My 99 2500 V10 has a rattling sound at around 2000 RPM, when the load is light or between shifts. Sounds like valve train noise to me. As I looked on line for ideas on this i found many of the same noise complaints from the catalytic converters. Whats your thoughts on this? Could this rattling noise travel up the head pipes and sound like its in the engine?

I was looking into this noise today in the shop. If i feather the throttle under the hood it sounds like a Diesel. I did crawl under the cats and at idle they are making a metal rattle sound like the insides are falling apart. Anyone ever deal with this?

Tap on the mufflers to see if any catalyst broke loose and mad it's way back.It can clog the muffler and drop power.

I did beat on the exhaust in a few places but could not hear anything. The cats only rattle when the engine is at idle. Also I should add that there is no noise in the engine area at idle.

Broken up cats were common in that era truck.

Broken up cats can come up the exhaust and into the cylinder where the ceramic substrate does quite an interesting job of machining the cylinder/piston top. Check it out NOW.

R.

time for cat delete

Thanks for the replies. Still not sure if this could cause the noise I'm hearing in the engine but I do know that its a problem and should be an easy fix. What would be a good performance replacement? Also i would consider just removing them but what about the air tubes? This truck has the dual head pipes and cats into one huge muffler and tail pipe. All original.

Have you tried using a mechanics stethoscope to locate the noise source? You can pick one up pretty cheaply at the local parts store.

Odds are that the cats are bad anyway.

My 99 Ram 2500 V-10 the cats were rattling.
I eliminated them and the air pump which fed into them.

It ran better afterwards, imagine that.

crossfire on ignition wires beating the rod bearing on #7.

Tell me more about this cross fire..... Never hear the noise at idle, never under load, only when the engine is free revving around 2000 RPM, either in neutral/park or that few seconds between shifts. Even though the exhaust is starting to rattle inside I'm just not sure that its the noise I'm hearing up front.

Thought I would give an update. I talked to two local exhaust shops today and they both listened to the truck. Both stated pretty much the same as the guys here... Converters.

The first guy said its very common and that the inner liner burns out and they start to rattle, But he wasn't completely sure on my cats, but thought the muffler was rattling on the inside. He said pull the muffler and then check cats.

The second guy said replace it all. Cats and muffler are both loose on the inside. He said they have had trucks come in that sound like a rod is going to come out the block and its just bad cats.

I had said earlier that I would start with the exhaust because it would be an "easy fix" WOW I had no idea how expensive this would be and the lack of available exhaust parts for the V10 trucks

I would start by cutting out the cats, then start it up and see if there's a rattle anymore.

After I cut out the cats on mine I started it just to see how loud it was.
It wasn't as loud as I was expecting it to be.

Yes, I agree. For what they quoted me I cant go wrong. I would rather do it myself, It just takes longer...

If you don't have to deal with any type of emmisions inspection on the truck I would just eliminate the cats, which is what I did.

I have the same rattling noise at 2100 when I feather the throttle or between shifts.Took the cats of same noise.I had a very experienced mechanic tell me it is the air exchange in the intake.I think it sounds like the timing chain loose and hitting the cover.My truck only has 86000 miles on it.

Thought I would give an update here. Got a deal on a complete cat back exhaust from Gibson. So I pulled the tail pipe off and then the muffler. The muffler was not loose on the inside but the converters were. I fixed that and started the truck with no muffler. It was loud... I was in the shop across the yard with the doors shut and the kids could hear it in the house. I didnt notice the rattling sound so I thought all was well. I installed the new Gibson muffler and reused my original tail pipe, because it was one piece and had the heat shields for the spare tire.

It sounds great! But the noise is still there...

Never hear the noise at idle, never under load, only when the engine is free revving around 2000 RPM, either in neutral/park or that few seconds between shifts. Even though the exhaust is starting to rattle inside I'm just not sure that its the noise I'm hearing up front. [/quote]

So now what? In the end the exhaust was an easy fix but like i said before I just don't see how that Diesel sound could travel up the pipes and into the engine...

One thing i did notice is that the engine has to be hot to rattle. I still think it sounds like valve train but could that come and go under load? Could the injectors make loud chatter?

I had a similar issue a few years back on my '02. It would warm up then starting pinging under part throttle operation. I took it to a local ex Chrysler mechanic who determined it was the computer. For what ever reason it would move the timing around regaurdless of the inputs. My extended warranty was expired and at 40k miles bit the bullet for a reman computer. End of problem.

Thank you for the info. I have not given up on this issue. Its funny you bring up timing, as I was just talking to my dad about timing the other day. I would guess that a dealer would have to plug into the truck to "see" what the timing is doing while running?

Mine makes the exact same noise. Been doing for years.

I was fortunate this independent guy had good equipment, but even then he took it to another shop to confirm it.

Just wanted to give an update... This summer I had a dealer listen to the truck. He said the timing looked good. He was able to shut off an injector in each cylinder one at a time. He could produce the rattle noise on #2 and #9. He said he thought it was the flex plate rattling. Said it must be cracked...

Any thoughts on this?

How about possibly a timing chain rattling? Although they usually can rattle at idle, but being a 10 cyl, maybe they are in their own orbit on symptoms?

The tech never said anything about the timing chains on these engines. He didn't believe anything was wrong inside the engine. We both listened to the rattle and It does sound like its coming from the rear... I guess my question is how can i know for sure it is the flex plate? I took the cover off and cant see any cracks. He said it would crack around the crank bolts, And you cant see them from the bottom.

If I took the torque converter bolts out and pushed it back, could I run the engine to see if the noise is gone? Is there enough clearance for that?

Pull the trans. If you were to run the engine disconnected from the torque converter you will gall the pilot hole in the crank and the converter hub and without any load on the flex plate it may not make any noise.

Thank you, I figured there wouldn't be enough clearance. That's a lot of work to pull it back just to look but I don't have any other options do I? Being able to run it without load on the plate was the reason I wanted to try that.

If it is the flex plate the next problem is they are discontinued.... Is there any aftermarket options, or am i looking for a used one?

Try a google search you can probably find one on ebay.

My 96 V10 Ram has 168,000 on it now, the cats have been rattling for years. I just turn the radio up louder. LOL. One of these days I will just delete them. They do not seem to effect power or performance thus far.

Get rid of the cats.probem solved

IF you read this post from the beginning you will see that I did fix the exhaust. That was not the problem. A tech said he thinks its the flex plate. I'm looking for thoughts on this... As in are these flex plates know to crack? How Can I know for sure with out pulling back the trans? This truck only has 80,000 miles.

Ok get it running .get under there with a piece of hose stick it to your ear.that should pinpoint your noise

IIRC you should be able to see a fair amount of the flexplate with the dust shield off the lower bellhousing.

Do a visual inspection and then do another check with it running to see if you can isolate the noise to the bellhousing area.

I did do that earlier today. I had the cover off and ran it. It looks good but you can't see the center where the crank bolts are. I will admit its very loud with the cover off on start up, then the noise goes away.... I'm in the process of pulling the trans back. I will report what I find.

Its not the flex plate. I think I found the problem though. I pulled the pan off and the rod bearings seem too loose... I will investigate more when I have time. Didn't expect that as it has really good oil pressure.

I thought it odd, that a tech would think it was a flex plate when the noise went away when dropping #2 or #9 cylinder. Wouldn't a flexplate make noise all the time the engine is running? I would investigate these 2 cylinders. Possibly loose bearing (like you suspect), wrist pin, or piston-cylinder clearances.

It was actually just the opposite. No engine noise when at idle. He would shut off the cylinder and it would rattle. Turn it back on and the noise would stop. I did ask about wrist pins that day and he did agree that yes when an engine would come in knocking as they turned off the cylinder it would go away. He thought the engine just ran to smooth to be internal. He felt that as they turned off the cylinder the missing was shaking the crank and the possibly cracked flex plate.

I have been trying to figure out this rattle for like 4 years. I have asked here, other dealers and shops, everyone said it was exhaust rattling, nothing or normal sounds.. I drive trucks every day and just never believed this was normal "sounds". Never wanted to just start taking everything apart without knowing for sure what was wrong.

Have you checked your timing chain.I have the same problem and my chain is very loose at 85,000 miles.Had a gold star Chrysler mechanic with viper training check it and back me up on it.He says they used a poor quality chain from the factory without a tensioner.You can see it with the oil pan off.

I will look at it more this week. I didn't look to closely at the chain but I did see it when looking up from the bottom. Didn't notice anything unusual about it. But now is the time to be sure when its all apart.

Did you check the timing chain.I think the spec is 1/8 inch slop

Yes, It's a little loose. Was looking For a replacement and all I see is just the chain... I thought that was a no no? Didn't find any listings for a chain and gears set...

The rods are all showing brass and some are down to the metal on the bearing shells. None of them were spun. The mains look perfect. The first rod Journal has a small step on it and is too deep to fix, so I ordered a different crankshaft. I'm finding there is not much for parts available for these engines

Never really was. Hope you find what you're looking for.

There are things that interchange with the magnum small block but I don't know exactly what. Timing chain and gears may be one such thing.

A quick cross reference on rock auto shows they both use the same chain so an aftermarket set for a small block should work for you.

The magnum set won't work. The chain may be the same but the upper sprocket has the ring cast on it for the cam sensor. What I have found is that you can buy the chain, and the lower sprocket separately from Napa, but not the upper sprocket. I did find a timing "set" listed for this from Auto zone #73153. Not for sure that they can even order it still... Or who even makes it. Anyone have any opinion on the quality of their parts?

Autozone's website says that they're available.

https://www.autozone.com/internal-engine...odel=&year=

They even list them on Ebay with two different number and prices.

https://www.ebay.com/itm/Engine-Timing-S...qGq&vxp=mtr

https://www.ebay.com/itm/Engine-Timing-S...kS1&vxp=mtr

Problem solved... I did order that timing set from Auto Zone. It said Made in the USA on the package but not sure by who. It looked good and was almost identical to the original. Dropped in the new crank and bearings and ran it yesterday and drove it to town today. It hums like a V-10 with no funny rattling noise between shifts. The engine had a little lifter noise on start up before too and that is also gone now. I know now that the engine oil was bleeding down from the loose rods when it sat.

After all these years of wondering what it was, I'm happy to be done with it.

Glad to hear you got it fixed and glad you updated your thread. Too many people don't do that.

You replaced crank in chassis? How difficult was that?

No, I pulled the pan in chassis but when i realized what was wrong I ended up pulling the motor out.

Glad to hear that you got it figured out and it's now fixed.

....and make sure you use GOOD plug wires and route them correctly. We used to see crossfire hammer rod bearings out of these things.