I have a friend who owns a 1997 Dakota Sport, auto transmision, 3.9l V6 with 77k miles. The only problem is, it has a very loud rattling that seems to show up when at low RPM's, such as idling or when moving slowly. (I don't believe the sound is heard at over 15mph). Anyways, the guy he bought it from said it was the catalyctic convertor. Is this correct? If not, what IS making the rattling noise? Can it be fixed easily/cheaply? I would greatly appriciate any help! Thanks!

 

i have a 97 3.9 135,000. its been doing it since it rolled out the factory. its not the cat. its the lifters or something. bottomline ; save your money its fine!

 

I bet the guy is right. Whenever you have a loose part of the exhaust system, it will rattle. Have someone have their head down low so they can pin-point where the sound is coming from. I doubt it is the engine. It has to be part of the exhaust system.

 

I would believe the guy. It definitely sounds likea cat. con. to me. Mine went out at around 115,000 miles. It would rattle really bad at low speeds and bog down pretty bad. One thing I would do is get a rubber mallet and tap the cat a few times to see if you can hear a faint rattle. If you can then its the cat. Also, after its been running a while the cat might turn cherry red so tell him to look at night after its been running. This is another sign it has gone bad.

My buddy has a 96 ford escort that has major rattling issues. We found a huge crack right before the cat on the exhaust. Its a POS so he isnt going to fix it at all, but its loud and rattles a lot. Probably not a good thing

 

If your engine is ideling and you put your head by the front drivers wheel and you can hear a rattle, more then likly it is the timing chain. All 1997 dakotas do not have a timing chain tensioner so when the chain gets slack it hits against the housing. To verify remove your belt and start the engine. If you can still hear it im 99% sure its the timing chain. I know because i replaced one on my old truck. I did the job myself. It took me about 6hours and it really wasnt that big of a job. Make sure you buy a "double roller" chain. you dont need to buy a tensioner with that chain as it doesnt strech. This site hear is a great "how to" http://www.pavementsucks.com/tech/timingchain.php
It cost me about 150$ for all parts at napa.

 

do the hammer thing, mabie a heat sheild