Rattle at Low RPMs

Hello everybody, it's me again...

I have a strange noise that occurs everytime I accelerate slowly, or I am driving at low RPMS in first. It sounds like a godawful death rattle
:uhoh: coming from under my car. I have no problems with power/economy, but the noise is horrible. it goes away after I start to accelerate harder, but since most of my driving is low speed/low rpm, i would like to fix it... any ideas other than the cat, which I am gonna check in about 30 mins after my car chills off?

At idle and just off idle, my water pump shaft was so loose it was making a rattle/knocking sound similar to a rod knock, yet it wasn't leaking. It was plenty audible inside the vehicle and in the front. It was even noticable when I crawled under the car behind the front tires. I found it after removing the belt and spinning all the pulleys. Might be worth a try.

possibly a heat sheild when i get cars i rip em off whether their good or not their pointless and always eventually make that horrible rattle that makes your baby sound like a pos i havent been under my new blazer YET! but i will be tomaro so i have no idea what its like yet

aha! it is the cat! Damnit, now i have more money i have to shell out. Oh well.

possibly a heat sheild when i get cars i rip em off whether their good or not their pointless and always eventually make that horrible rattle that makes your baby sound like a pos i havent been under my new blazer YET! but i will be tomaro so i have no idea what its like yet

Pointless? You have lots to learn dude! Think of what they're called HEAT SHIELD!! :lol:

Pointless? You have lots to learn dude! Think of what they're called HEAT SHIELD!! :lol:

pointless, unless your dumb enought to park in tall grass, or touch them, heheh. bet you wont do it twice.

i rip them off also, but not till they start making noise.

out of curiosity, how much does it cost to have a magnaflow universal hi-flow cat installed? (not including the parts cost)?

out of curiosity, how much does it cost to have a magnaflow universal hi-flow cat installed? (not including the parts cost)?


so your saying your noise isnt the heat shields, but from inside the cat?

i dont know, ive never replaced one.

pointless, unless your dumb enought to park in tall grass, or touch them, heheh. bet you wont do it twice.

i rip them off also, but not till they start making noise.

Well when your spark plug wires get brittle and other components that age quickly age even quicker because your tore off a heat shield rather then fixing it properly, you'll know why. Thoese items are there for a reason, your making your own problems!

so your saying your noise isnt the heat shields, but from inside the cat?

i dont know, ive never replaced one.


This may help...but my blazer would rattle when I take off slowly...it sounded like thin metal rattling against something...but my problem was my muffler. It rotted out on the inside. I've had my muffler changed a few times within the last 4 years. Not sure why she goes thru so many...but worth a shot.

i dont beleive a magnaflow exhaust is too bad in price go to a reputable muffler shopand youd prolly get a full cat and back magnaflow for under 300

a heat sheild does exactly the name sheild heat nothing more i dont want to hear it it pointless youll never notice its not there.... theres a console that runs down the center that sheilds heat

Well when your spark plug wires get brittle and other components that age quickly age even quicker because your tore off a heat shield rather then fixing it properly, you'll know why. Thoese items are there for a reason, your making your own problems!


um, yea, your catalitic converter is part of your exhaust system, located under your car, before your muffler, it gets really hot, like 1200 degrees, i think, not exactly sure, but the heat sheild is there so morons dont touch it directly, or if you park in tall dead grass, or a pile of leaves it wont start a fire. pretty sure it wont affect your plug wires at all.

i dont beleive a magnaflow exhaust is too bad in price go to a reputable muffler shopand youd prolly get a full cat and back magnaflow for under 300

a heat sheild does exactly the name sheild heat nothing more i dont want to hear it it pointless youll never notice its not there.... theres a console that runs down the center that sheilds heat


I already have a catback system with 3-inch piping... it's a flo-pro muffler and sounds great... i just need the cat changed and since it is stock, i figured i'd get a high-flow one from magnaflow.... they cost about 50-85 i think. i just wondered how much it would cost to have somebody put one on.

um, yea, your catalitic converter is part of your exhaust system, located under your car, before your muffler, it gets really hot, like 1200 degrees, i think, not exactly sure, but the heat sheild is there so morons dont touch it directly, or if you park in tall dead grass, or a pile of leaves it wont start a fire. pretty sure it wont affect your plug wires at all.


GOLLY your one smart cookie!! I think everyone knows that the spark plugs dont mount to the exhaust! Your missing the point i'm trying to make, and FYI they put the heat shield above the exhaust!! Imagine if there were no heat shield. Think of your gas line and brake lines!! You do know that your so called 1200 degree muffler can boil brake fluid? Well im going to assume that the engineers at GM have no f-king clue what there doing! till next time :screwy: :lol2: :banghead:

the lines and wireing were set to be away from the exhaust... heat sheilds are pointless their metal the get hot and send off heat just as much........ maybe if they were made of something that dispersed heat more efficently...... but i do agree with the heatsheild surrounding the header but you were referring to the wrong heatsheild we remove the one under neath for the exhaust.... i have the look at the one for the headre closer... i think that one might make cooling the header with free flowing air more difficult thus being the heat sheild is sheilding heat and cooling

Also experience a quieter rattle at 1000-2000 RPMs. On this 98' it's the belt tensioner.

pointless, unless your dumb enought to park in tall grass, or touch them, heheh. bet you wont do it twice.

i rip them off also, but not till they start making noise.
I ripped mine off while changin the plugs. I also have same rattle. im thinkin either the heat sheild i diddnt take off on passengers side or H2o pump or cat. not sure yet.

GOLLY your one smart cookie!! I think everyone knows that the spark plugs dont mount to the exhaust! Your missing the point i'm trying to make, and FYI they put the heat shield above the exhaust!! Imagine if there were no heat shield. Think of your gas line and brake lines!! You do know that your so called 1200 degree muffler can boil brake fluid? Well im going to assume that the engineers at GM have no f-king clue what there doing! till next time :screwy: :lol2: :banghead:


well, dont know about yours, but my fuel lines are on the opposite side of the exhaust system, and im talking about the heat shields on the catalitic converter.

you may also might want to check your tourq converter bolts it happened to mine that way.

the lines and wireing were set to be away from the exhaust... heat sheilds are pointless their metal the get hot and send off heat just as much........ maybe if they were made of something that dispersed heat more efficently...... but i do agree with the heatsheild surrounding the header but you were referring to the wrong heatsheild we remove the one under neath for the exhaust.... i have the look at the one for the headre closer... i think that one might make cooling the header with free flowing air more difficult thus being the heat sheild is sheilding heat and cooling
ALright everyone i think i have the answer for this.. My good friend has a 94 Bravada and he had something similar happen to him. We thought the sound was coming from the cover of the torque converter so we removed the cover but the problem/niose continued. After further listening to the "death rattle" i was alarmed that maybe (JUST MAYBE) his oil pump pickup may have fallen down inside the oil pan and when the engine revved it stopped since the crank and oil spray would knock it out of the way... but, that couldnt be it since there would be a loss in oil pressure... My second idea (and subsequently the right one) was that the flywheel flex plate was coming apart and that the noise was the sound of the cracks in the flywheel grinding as the thing wobbled at low RPM. When the motor was revved up, the noise went away as the centrifical force would take over and hold the flywheel out and the grinding would stop. But as soon as the engine returned to idle, the sound would come right back (and it was horrible it sounded like 2 peices of sheet steel grinding, end to end). After some checking we found a shop that would replace the flywheel for $325 and that fixed it... Heck the shop even put in a new front seal in the tranny for free since they had it down for the flywheel swap.. It was a tough call since you cant see in there but thankfully it was correct. The shop saved the flywheel and it had cracks connecting 3 of the 5 holes cut in it so it was just about to come apart violently. This may not be your problem... but maybe it is.... rattles can come from anywhere for any reason.

Had the same problem at idle and it turned out to be my cat.Let it go and it eventually stopped. Only because it clogged it. Ended up costing me $325. Change it now.

okay, here's the culprit... for anybody interested... it was where the cat connected to the headers... the clamp was rusted off, and the smaller header pipe was rattling loose in the larger cat pipe. i got a friend to weld it, so there is also no exhaust leak... problem solved... now i have to post a new thread because another new one showed up...

okay, here's the culprit... for anybody interested... it was where the cat connected to the headers... the clamp was rusted off, and the smaller header pipe was rattling loose in the larger cat pipe. i got a friend to weld it, so there is also no exhaust leak... problem solved... now i have to post a new thread because another new one showed up...


aw man, the suspense is killing me, ive been waiting like 15 min for the new thread.

yes, thats how bored i really am.

Awwwww man, its over...... oh well i am glad he found the Death Rattle.