Need Help! Weird Noise when coasting!! (long)

http://static.photobucket.com/playe...ms/yy68/EddieCorcoran/VID_20110307_194052.mp4


Hey guys my name is Eddie. In december I bought A 2002 reg cab tacoma and the truck has been great to us so far. About 2 months ago I took it to big bear in the snow (around 7,000 feet) and thats when I heard the noise for the first time. It happened right after I used the truck to plow the berm of my parents house in 4L. GREAT 4WD!

The Noise only happens when i'm coasting or just letting off the accelerator. The noise only happens when the truck is MOVING. The noise goes away a couple seconds after touching the brakes. It sounds like an airy squeel, or shreak. It's high pitched and also sounds a little grindy. Very weird noise.

my girlfriend says that it it sounds like a wagon with a bent axel, only louder and faster.... the noise is not consistent with vehicle speed or RPM...

The noise is the ONLY symptom. The truck drives just fine and no lights illuminate.

So for the rest of our vacation in big bear (after plowing the driveway) the truck made the noise EVERYWHERE we went when we were up there. I called my local mechanic in Los Angeles and after describing the noise he gave me the go ahead to drive it to him instead of getting it towed over 100 miles. But then, for some reason, as we were heading down the hill the noise stopped!

I took it to the mechanic in LA and he couldn't find anything! And the noise never came back until.... we went back to big bear in the snow a month later! We drove into town at night and the truck started making the noise again (while coasting). It did it while the engine was nice and hot over an hour into our drive and didn't stop until we reached my parents place. That night I made an appointment to take it to a mechanic in big bear the next morning.

So the next morning I'm driving the truck to the mechanic and the truck makes the noise the whole way there. Then the mechanic jumps in with me and of course the noise just stopped. We tried going on test drives 3 times that day and the noise never came back. I drove the truck that night and the noise never came back. The next morning, I drive the truck, and it makes the noise! So I head straight for the mechanic again and it stops as soon as I get within a block of the place. 3 test drives at different times that day... NOTHING.

So we drive the truck off the hill again and the noise goes away... another month goes by and the truck made the noise for about 2 seconds after I had driven the truck an hour earlier... This was in the middle of the day in about 70 degree weather.

Another week with no noise...

Then tonight... the truck made the noise the whole drive home! Around 25 min drive. we went from about 1400' to 500' on the drive and the temp went from about 40 degrees up to 50 on tonights drive.

At first I thought it must be releated to altitude, seeing that it only made the noise in big bear (7000')... but now I'm thinking its more related to cold ambient temperatures.... the only thing that throws me off is the time it did if for a split second in 70 degree weather...


I'm stumped.... two mechanics are stumped.... everyone else who has actually heard the noise is stumped... so now I'm counting on you guys!


Thanks to anyone who can lead me to solving the "phantom noise"!! You guys rock!

Thanks!

Eddie


T

 

what's hilarious is that I went through this EXACT same situation. LOL.

I drove all the way to wyoming in a winter blizzard (CA TO WY). I heard the noise after driving in 4x4 on backroads for about an hour when it was ~ -20 outside. I can only describe it as being exactly what you said. Sounded like it was coming from the front wheels. I took it to a local mechanic the next day - couldnt find anything wrong with it.

So I drove back to CA - noise was present during the drive home from WY to southern Utah...but it is very random and stopped once I stopped the vehicle. Once I was back in warmer weather I never had the noise again.

To this day I have never figured it out. I laughed when I saw this thread because it was like I was reading something I wrote myself. As far as the noise goes: the only thing I can think of is some sort of ice buildup on the front suspension. When you let off the gas the front suspension relaxes slightly. At least you are only getting the mysterious noise during the cold. It was so cold up there that my CEL came on when I was driving over the mountains in the blizzard near my families ranch. It was about -15 outside with 40-50mph winds. The CEL indicated that the cat was not functioning properly (which will only happen during EXTREMELY cold scenarios).

Long story short - it clearly has to do with the cold, I wouldnt sweat it too much. This happened to me ~10k miles ago and I have no probs at all.

 

is it a squealing type noise?

if so I would bet money on it being a loose heatshield...

crawl under your truck and tighten ALL the bolts on the exhaust heatshields...above the cat, behind the cat, etc, etc...

they wont tighten much, but it will be enough to make it go away...

just fyi i think the heatshield directly above the cat (its a really long heat shield) is the one on my truck that was loose good place to start...you can grab the heatshield and pull on it...of course the thin metal will flex, but if you can reposition it then it obviously squealing from all the road vibration...

oh and if you get back in the truck and it makes the noise less, but not gone, I'd say you've found the problem and now you just need to keep working at it...but if it doesnt change a thing hopefully someone more knowledgable than me will chime in!

 

Aw man! I started reading your post and was like YES!!! this guy had the same problem! Well the noise is starting to happen more and more... hopefully I can find the problem soon! Seems to happen more in cold... so at least I know its not just me! You said your noise came more from the front. I forgot to say that when I was in big bear, I had my girlfriend drive the truck and I hopped in the bed... I leaned over the sides and the noise seemed like it was coming from right under the cab.... Also from inside the cab it sounds like its coming from under the seat.

There ya go! Yes! very squeely! But kinda loud! This sounds like a good place to start. Very consistent with where I THOUGHT the noise was coming from... I'll have tro crawl under there when I get home and tighten everything up! I'll post back here with results! I could also see tapping an exhaust shield loose as I was plowing the berm at my parents house... Im sure the truck bottomed out somewhere in the snow... Hopefully this is the fix! I know where the cat is on this truck... so im sure i could find them... but just incase, what type of metal are the heat shields made of? color? Just incase I have a hard time finding them =] New truck.. Gotta learn the new layout!

 

okay so I found 3 heat shields. They all seemed to be on there very tight, but I got probably about a quarter of a turn on the bolts on the heat shield over the muffler... the two others were on there very well, but I still got the bolts to move a little when I went to tighten them...

here is the one over the muffler:


and the other two just before, and over the cat.


then I started testing every bolt I could find and came across a missing bolt on the skid-plate under the gas tank... I hit the loose part and it sounded like more of a rattle... not the squealing like I heard before... could be unrelated... but I'll order the bolt anyway.




the only thing is that the other 3 bolts are on the skid plate just fine... and the hole doesn't line up where the bolt is missing...



I'll take the plate off and try to get it to line up but for now I'm not going to touch it until I get a chance to drive it to see if the heat shield fixes my problem! If it still persists the gas tank is next!

 

I have the same thing going on in an 04, same deal. Its a squeal that happens 25mph and above.
I thought mine may be the carrier bearing, or the rear diff, the axle, bearings, etc. I still think mine is messed up brake squealers. My brakes have enough wear left.
Check your rear wheels, cables will go to the back of the drums, where a bolt taps the drum. Is that where the sounds coming from? test it. slide a piece of cardboard inbetween it. then drive it. The bolt just above the springs
I will get a pic. Its ok to laugh me off the board, if I'm newbie.

 

Bump! Video of truck making the noise added!!

The heat shields didn't fix it.... please help!

I'm in big bear now.... it just made the noise for the last 45 min of our 2.5 hr drive.

Thanks guys!

http://static.photobucket.com/playe...ms/yy68/EddieCorcoran/VID_20110307_194052.mp4

 

I have not fixed mine either. I'm starting to believe its the e-brake, it looks like thats a Tacoma issue if you look it up. Did you look where my picture was taken. I'm confident mine is e-brake related.

 

I have a similar issue with noise coming from the truck, which goes away when I use the brakes. In my case and may be yours, I think (like BrianLV) that it is the e brake squealing. I am going to try and fix this myself this weekend and will let you know if it takes care of the problem for me. Basically, I think the e brake is hanging on the rear drums and causing a squealing/grinding/metalic noise that stops as soon as I hit the brakes.

In your case, it may be different but it also may be that the cold and snow impacts the action of the e brake bell cranks on the rear drums and causes it to hang up. When it warms up it fully releases and then you no longer hear the noise. Might be complete crap but I will let you know if I can fix mine.

 

I'm having a very similar problem on my 2004 Tacoma. It started a couple of years ago, and after my mechanic tightened my belts it went away for a little while (or it just got warmer, I can't remember). It only happens when its cold out, and I'm traveling over 40 or so. The sounds goes away when I accelerate, but continues when I'm coasting or just lightly hitting the gas. I recently had my belts replaced(I just reached 115K with my original belts), and everything appears very tight. I brought it to my mechanic and he can't seem to locate the issue. I've posted audio of the sound on Youtube

http://www.youtube.com/watch?v=mmgNW3u5sTc

This other post on the forum describes my exact problem as well.
http://www.tacomaworld.com/forum/4-cylinder/73466-unidentified-noise-98-prerunner.html

Any help would really be appreciated! It doesn't seem like anyone has pinpointed the problem here on the forums yet. Thanks

 

Hey there! Its funny you bumped this thread. I was about to report back for everyone next week when we go to the mountains. So we kept driving the truck, and the noise started happening more and more. It wound up being bad axle bearings. They were making the god awful noise we kept hearing. We had checked the carrier bearing, the wheel bearings, and also replaced all our belts and water pump before finding the actual issue. Belts and waterpump was on the to do list anyway, so I wasnt mad about that, but I was hopeful in thinking it could be the water pump bearing.

SO ya, BEARINGS. Check them all. Your noise sounds very similar to mine.

I have not taken the truck back to the mountains since replacing the axle bearings, but the noise has completely gone away. I will, however, report back here after my trip but I am pretty darn sure we got it this time.

 

Thank you!! I will check them all, and hopefully I will have something good to report back to everyone soon!

 

I know this old thread, but my 15 tacoma is making the same sounds as you are describing.. any updates after 4 years?