This is my second '03 4.0 and both have done this, this one currently has about 61,500 miles on it, first one had about 35K miles when I traded it in. Its the notorious can full of marbles for a second after cold startup. The engine was manufactured on 4/31/03 according to the sticker on the valve cover. Fortunately, it is quiet all the time besides immediately after a cold start up, like after sitting all night. Just kinda annoying to start it up around people after its been sitting with that diesel/rattle sound for a second until the oil gets to the timing chains. I've never actually heard one with the 2400-3000 rpm rattle before and this one does NOT do that. It doesn't get driven very much and I've read all the posts and such on here about having to pull the engine to fix it, at least the rear chain components. One of neighbors is an ASE mechanic and has access to the alignment tools to do it and has done a few of them...real pain in the butt. Question is...do I make it a winter project with his weekend help or just let it go...??

Oh, and I know someone will ask...it has a Motorcraft filter and Mobil 1 5w-30 in it...

I'd hate to go trading it in on a year or two newer one since this one is in spectacular shape and was Line-X'ed not long ago plus new tires, shocks, brakes, all new tune up parts and fluids throughout, etc....

 

The timing chain problem were resolved half way through 02. The 4.0 is a notoriously noisy engine on start up, even if you replace the chains and what not the "problem" will probably persist. Being chain timed the chains are just gonna make noise, most chain timed engines do. If the rattle is not continuous as you drive and never gets any worse don't fret about it.

 

what he said^ my 03 with 71k is a little noisy on a cold start...but it goes away after a second when the engine builds oil pressure

 

same with mine.

 

Same here. Just don't worry about it IMO.

 

i can only imagine how noisy its gonna be when i start it when i get home from the beach in 2 weeks lol

 

Ok...I wont sweat it for now...actually makes me feel better to know that you all have the same startup noise and it's no big deal. Have any of you tried using 0w-30 synthetic so it gets to the chains quicker on startup? I have always been kinda scared of trying that since its so thin when cold.

 

nope id stick with 5-30...the 0-30 might even make the noise worse because its thinner

 

since you made this thread, ive started paying attention to the noise on cold startups. saturday on cold start up, i was parked on a slight incline with the nose facing downhill, and it made the noise. But this morning, I didnt back in so the nose was facing uphill and it didnt make the noise.

also, i have to add that I parked my truck friday night at around 8:30, and didnt start it again till saturday afternoon at around 2ish. I came home last last night (2am) and went to autozone at 10am. so maybe its because It sat longer the first night. i dunno lol

 

Mine usually sits in the garage (flat). Seems to do it after a 12 hr+ sit. Of course we usually only drive it on the weekends, sometimes it'll sit for a week and a half or more between starts so it's understandable that it doesn't have oil to everything immediately.

 

yea i drive mine everyday so it doesnt rattle on every cold start...but if i let it sit for a couple days or more itll rattle a bit

 

There is some Lucas oil treatment stuff you can put in on your next oil change... replace one quart of oil with one quart of this lucas stuff... it's supposed to basically make your oil sticky so it stays in the upper parts of your engine longer, reducing dry starts. I'll see if I can find a link for ya. I've never tried it, but I don't see why it would hurt to try it.

 

My 03 did that a lot. It never hurt it. I ran the crap out of that engine too. I wouldnt worry about it. You should hear my 5.4 fire up... WOW its way louder than any 4.0L i have heard on start up. Its just common with ford engines.

 

zach, does your new dd have a bit of timing chain noise on start up? also, have you seen the goofy water pump setup on it yet LOL

 

I never noticed a noise, but maybe I'm not listening for it.