Hey all I have a 2004 ford explorer xlt with 450 miles on it. I was adding windshield washer fluid to the vehicle with the engine running when i noticed that the engine sounded like a diesel or in other words had a constant light rattling noise. The noise isnt very loud and is only noticeable when the hood is open. It's coming from the black cover that has "4.0 L SOHC" stamped on it so Im assuming that it is coming from the engine itself. When Im driving the engine acts fine and is smooth and powerful. Can any of you 04' owners tell me what your 4.0 L SOHC sounds like when its idling in Park (With the hood open of course)?

 

Well did anyone check and see if their 04' was making noise?

 

Well I have an 02 sohc and it makes noises when it runs, as all engines do. If you are worried about it take it to the dealer,and have it checked. You may also use a stick or stephocope to listen to parts of the engine to see it you can locate the noise. (be careful !) you say the noise is comming from the sohc plastic cover, it may be the IAT (Idle control valve) is rattling, it is located there. Try increasing the speed of the engine to see if the noise goes away. If it does the IAC is taken out of the loop and that may be a clue.
It is hard to describe the sounds a normal engine makes.
Dave

 

I'm willing to bet that it's the same "diesel rattle" that everyone is worried about. The infamous cam chain assembly guides. I hope the noise mine makes caused by a faulty Idle Control Valve or something less serious.

 

Yea Im hoping that since its coming from the black engine cover with the 4.0 L SOHC name stamped in it, that its the IAC. I really hope that Ford didnt drop in a bunch of defective engines into the 2004 explorer. I have talked to 2002 and 2003 owners and they dont have the noise but all the 2004 explorer owners i have talked to, have the noise.

 

Does this noise occur at 2000 to 3000 rpm's? If so, it is probably the timing chain tensioner or guides. All 4.0 engines seem to develop this "rattle" at sometime. It is something Ford should fix once and for all! Good luck.

 

Mine makes it. 04 sohc. It sounds like lifter noise.
The sound is even and smooth, no tap,tap.
Sounds ok to me but Ive only had the car for two days.
What do I know?

 

This rattle coming from your intake are your inner air flaps. On the opposite side to your throttle body youll find a vacum line near the valve cover if you disconect it and the rattle stops. It indicated the selinoid the line is connected to is non working

 

I recently turned on my explorer to find a knock ive read and read. I already checked the timing chains and they are perfect. My transmission isnt out all gears work. The problem is that I step on the peddle but my truck wont accelerate past 5 mph. The knock is loud as hell. Any ideas if its the torque converter or pistons? I checked compression on all 6 and it seemed strong. The knock is on the driver side but when I got under it ir seemed to be in the back of the block near the transmission. I appritiate it in advance

 

A knock like that means you must take the engine and trans apart and find the source. Rod, broken piston, broken flex plate--all require removal of the engine or transmission or both to repair.

 

Thank you. Would the flex plate cause no acceleration? I took driver side head off and oil pan everything looks OK. My guess is the torque converter. But would the tourque converter sensor clutch cause a ticking knock noise?

 

Can you disconnect the tc lockup mechanism? Or is it all internal?

Seems if you disconnected all electrical connections, the trans would go into a limp mode where you would only get 2nd gear. Maybe. If it is the lockup, that noise should stop and it should go faster than 5 mph.

Grasping at straws here.