I have a 00 f150 5.4L V8. i just hit 90000. Over the last 2000 miles a weird noise has occured. When I start the truck it makes a noise coming from the front passenger side of the engine bay. it goes away after about 1 minute or until i drive off an reach about 2000 RPM. you dont hear it while driving just when the trucks been sitting and I go to start it. the noise it makes kind of souds like a diesel truck.. I went to 3 exhaust shops and got 3 different answers from them. 1 said it was manifold gasket, 1 said it was the cat, and the other said it was a lifter.. Im running out of ideas of how to pinpoint this noise...anybody run into this problem or have any encite as to what to do?

 

Does it make a ticking noise when the engine is first started, IE cold... then go away once it warms up? Also presents itself a smidge when you gun it? If so, check your two studs that are between the manifold and the H pipe. I bet they are rusted through and the pipe separated.

 

r u talking about the flange between the cat and the manifold??

 

Take a peice of 5/8 or 3/4 heater hose and listen for the noise. This will help to pin point down exactly where it is. I think you know what I mean, your ear at one end and search for the noise with the other.

 

Yea

 

HAHA! A lifter tick shouldn't sound anything like a diesel! I would take Good old Bill's advice. He seems to be a pretty smart guy.

 

My truck was making a noise similar to what you are describing, took it to a friend who used to work in an Ford dealership and he said it may be the timingchain tensioner. I know the truck had a cheapo oil filter on it when I got it so it probably had the wrong weight oil, he told me after I changed the oil to M/C 5w20 and put anM/C filter on it if it still has theis ticking sound to drain about a quart of oil out and put in some LUCAS, I did this and a week later the noise has stopped completely. This is just what I have experienced and what I did that fixed it. Hope this helps.

 

when i took it to the last exhaust shop the took a stethascope to the whole exhaust and pinpointed it to the manifold. they said it was the gasket. but im beggining to think it might be the stud breaking loose in combination with the oil/filter im running. ima change the oil with m/c oil filter and 5 qrts of m/c oil with 1 qrt lucas to c if it does anything.