Ok - I admit, I don't have a good description of what's going on, but it's not normal. When I accelerate slowly, or go up a hill, I'm hearing a "rattling" sort of noise that did not used to be there. I have heard it also when slowly decelerating.

I need to crawl under and look, but my big concern is I'm about to go on a 2000 mile trip with a small horse trailer. Could this be a festering major engine, transmission, or otherwise problem?

 

Could be a heat shield on the exhaust. Try and pull them with your finger. The welds break.

Could also be the inspection cover on the front of the transmission.

Those are the two "common" sources for rattles on the V10 Excursion.

 

What are the parts of the exhaust system? Right about where the transmission and transfer case are I have what looks like a muffler. But further back there is also something about the size of a muffler. The first one (nearest engine) is wrapped in a metal shell. Some small rocks were trapped in there. There is an 1/8" thick metal shield that sits below that; covering both the muffler (assuming that's what it is) and the transfer case. That shield is rubbing on the muffler and when I tug around on the exhaust line the rubbing noise is loud.

Some of the heat shield welds are also broken, but probably not enough to cause the noise I'm hearing.

That heavy metal shield almost looks like it's been bent slightly upward. If that is the case, that would be why it's rubbing on the muffler. I might be able to pry it off with a long bar. There is a exhaust line support hanger right above that metal shield, so I don't think the shield is suppose to support the exhaust line.

 

Does it do it only when the torque converter locks up?

Perry

 

How do I know when the TC locks?

 

It will unlock when you take your foot off the gas and then lock back up when you start to accelerate again. It is usually the last noise you here in the transmission when you are accelerating from a stop. Mine made a buzzing/honk noise when the TC would lock. The fluid was bad. Changing it made the noise go away. I also have a sheet metal noise that I am not too concerned with. Changing the fluid got rid of the honk.

I think it goes 1-2-3-OD-lock TC in the shift sequence. This is accelerating easy not romping on it. It only happens for a short period of time so if yours is constant it is not the same problem as I had.

Perry

 

Perry, thanks. I have a short drive today and will listen more carefully. Generally, the length of the "rattle" varies a bit. It seems to be worst on gradual acceleration or similar slow-down. That first large component of the exhaust system rubs directly on what looks to be some sort of shield/guard for the transfer case. That guard appears to be slightly bent up towards the floor and as such is in contact with that exhaust component (is that the muffler? or is the muffler the 2nd component nearer the tailpipe?).

I don't notice any sort of engine/transmission symptoms - like hesitation, etc. It's just this rattle noise. I doubt the few small gravel pieces I discovered could produce that much noise. But that rub I describe above certainly could.

Can I post pics here?

 

This sounds very similar to my issue. I have an '03 excursion with 97,000 miles. I have the V-10 engine, and it has been making this rattling/ chattering noise from what appears to be the forward part of the transmission, rear section of the engine. I do not suspect engine probs, but have thought it was an exhaust leak. I replaced the muffler, but the noise is still there. I examined the noise further and it occurs on acceleration, between 1700-2000 rpms, and does not occur during idle revving, neutral free roll, or during turning. there is also a groaning noise that seems to happen when the vehicle shifts into overdrive, at approximately the same rpms, but if I am excellerating at a faster rate, it does not occur. I do not believe it is a heat shield or exhaust issue due to the rpm nature of the noise. other than the groaning, there are no drivability issues. still searching for the culprit. any help would be appreciated! thanks in advance.