Lower Left Engine Noise

[higherlogic]

I just picked up a 1998 Ford Explorer XLT (4.0 SOHC) with 104k miles on it, and am noticing this knocking/rattling noise from what sounds like the bottom area of the engine on the passenger side.

The noise isn't constant, it comes and goes when idling, but right after you rev the engine it's the loudest. Here's a video of the sound, hope the quality is good enough:

http://www.youtube.com/watch?v=Xgu84s9GMnk

Any thoughts on this?

 

[Stinger357]

I have a similar rattling noise coming from the exact area when driving only. I have a 97 eddie 4.0 SOHC. 136K on it. It seems to happen at random times like maybe a lifter going bad? But it doesnt matter if I give it gas or not when it Happens. It only last a sgort time then it goes away, but then driving along it rears its ugly head again. It;s more of a rattling/flapping sound for mine. Any ideas?

 

[2000StreetRod]

cat heat shields

Check the heat shields on the catalytic converters. The welds break after a while and cause a rattle.

 

[higherlogic]

That sounds about right. The noise is loudest from there. Here's another video:

http://www.youtube.com/watch?v=8zu6ir79LmE

 

[G-96XLT]

Grab a pair of gloves and feel around until you can muffle this sound. I had this once and I fixed it with a cheap clamp.

 

[2000StreetRod]

What about topside?

The noise in the second video seems louder and more regular than in the first video. It could possibly be timing chain rattle. How loud is it next to the blower motor at the firewall?

 

[janolsson]

You could have this

Which is resulting in the bits bouncing around and the chain being slack resulting in this

If its not the metal part of the guide bust its almost certainly the plastic part
the photo below shows a new cassette and you can see the plastic part.

 

[higherlogic]

I put my hands around the heat shield real tight and it didn't seem to muffle anything. I'll get under there by the blower to see if it's louder though.

 

[higherlogic]

Really hard to tell if it's louder by the blower. It's definitely louder by the cat converter. Cold engine and idling is when it's loudest, only here it occasionally when driving, and after it's warm you don't hear it as much. I'll go get some clamps to see if that fixes the sound.

 

[higherlogic]

Ok, I was able to get under the car better today with some sun out as well. With the engine off, I knocked on the cat converter / heat shield, and sure enough, it rattles; so that's definitely the problem.

Thankfully it's not the timing chain, because I sure as hell can't take the engine out to fix that.

Another thankful note, the cat converter can be replaced (soaked the bolts overnight), so I'll just put a new one in along with some new sensors since I'm experiencing some power loss as well and have a check engine light.

Once that's fixed, just gotta put new ABS sensors in to get rid of that and put a clockspring in to get rid of the airbag light (code 32).

Thanks again guys, much, much, much appreciated