well ive had this noise for a while now and its starting to get to me. really only happens when the truck is cold, but its definitely coming from somewhere in the engine bay. almost sounds like something rattling when i start the truck up. i dont think it's the starter. i dont know how well a sound clip would be if i tried to get one, u would probably hear the exhaust more. might leave it overnight at my mechanic and have it start it up the next morning and see what it is. i dont even know how to explain it, but it a vibrating noise that rattles and sounds like something is loose.

 

Got the same thing ... I had a buddy at a shop said that it was the oil filter I was using and the oil wasn't making it thru the motor fast enough on a cold start... Well I went back to a motocraft oil filter and it solved the early morning tapping problem but I still got that same clacking sound in the lower end of the motor .. ( Could be bearings, or maybe flywheel ... I am just guessing ... Some people even have said could be a motor mount causing the engine to tilt on start up and causing the fan to hit the shroud.. HMM

 

i was thinkin about the fan hitting the shroud if the motor mount is loose. im getting my oiled changed and rear diff fluid flushed on monday so well take a look in there and see whats goin on. the noise isnt really consistent. the exhaust drains the noise most of the time..

 

Cat shields , -very common. If your under 80,000 miles - Ford WILL replace that cat FREE under the emissions warranty. EVRYBODY has this warranty.

Ford also has a TSB on it.

 

really? how do i go about that?

 

Head over to service, talk to the manager, -set up an appointment. Tell him you think your converters are noisy @ cold start.

The heat shields are only spot welded on, that's why they don't last. Ask if it's free to check them, - that I don't know..?

You might have to clamp the heat shields w/7" band clamps 2-3 of them. Wrap them right around the shield the best you can. Then start.

Uknow, If it happens @ cold start, you might be able to find the loose one yourself. Look for broken spot welds.

Good Luck.

 

thanks man! ill take the truck over to my mechanic tomorrow cuz i gotta my oil changed along with the diff fluid flushed and well take a look at it while its up on the lift. i dont wanna take it to ford before he looks at it, bc i know theyll pull some BS and say that they had to fix something else and charge me $100. ****ers!

 

the truck was on the lift today and we took a rubber mallet and the front left cat sounds hollow and the others sound solid. I'm not sure if its blown out, but that's definitely where the rattling is coming from when the truck is started from a cold start. im gonna go over to ford and tell them the deal, but what they do to fix the problem? no way in hell will they put a new cat on....

 

I also had that cold rattling noise. It ended up being some pebbles ( BB size) That worked themselves in between the heat shield of the catalytic converter and the converter. I fished them out using some of the wife's arts and craft wire and pulling back the heat shield some. Annoying rattles gone now!!

 

The cats are covered under a 8 year/80k mile emission warranty, 7/70 in California.