stange experience with 4runner the last few days

[hinmo24t]

I had a heat shield type sound i tried finding after some advice on here, but couldnt dial it in (tough when the noise was prevalent when in gear, for self diagnosing) turns out the tail pipe from behind the muffler disconnected at the muffler.
she is still quiet luckily and tailpipe is now on rear seat...will look into a catback or have that welded back on by my mechanic around inspection time.

heres the weird one:
for 2 days, i had a grinding/rotational sound/almost a binding/felt in my steering wheel slightly when turning, low speeds up to maybe 40 i could hear it. i suspected a u-joint going bad on drive shaft. my boss let me stop at my mechanics while i was out in the field before heading back to my office and CLASSIC the sound went away on my startup and drive to mechanics, first time in 2 days. didnt make the sound for him - they pumped drive shaft zerks and he did a nice inspection of my rig on the lift. the sound is completely gone and the greased zerks feel nice. im hoping the sound doesnt return but will bring it to him if so. wild. i was suspect of u-joint or rear wheel bearings. crazy morning, hope it doesnt return.

he released rear pumpkin fill bolt and said i had some gas in there that released (i have a new breather i was going to extend but the tubing i bought on amazon was stiff to go over breather junction so i bailed, anyone know if you have to heat that gas line?). Debating just replacing the breather i have in current location... not sure if binding could come from this. he said the gear oil looked a little cloudy so i will be replacing my gear oil now. he looked at tcase oil and it looked good.

i lightly wheel my truck almost every weekend, through water.

anyone want to comment on any of this rambling feel free - this is what happens when im at work and get a few seconds with a real keyboard lol.

-Tom

 

[rwh963]

i may have had a similar experience. in the end, turned out being an underbody silver heat shield (i guess it is a heat shield) came loose and was sitting on top of the rear drive shaft. silver aluminum about one foot by 3 feet. the mounting holes in it had rotted and it dropped from the underbody.

 

[hinmo24t]

i may have had a similar experience. in the end, turned out being an underbody silver heat shield (i quest it is a heat shield) came loose and was sitting on top of the rear drive shaft. silver aluminum about one foot by 3 feet. the mounting holes in it had rotted and it dropped from the underbody.

thanks. i was under there with a headlamp recently and looked at a bunch of hangers and shields...ill double check for ones above drive shaft - i saw some of those silver ones, maybe the one youre referring to. the metal on metal vibrating early in my post seems to have gone away...im thinking theres a good chance it was from just before that last bit of exhuast behind muffler broke away.

the rotational grinding was the bigger mystery in all this - or concerning at least...seems to have gone away at a very ironic time. hope it doesnt come back. truck has mud on it from last weekend still - saw something somewhere that debri can get in brake shield, hoping a pebble was in there or something (rotational sound)...it also increased with the gas pedal

 

[That_Titanium_4RNR]

Maybe your ebrake stuff?? Mine made weird noises under 20 mph

 

[hinmo24t]

Maybe your ebrake stuff?? Mine made weird noises under 20 mph

i hope not! will confirm that is still working normally. thanks.

 

[rwh963]

the rotational grinding you mention was exactly what i experienced. due to the rotation of the driveshaft during driving, the noise was constant. pulled out the shield, no noise!

 

[Terminator03]

Sorry I can’t help beyond the suggestions already posted, but that thing that happened with your tailpipe happened to me as well! I was towing a trailer up to NH, and started hearing this god awful metallic sound, and swooshing noise that seemed to correspond to accelerating. Being that I was also towing a trailer, it was yet another thing to troubleshoot. Luckily it didn’t take long to realize it was coming from the tailpipe that sheared at the muffler outlet! Unfortunately, I couldn’t get it out from over the rear until I got home, so I had to bungee it in place to control the rubbing and rattling. That was what gave me the excuse to upgrade to the TRD duals, so other than the big price tag, it was a happy occurrence for me. Of course convincing my wife it was worth the extra cost over a stock replacement was a whole other thing!:bounce: Not sure, if you care about the sound, but this may be a good time to consider doing a Gibson, or Magnaflow, or similar upgrade. My only advice there, is definitely spend the extra for stainless, or you’ll be doing it again in 3-4 years...

 

[hinmo24t]

Sorry I can’t help beyond the suggestions already posted, but that thing that happened with your tailpipe happened to me as well! I was towing a trailer up to NH, and started hearing this god awful metallic sound, and swooshing noise that seemed to correspond to accelerating. Being that I was also towing a trailer, it was yet another thing to troubleshoot. Luckily it didn’t take long to realize it was coming from the tailpipe that sheared at the muffler outlet! Unfortunately, I couldn’t get it out from over the rear until I got home, so I had to bungee it in place to control the rubbing and rattling. That was what gave me the excuse to upgrade to the TRD duals, so other than the big price tag, it was a happy occurrence for me. Of course convincing my wife it was worth the extra cost over a stock replacement was a whole other thing!:bounce: Not sure, if you care about the sound, but this may be a good time to consider doing a Gibson, or Magnaflow, or similar upgrade. My only advice there, is definitely spend the extra for stainless, or you’ll be doing it again in 3-4 years...

lol thanks for sharing. i know what you mean about not getting that section out while you were on the road...the mechanics were barely able to get mine out of there at the shop, but did and i threw it in back seat in case i choose to weld it back on by him down the road. i definitely thought aftermarket catback right away...but for the suv application (v6) ill consider welding it back on if its a lot less than a new catback. if its close ill get a new one!

 

[montijo505]

The rotational/mostly when turning grinding noise is most likely a front wheel bearing. Have them looked at. Pretty easy to diagnose if you have a jack. Just lift the tire off the ground and see if there is any play when you push/pull at 3 and 9 o clock. If there is, it’ll need replacing. You can buy the whole bearing assembly and they’re not bad to install.

 

[hinmo24t]

The rotational/mostly when turning grinding noise is most likely a front wheel bearing. Have them looked at. Pretty easy to diagnose if you have a jack. Just lift the tire off the ground and see if there is any play when you push/pull at 3 and 9 o clock. If there is, it’ll need replacing. You can buy the whole bearing assembly and they’re not bad to install.

that makes sense but i did see mechanic do exactly that...was impressed with the walkaround they did while i was invited into the bay. he looked over the entire undercarriage, greased zerks, open tcase and rear diff, lifted front and looked for play at 3 and 9 (6 and 12 reveals something else right?) for free
even though i offered him $30

thanks for your input - noise is luckily gone now

 

[Terminator03]

lol thanks for sharing. i know what you mean about not getting that section out while you were on the road...the mechanics were barely able to get mine out of there at the shop, but did and i threw it in back seat in case i choose to weld it back on by him down the road. i definitely thought aftermarket catback right away...but for the suv application (v6) ill consider welding it back on if its a lot less than a new catback. if its close ill get a new one!

Totally understand about saving when you can, especially if it’s not going to be a huge performance increase. In my case, it’s a V8, AND already had the headers, so I wanted to get it to sound a bit better. I also like duals, so when I learned of the TRD, I knew I had to find one (which wasn’t easy!). It isn’t true dual all the way, but looks and sounds awesome which was my goal, even if it doesn’t add power.

With regard to welding the tip back on, just know that is only going to be a temp fix. You may not even get a year out of it since you off road a lot. The issue is that the metal is very thin on the muffler housing, and once welded will lose the galvanize in that area so it will rust again quickly. My pipe was also very thin in JUST the area it broke, which was right at the back of the muffler, so I also would have had to sleeve the pipe, and possibly add a flange there to make it work, and that definitely wouldn’t have been worth the time, or money to me over just bolting in a replacement, even if just a stock. I’ve read on here that there are stainless versions of stock replacement ones, which I’d personally opt for even with a stock style replacement.

 

[hinmo24t]

Totally understand about saving when you can, especially if it’s not going to be a huge performance increase. In my case, it’s a V8, AND already had the headers, so I wanted to get it to sound a bit better. I also like duals, so when I learned of the TRD, I knew I had to find one (which wasn’t easy!). It isn’t true dual all the way, but looks and sounds awesome which was my goal, even if it doesn’t add power.

With regard to welding the tip back on, just know that is only going to be a temp fix. You may not even get a year out of it since you off road a lot. The issue is that the metal is very thin on the muffler housing, and once welded will lose the galvanize in that area so it will rust again quickly. My pipe was also very thin in JUST the area it broke, which was right at the back of the muffler, so I also would have had to sleeve the pipe, and possibly add a flange there to make it work, and that definitely wouldn’t have been worth the time, or money to me over just bolting in a replacement, even if just a stock. I’ve read on here that there are stainless versions of stock replacement ones, which I’d personally opt for even with a stock style replacement.

good info, appreciate it. i have a feeling ill be doing some research for a new exhaust...