NEED HELP diagnosing my issue - 04 Explorer

[hawksXC]

Here goes, hope someone can help I'm in a bad situation my mechanic is telling me one thing, and my mechanic cousin is telling me another. We can't seem to diagnose the problem.
2004 Ford Explorer, 137k highway miles kept in great shape regular maintenance. For the past year it has been making a rattling noise on start up (cold) which we were told were the bearings in the engine but that we would have some time before a complete breakdown. Once warmed up the truck has been great, and the sound goes away. Two weeks ago it began making a new sound on start up, a louder deep whining sound. Once again went away once warmed up. The next day it became a rattling noise almost like metal being dragged under the car, and when I was driving home it lost all acceleration and RPMs when in "drive". I couldn’t get it over 1000-1500 RPM or 10mph even pedal floored. However I can rev the engine in "neutral" and get an RPM response. No dash lights are on. It continues to start up easy just as before, but sounds like a metal noise clanking and rattling. The mechanic said he thought it was the left front Catalytic converter. However, my mechanic cousin is saying that it could be the whole engine, that the bearings have finally worn out. Would the car start easily, with no dash lights if it were the bearings? Suggestions? Thanks

 

[Fastest Caskets]

I was thinking catalytic converter. Alot of people with thos trucks notice a rattling noise on startup that is the timing chain guides which usualy goes away after it warms up. You would think the cats would throw a check engine light on... if the main bearings were completley wiped out the engine probably wouldnt even attempt to start, but thats not to say that they aren't on there way out. I have never seen your truck, and if you trust your mechanic, I would go with his advice. Some times our "cousins" mean well but don't always know everything.

 

[matt0248]

Which engine? It makes a big difference. If it is a v6 it is probably a timing chain related noise.

 

[hawksXC]

its a V6 engine. I agree if it was the CAT I would think I would get a service engine light or something for emissions failing, or running rough because of a misfire if the computer was sending the wrong signals to compromise. The rattle has been an on going noise, but the truck has always ran good once warmed up and the noise goes away. This new sound came on all of the sudden and the nxt day the truck was undrivable. It starts right up easy and can rev in neutral, not to full power but up to 5000 out of 7000 but in drive it can't accelerate above 1000 rpm. Also, I pulled all the spark plugs individually to see if I could get the noise to stop, but that didnt take care of it. The noise is only at idle, or whent he RPMS are decreasing. When accelerating it goes away.

 

[vipersinu2]

the sohc has timing chain problems, that loud rattle is the timing chain, your timing is probally out, it happend to me on my sohc at 121,000 miles, these sohc will run like crap even if it is one degree out, start looking for a new motor. any sohc motor will work.

 

[05explorer1974]

I agree with the above it sounds like bearings or it could be the cassettes they use. I know those a big problems. We also did replace 2 tensioners alot to. If you do have to replace the engine make it is a 2004 or newer. 2004 and up are Drive by Wire so 2003 and lower will not work. The throttle body is electronically controlled by the computer where the 2003 and lower are not. It also has to be a sohc out of an Explorer 4dr., can not be out of a Ranger or Sport trac. Sport Trac did not go to Drive by Wire until the remake 2006. (I think thats when the ranger went to).

 

[stoogefan]

To me, it sounds like you have a couple of unrelated problems.

I doubt it is the bearings. It’s not a common problem with this engine and it sounds like you have maintained it well. Anything is possible, but again I doubt it.

I doubt it is the timing chains. The cassette issue was addressed far before 2004 and the primary chain would begin to rattle around the 2200 to 2800 rpm range and it’s unlikely that either of them would go away when warmed up. Again it’s possible, but unlikely IMHO.

It’s hard to diagnose something without being there, but I’m thinking that you have unrelated problems.

For the rattle, I would check the catalytic converters and the torque converter. It’s possible that something else may be loose underneath too. If it’s one of the cats, you may be able to hit it with a bat or some other solid object when cold (not hard) and hear a rattle. You can also search this forum for “torque converter rattle”. A mechanic's stethoscope may also be useful.

For the whining sound, maybe take a look at your harmonic balancer, tensioner, belt and idler pulley. Definitely take a look at the sticky “4.0 Harmonic Balancer - know when it's going bad &how to fix”. This could also be things like the power steering pump, alternator, or transmission. Maybe try to isolate the sound if it can be reproduced.

As for the power loss when under load, I would look at the fuel system (fuel pump and filter) first. It could also be misfire, but that would generate codes pretty quickly. It sounds like the MIL is not on, but have you scanned it for any codes?

 

[vipersinu2]

I agree with the above it sounds like bearings or it could be the cassettes they use. I know those a big problems. We also did replace 2 tensioners alot to. If you do have to replace the engine make it is a 2004 or newer. 2004 and up are Drive by Wire so 2003 and lower will not work. The throttle body is electronically controlled by the computer where the 2003 and lower are not. It also has to be a sohc out of an Explorer 4dr., can not be out of a Ranger or Sport trac. Sport Trac did not go to Drive by Wire until the remake 2006. (I think thats when the ranger went to).

you can use any 4.0 sohc engine block, just transfer your intake and eletronics. I have a 2010 ranger engine in my 03 explorer and it works fine, and it is the same block that I put in my 97 explorer. rangers,mustangs,explores, all have the same 4.0 block

 

[vipersinu2]

if you want to know for sure, take off the intake and valve covers and look for play in the timing chain.