Yet another 4th gen cat rattle thread

[xxaarraa]

Alright guys, here's an update. Both the Toyota gaskets came in and I went down there today to install them.

The front (upstream of the y-pipe) was a no-go. The two connectors were held together by a weird torx socket (#8 e-socket) threaded rod/bolt going through a 14mm nut. I have never seen an arrangement like that. I tried removing both, but neither budged. They seem to be torqued like a mofo. I didn't want to strip anything so left it alone.

The rear (right near the muffler and resonator) was rusted beyond repair. Couldn't even make out what size and type of bolt. So left that alone as well.

I am going to have to take it in to Toyota to deal with this.

 

[sonerick]

Exhaust work is fun, isn't it?

I think those strange bolts might be a security feature, so it's not as easy to steal your catalytic converters. They've also been heat-cycled a lot, so they're probably frozen together pretty good.

The rusted bolts are probably going to have to be cut or chiseled off and replaced judging by your description.

Didn't [MENTION=105200]Ohcrymore[/MENTION] say he had this issue? Which gasket did it end up being, and any tips for removal of these bolts?

 

[xxaarraa]

Exhaust work is fun, isn't it?

I think those strange bolts might be a security feature, so it's not as easy to steal your catalytic converters. They've also been heat-cycled a lot, so they're probably frozen together pretty good.

The rusted bolts are probably going to have to be cut or chiseled off and replaced judging by your description.

Didn't [MENTION=105200]Ohcrymore[/MENTION] say he had this issue? Which gasket did it end up being, and any tips for removal of these bolts?

Thanks for the pointer, I found ohcrymore's thread and read through all of it. The only things I can think of checking on my truck are:

1. Exhaust manifold heat shield? "Replaced my exhaust manifolds with pacesetters & no more noise . Lost the shields on that part of manifold"

Where are these manifold head shields? Inside the engine bay?

2. Drive shaft u-joint heat shield? "there is also a small guard/shield just forward of the t-case that protects the universal joint for the front drive shaft. give that guy a check as well."

I know where that is and will check it.

3. Removing / checking skid plates. "Removed the skids in case they might have been lose, but that was not the case and have re-installed them"

I am surprised I didn't think of this before. I have full 5 piece budbuilt aftermarket skids and I recently (3 months ago) had one of them off to install swaybar links. I am going to remove the front and mid skid and see if the noise goes away.

4. Brake pads being loose? Check your front calipers. If several of the pistons are frozen, your brake pads will rattle when you hit bumps... I had a similar rattle/clanking noise... fixed when I replaced the front calipers

This would be the most worrying, if it turns out to be the issue. Interestingly, I am also getting brake pulsing after only 10k miles since last full brake job (rotors, pads and calipers). I chalked it down to the cheap rotors I bought on amazon, but could it actually be my calipers are frozen again? I suppose I could visually check for a frozen caliper correct? just pull the wheel off, caliper off and check where the pistons are?

 

[oljedi11950]

Probably not gonna help you now but when I replaced my manifolds with the pacesetter's I lost this friggin rattle , I thought it was tranny at 1st then decided to replace oem manifolds almost instantly no noise & I'm running the urd y-pipe . So far so good but will comment on pacestter's they don't last long already replaced driver's side but that's a weld issue on the last cylinder small crack at the bend fixable but a hassle .

 

[gg6363]

Check the area around the oil pan. I had a similar problem. To change the oil on a 4th gen it's a bit of a pain. I found that a previous oil change "box" place had sheered a bolt off towards the front of the skid plate oil pan cover. I had to drill out snd re-tap/install another bolt; problem solved.
Hope this helps.

 

[xxaarraa]

OK guys, I think I finally solved this. I say finally, since I tried so many things to no avail including replacing belt, idler pulleys, removing water pump fan etc.

I then got around to cleaning my throttle body, MAF and air filter. What tipped me off to this was the airbox would vibrate when the car was idling, more so than what I thought was normal. So I cleaned everything and noise seems to have gone. Go figure.

 

[fo' runnin']

So, I've got a rattle that continues to persist as well... I can NOT find it. I removed all of the skid plates and the front sway bar, thinking it was one of those... nothing.... I've checked EVERYTHING. Can't find anything lose at all. It is REALLY starting to bother me.... lol

It seems to be something in the suspension or steering because it rattles with the bounce of the tire/suspension when going over little bumps in the road, even though the body doesn't move or bounce when hitting those bumps because the suspension soaks it up.
It's LOUD and by the sound of it, whatever it is seems to be VERY lose. Even the tiniest bump will set it rattling loudly.

I've looked for loose rocks or nuts/washers/bolts laying around under there and can't find anything out of place...

I also don't think it's this "cat rattle" you guys are describing because it ONLY does it while driving, I can't make it do it by revving to a certain RPM or anything. Hell, I've even smashed the tire with a sledge hammer and pounded on just about every part under there trying to send vibrations through the vehicle and nothing makes a sound unless I'm traveling down the road...

Anyone got any ideas?

 

[xxaarraa]

So, I've got a rattle that continues to persist as well... I can NOT find it. I removed all of the skid plates and the front sway bar, thinking it was one of those... nothing.... I've checked EVERYTHING. Can't find anything lose at all. It is REALLY starting to bother me.... lol

It seems to be something in the suspension or steering because it rattles with the bounce of the tire/suspension when going over little bumps in the road, even though the body doesn't move or bounce when hitting those bumps because the suspension soaks it up.
It's LOUD and by the sound of it, whatever it is seems to be VERY lose. Even the tiniest bump will set it rattling loudly.

I've looked for loose rocks or nuts/washers/bolts laying around under there and can't find anything out of place...

I also don't think it's this "cat rattle" you guys are describing because it ONLY does it while driving, I can't make it do it by revving to a certain RPM or anything. Hell, I've even smashed the tire with a sledge hammer and pounded on just about every part under there trying to send vibrations through the vehicle and nothing makes a sound unless I'm traveling down the road...

Anyone got any ideas?

Heat shield

 

[luke87gt]

just went through this with my 4Runner

changed exhaust hangers, tightened heat shields, tightened luggage rack, tightened interior parts.

ended up being a loose air intake tube that resonated all through the cabin. these trucks transfer noise through the body like crazy which makes it hard to isolate rattles:

http://www.toyota-4runner.org/4th-g...-annoying-interior-rattle-2006-4runner-2.html

 

[xxaarraa]

just went through this with my 4Runner

changed exhaust hangers, tightened heat shields, tightened luggage rack, tightened interior parts.

ended up being a loose air intake tube that resonated all through the cabin. these trucks transfer noise through the body like crazy which makes it hard to isolate rattles:

http://www.toyota-4runner.org/4th-g...-annoying-interior-rattle-2006-4runner-2.html

Glad you found it luke, these are the types of problems that drive us nuts aren't they?! In the course of hunting down this issue, my 4R got a bunch of new parts it didn't need, but hey, new parts are new parts, right?

Good tip on checking mounting for intake tube. Couldn't hurt to put a few thick rubber/nylon washers underneath the mounting bolts on the fender wall.

 

[acronin2]

Exhaust rattle 04 V6

Sorry for reviving an old thread here but I just recently, last night, started to hear a rattle that sounds like its coming from the rear of my truck, passenger side. Its an 04 V6 with about 150k miles. I took a closer look this afternoon after work and it seems to be an exhaust rattle that only happens while in gear at low rpms. I plan to get the truck on jack stands tomorrow to get a closer look and check all the heat shields. However I did notice a small gap where the rear exhaust pipe comes out of the back of the pipe assembly (part 17420 above). I've attached a pic below and also uploaded a video of the rattle noise.

I'd appreciate any input for what to look out for when I get under there tomorrow. I plan to check the y-pipe gasket as well since it seems like this is a common cause of exhaust rattle. Obviously heat shields will be checked as well.

TIA

https://youtu.be/NyacB2hMXts

 

[jemcas29]

After reading through a lot of posts regarding the rattles on 4th gens, I finally found my culprit.

The source of the rattle was loose A/C Compressor bolts. I poked around with a stethoscope and was able to pinpoint the issue.

The rattle was only present while in gear (drive or reverse) in the 500 to 1000 rpm range. Sometimes turning on the A/C made it go away, other times it didn't change it all.

Hope this helps some of you!