definitly from the front top of the engine. Does it in park, or when driving, just has to be between 2000-2500 revs. Drives perfect and nice and quiet until it hits the revs above. !!!! And again perfect when reving above 2500. A wierd one !!!, thanks for the reply anyway !!!!