98 Navigator 5.4l 4x4 Rattling Noise

I am attaching a video of a rattling noise I'm having. It goes away when driving. It is really only noticeable at Idle. I rev it up a little in the video and it goes away.

I have noticed this noise for a few months now, but it is getting worse.

I have been under it to inspect and can't find any loose heat shields or anything. I also removed the inspection plate on the torque converter to make sure the flexplate bolts were tight and they were.

The noise really sounds like it's coming from the torque converter area.

Beast Noise - YouTube

I thought I would add. I just got back from an 800 mile trip where the alternator went out and stranded me. I have AAA but they couldn't come tow me until 3:00 AM but I found a local guy that took me to a local shop that fixed it quick and cheap. Even thought I had to sleep in the car overnight in their parking lot. If I had a battery charger I could have fixed it myself....

I also have another 1200 mile trip planned for 8/27 and 8/28 and really don't like being stranded.

Have the catalytic converters been replaced? Just from the description it sounds like a chunk of the material has broken inside the cat. That's the rattling noise you're hearing.

That's more of a knock than a rattle really... That is only to say it sounds more internal. Does it sound more like it's from the trans or the engine side? Sounds like a loose flywheel or torque converter honestly.

Cat's have not been replaced.

It sounds internal. It's either the rear of the engine or torque converter area. Though, you seem to be able to hear it better on the drivers side.

The ideas I could come up with online were. Dragging Starter gear, broken flexplate, bad torque converter(or going bad), loose heat shield, rattling cats.

I'm hoping someone can help me make the call. I'm going over to a friend with a lift this afternoon to see if I can hear better with more room to move around underneath.

Listen to the noise in this guy's video (jump to about 1:10 for noise) : Saved 5000 dollars. fixing my car. Broken flexplate - YouTube

Mine does not seem as loud as his....but I could be wrong. You can't hear it when driving and it seems to get worse when the engine is HOT.

Yours doesn't seem that loud, but it's also covered with the bell housing. I'm interested to hear what this ends up being!

I've heard bad cats before and they're a tinny clack sound, the camera makes it sound like a knock for you.

My money at this point is on loose/cracked flywheel/flexplate or torque converter...

Well I couldn't get it over to the lift last night. Had to go home early

This morning I raised it way up in the air with the forklift and put jack stands under the control arms so I had more clearance to maneuver.

Of course the noise is not happening right now. You can hear it a little when starting. It was terrible when I made the video above. I even went and bought a mechanics stethoscope but there is no noise to use it on...

I took a rubber hammer and hit the cat's on the drivers side and they rattle after hit. So I hit the passenger side and nothing....

So...I'm pretty sure it's cats on the drivers side rattling. I wish it was doing it so I could listen with the stethoscope. Because it sure sounded like it was coming from the torque converter area.

Hmmm, that's a weird sound for a cat to make, though I'd prefer it to be that lol! Hopefully you nail it down soon!

I took it to a muffler shop and they said it was definitely rattling from the drivers side rear cat.

He used his electronic thermometer and said all 4 cats were bad and I should replace them. Is this a LEGITIMATE way to test the cat's? By Tempature? Wouldn't a better way be to read the O2 sensor data?

He said they prefer to have people replace their muffler at the same time. Since, the pieces of the converter can end up in the muffler.

They wanted around $1050 to replace all the cats and the muffler. He quoted me $440 per side for the CAT parts.

By the way. I ordered the walker bolt in replacement from Summit. http://www.summitracing.com/parts/wlk-53273

I was going to order the Eastern Catalytic from Rock Auto but with shipping is cost more $254.79 + $35.12 = $289.91

In my search I also noticed I could get the Walker from Rock Auto for $274.79 + $19.98 shipping = $294.77 It was kind of interesting the shipping price difference made them about the same price.

Someone recommended I get the Walker.

Sounds like the muffler shop was up-selling. Yes it "can" get into the muffler. But for that price I could get a whole lot better exhaust than stock replacement. More than likely custom bent too! Good to hear you didn't go for their offer.

I was pretty sure when I went in there I wasn't using them....I had already searched out parts. But, I wanted an opinion, and if he had a reasonable price I probably would have used them.

jbanks said:

I was pretty sure when I went in there I wasn't using them....I had already searched out parts. But, I wanted an opinion, and if he had a reasonable price I probably would have used them.

Click to expand...

Yeah 1050 would be a lot. I was quoted $650 to custom bend dual pipe from the manifolds back a couple years ago. Though the cost of the cats was not included in that estimate (since I probably would not have put them back in).

I'm going to update this thread. I got the Walker 53273 replacement assembly installed.

One of the manifold studs broke so I ordered the Nickson 17351 Clamp-A-Stud 1 1/4-2 3/4 : Amazon.com : Automotive Clamp-A-Stud from Amazon for delivery tomorrow. Thought about ordering Amazon.com: Truck Stud Fix Clamp (1" Diameter) - For Light Truck Exhaust Manifolds: Automotive. I drove it around and currently have no leaks. It's about 60 miles round trip to get home and back to work tomorrow where I can put the Clamp-A-Stud on. We'll see how it goes. One of my Business Neighbors has a torch and I was hoping they would return so I could get them to torch the stud but NO luck.

If your tackling this job, without a TORCH, make sure sure you have and Air Chisel, Exhaust Pipe Expander and and Oxygen Sensor Socket. I rented the Pipe Expander and the Oxygen sensor socket from Oreilly's.

You need the air chisel to separate the existing pipe where it goes into the other side. Or at least I did. I could get it to wiggle but that was all. It wasn't coming out. I also messed up the wires on my front Oxygen Sensor while wiggling it. They are awful close to the heat shield. I ended up cutting the exhaust pipe near the junction and using the air chisel to split the remaining piece where I could compress it and dig it out. The last time I did any exhaust work, I remember now how bad it sucked. I was younger then...probably 14 years ago.

You need the tailpipe expander to spread the pipe that it inserts into back open slightly, since the clamp slightly crushes the pipe.

I have to thank the Ford engineers for making one of the Transmission Crossmember Nuts impossible to get a power/air tool on. Making it necessary to make baby turns with an 18mm wrench to get the nut off.

I did this on the ground, with the front tires on about 5 inches of wood and jack stands under the rear axle. A lift would have made the job much easier.

It didn't look like the inside of the cat was broken up enough for anything to travel back through the rest of the exhaust system. I couldn't get anything to shake out of the rattling one when I got it out and the pipe cut off it.

Thought I would add....

I got a quote of $70 for both cats from SellYourCatsDirect.com SellYourCatsDirect.com - We buy scrap catalytic converters nationwide! they pay the shipping.

They are going out in UPS today!

I was telling a friend about the site and he figured it was a chinese resturant looking for cheap meat! But...they are paying me about $4.67 per pound. So, I figure they could get chicken cheaper....