Exhaust rattle

[iainmcphersn]

I've got a rattle coming from the left side of the engine compartment. It's not constant, just happens when I'm accelerating and hit around 2500 RPM. Any idea if it's a loose shield, etc or something major?

2003 Protege5, standard 2.0L engine, no mods, 144K miles

Thanks!

 

[CheeseHelmet]

Heh, good luck finding it. These cars are notorious for having random rattles.

The first thing you'd want to check is the exhaust manifold heat shield, mine rusted away and was barely hanging on. Then check the heat shield around the secondary catalytic converter, poke it with a broom handle to see if it's loose (mine fell off after mild poking). Finally there's the heat shield(s) around the j-pipe which could also be loose.

If the noise isn't too loud I would just ignore it, you'll go crazy trying to track down random rattles.

 

[meGrimlock]

what is the solution once you isolate the rattle? tighten bolts? new bolts if they are rusted? could new rubber hangers also help if the existing ones are old? thanks

 

[tweety2300]

If its a heat shield pull remaining bolts off it that are holding them on remove it. Take a hammer beat the s*** out of it for the aggravation it caused you. Throw it away shut you hood wash your hands and drink a beer

 

[meGrimlock]

there is more than 1 heatshield in the exhaust system and i'd prefer to keep them intact. the heatshield between the midsection and shifter has some bolts that spin freely, could this be the cause of some exhaust rattle?

i dont mean to thread jack, im just trying to pinpoint my rattle too, and hopefully iainmcphersn may have some experience with this as well?

in the attached pic, i've highlighted the bolts that spin. i can't tighten or loosen these:

 

[tweety2300]

if you have a bolt that spins freely it may have rusted/ striped the threads out. you could rethread or weld it if you really want to keep it but it doesnt really do anything. and there are 3 one on the heady one on the pre cat and one on the main cat. dealing with the rattle mine has till it goes under construction for the susp. unless it gets worse like the one on the header did

 

[madmaz]

Ohhhh don't even get me started on rattles...Listen to this, the 3 bolts holding the j pipe to the exhaust manifold can rusted so badly that the j pipe is loose and rattles all the time. Now Madmaz has to drill the studs out and put a new gasket and studs/nutz. I seriously need to start a ranting thread about mazdas and their rust!!! I can't take it anymore; just this one more winter and part out, scrap, or sell cheap.

 

[tweety2300]

Well your in canada here in va rust isn't a big problem except for the exhaust

 

[meGrimlock]

with the car off, i looked under again, and found the j-pipe (or front pipe) after the pre-cat that made the same rattle noise when i would tap it with my fingers. this is the same j-pipe cheesehelmet and madmaz is talking about.

further inspection saw 2 bolt holes were rusted thru, so the bolts were still on the pipe but the heatshield was not. it was resting on the 3rd bolt which i tried to tighten but the act of using the wrench sort of twisted the bolt off.

so the heatshield fell off, bolts are rusted, and there is nothing i can do to fix it short of getting a new j-pipe or some high temp epoxy. turned the car back on and no rattle (well, at least this rattle, now i have to hunt down the others).

see attachment, it is the part labeled #4 that i removed. hope it helps

 

[CheeseHelmet]

with the car off, i looked under again, and found the j-pipe (or front pipe) after the pre-cat that made the same rattle noise when i would tap it with my fingers. this is the same j-pipe cheesehelmet and madmaz is talking about.

further inspection saw 2 bolt holes were rusted thru, so the bolts were still on the pipe but the heatshield was not. it was resting on the 3rd bolt which i tried to tighten but the act of using the wrench sort of twisted the bolt off.

so the heatshield fell off, bolts are rusted, and there is nothing i can do to fix it short of getting a new j-pipe or some high temp epoxy. turned the car back on and no rattle (well, at least this rattle, now i have to hunt down the others).

see attachment, it is the part labeled #4 that i removed. hope it helps

Awesome!

Don't worry about that heat shield, it's USELESS unless you regularly stuff piles of flammable material under your car after driving it. In fact, most (if not all) aftermarket j-pipes don't come with any heat shields. Stop worrying and enjoy your slightly less noisy car

 

[i12drivemyMP5]

there is more than 1 heatshield in the exhaust system and i'd prefer to keep them intact. the heatshield between the midsection.....

Speaking of this heatshield.....I didn't have loose bolts but I did have a decent sized rock that managed to find it's way up between the shield and bottom of the car. This stupid ass rattling worked me over for quite awhile. Thank goodness I found it when having a hi-flo flex'd cat'd midpipe made. Have a look see to make sure nothing got up in there.

 

[esnave09]

I didn't want to threadjack either, but I feel mine is related to this too, since there are so many possibilities to what this could be.

Well, I finally found the (or one of the many?!?) source(s) of my rattling after about 2 months of being driven crazy at stoplights holding the gas so it would be quiet! I'm having the same problem as iainmcphersn tho, where it rattles when I hit somewhere between 2500 or 2800 RPM. Mine turned out to be a j-pipe that rusted so bad it actually severed itself from the rest of the exhaust around one bolt and was loose! How it happens on one side but not the other is beyond me, but it makes the same sort of rattling when I hit it with the rubber handle of a hammer. Anyone know of anywhere besides the overpriced dealer where I could get one to replace it myself? And is it really called the j-pipe, or is it something else? Not to be nit-picky, but when I looked at it and searched Advance Auto Parts, their j-pipes were literally shaped like J's and mine's more like a funky L.

Here are some pics of what mine looks like (sorry, they're not the greatest quality - My phone camera sucks). You can clearly see where the part is severed near the one bolt on the left and suprisingly not rusted almost at all. Does this mean the previous owner tried to replace it (I just got the car 4 months ago) or just that something broke off:
This is where it was severed/broken/whatever the heck happened there:

This is the whole part (notice the ridiculous amount of rust for spending the first half of it's life in Florida before moving to Minnesota):

And the other side specifically:

 

[pcb]

If it were me and you don't mind doing a "Jerry Rig",.. I would cut both of those flanges off and install on of these:

Chances are really good you'll end up having to replace a lot more than you realize if you do it the "proper" way just getting the broken piece out. You may end up replacing the entire exhaust system.

 

[pcb]

there is more than 1 heatshield in the exhaust system and i'd prefer to keep them intact. the heatshield between the midsection and shifter has some bolts that spin freely, could this be the cause of some exhaust rattle?

i dont mean to thread jack, im just trying to pinpoint my rattle too, and hopefully iainmcphersn may have some experience with this as well?

in the attached pic, i've highlighted the bolts that spin. i can't tighten or loosen these:

I had that exact thing happen to me. The bolt goes into a weld-nut on the other side of the body and it gets so rusty the weld breaks instead of unthreading.

I was trying to get underneath it to acces my P-Brake cable and shifter for service and wanted to keep the shield in place to help keep dirt and water and even heat off those parts.

I ended up cutting slots in the heat shield from the bolt hole to the outer edge with a rotary tool and the bolts were loose enough to slide the shield out from under the bolt heads. The shield has enough give to do this to each corner then I could move it out of the way to access the shifter and cable.

When I went to reinstall it I slide each corner back under the bolt heads then used some mechanics wire to wrap between the bolt head and shield to stop any rattling.

I've had the shield on and off a few times already since and reinstalled it with new wire easily.

OR,... you could just throw it away and have a beer like tweety said.

 

[zackmac]

thought i'd join in on the fun...

when installing my TWM short shifter I had to remove the same nuts to put spacers on the heat shield... broke off the same as previously mentioned in the thread (now i know this... thought it was just me haha)

so instead of trying to fix it just for a damned heat shield and 1 inch spacers, i took a sawzall and cut it off... and didn't spill my beer in the process



here it sits in my room, 3 out of 4 sides were cut with a sawzall, the other one was forced out by some serious prying.

It's been a month and no problems, although people have said they have been running it for 3 years + without a heat shield and no problems

+1 for the cut it off and have a beer idea

 

[esnave09]

If it were me and you don't mind doing a "Jerry Rig",.. I would cut both of those flanges off and install on of these:

Chances are really good you'll end up having to replace a lot more than you realize if you do it the "proper" way just getting the broken piece out. You may end up replacing the entire exhaust system.

I would, except I have to drive my car delivering pizzas, and my manager wasn't happy when he heard the noise my car was making. And I don't own something to cut those flanges off. But hopefully I don't damage anything else. I actually got sick last night after driving for some 6 hours. On the slightly bright side, though, the other flange on the front pipe snapped as well, so that should make it a little easier to take off. Let's hope I can finish this in an afternoon without too much trouble.....