Why does my 1997 Jeep Wrangler rattle?

Question

It's got 60,000 - 2.5L 4cyl auto
about a month or two ago, a loud rattling started when i first start the engine. The rattle goes away when i rev over about 1500rpms. It sounds like its coming from the catalyctic converter, but the heat shield is firmly on. is my converter going? do i need a new one? sigh...

Answer 1

It could well be the cat. I've had two fracture on me and they both went quiet after a few minutes once the exhaust system had warmed up. Get underneath and hit the cat with a rubber mallet or the flat of your hand to se if you can hear it rattle. Cats (a major emissions component) should be covered for 80,000 miles, so it might be worth taking to the dealer if it's the cat.

Answer 2

wrong.... On Jeep Wranglers and Cherokee both 2.5l on 4.0 the rattle is the waffer boards inside the cat. Replace the cat and you shall be pleased. I have had 1 wrangler, 2 cherokees and 4 Grand Cherokees and everyone started to rattle after so many miles

Answer 3

Had a 93 wrangler same engine same problem. It was the catalyctic converter.The insides had busted and was rattling around. you could also hear it rattle when going over bumps. If it is your catty you need to replace it as soon as possible because it could become blocked and this will cause the engine to die and not crank until the blockage is removed. Hope this helps.

Answer 4

It is doubtful that you need a new cat.

There are other heat shields that could be loose. Are you sure it is not valve rattle?

But to be sure check for recalls on this model.

Answer 5

I have an '07 that rattles. It is just a Jeep sound.

Answer 6

it could be the cat. converter but the noise would get worse when the cat gets hot