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Hi all,

I just picked up a 1996 4-door automatic AWD Rav with 205,000 miles on the clock. Normally I'm more wary of high mileage engines, but this is only a two-owner vehicle and the owner I bough it from had all of the service info.

I'm making this post because I'm concerned about some noises it's making and want to get some input on what you guys might think it is.

The first and most worrying noise I'm getting is a buzz at a specific RPM under light acceleration. When taking off from a stop, around 1800 RPM, there is a noise I can only describe as a buzz coming from the front of the car. If I hold the engine there it seems to get a touch louder then doesn't change. It seems to be the same in any gear. Any idea what this might be? I was up under the car, since I searched the forums and found a lot of posts about exhaust heat shields making noise. Under the car there was an old exhaust clamp that was a bit loose, so I tightened it down, that doesn't seem to have made a difference. Should I start checking underneath the exhaust manifold cover?

The second noise I'm hearing is a whine or hum while the car is moving. It's directly related to engine RPM, if I left off the gas it goes away.

My concern is that there may be something on its way out in the transmission, maybe the torque converter? There was a thin wetness of oil on the underside of the car, but not enough to puddle or drip at all. I've checked the transmission fluid with the car hot and it was dead in the middle of the HOT section.

I'm pretty handy with car work, but I'd rather have somebody else drop the transmission if it needs to be done. I just wanted to hear your thoughts before taking it somewhere and maybe get some other ideas.

Thanks for the input, hopefully you'll see more posts from me as I get more acquainted with the car!
 

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Check/ replace all the fluids, and change the filters. Don't forget the transfer case's fluid (dipstick/fill tube is behind the right front tire, down low). AWD uses a different trans fluid than FWD.

If you can post a great video/audio of the noises, that could help.
 

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Discussion Starter #3
Check/ replace all the fluids, and change the filters. Don't forget the transfer case's fluid (dipstick/fill tube is behind the right front tire, down low). AWD uses a different trans fluid than FWD.

If you can post a great video/audio of the noises, that could help.
Thanks LugNut, I'll see if I can't get a video of the noise. I'll also try going through all of the fluids and filters to see if it makes a difference.
 

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Good! Those are routine maintenance items anyway.

Lots more of those too, unless you know for sure they have been done. E.g., plugs, wires, cap and rotor, upstream O2 sensor, air and underhood fuel filter, PCV valve, timing kit, water pump, thermostat, antifreeze, serpentine belt, ... and that's just the engine! :) {RockAuto, but avoid the cheapo parts.}

If you have some blue exhaust smoke at startup, especially after it sits overnight, etc., then the valve stem seals haven't been done yet. Proactvely replace the EGR's VSV, and the belt kit, pump, ..., at that time if the head is coming off to do the seals.

And get a (cheap) OBD-II code scanner, if you don't have one already, and use it! {U.S. 1996s have OBD-II?}
 

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Yup, I'm already putting together a Rockauto parts list of things to do now that I have the car. So far I'm looking at ngk plugs/wires, a new dist cap and rotor, filter and gasket for transaxle, and any other tune-up items.

Air filter got changed the day I got the car, as the old one was pretty dirty.

The timing belt job was last done at 175k and included the water pump, seals, and everything else that goes in there from what I saw on the invoice. What is the interval on the timing job, 60,000?

No blue smoke at startup, not that I've been able to see. My only concerns right now are the little clunks, rattles, and buzzes the car occasionally makes. As always, I'm paranoid for the first month or so when buying a used car. Other than the goofy noises, the interior is in fantastic condition, (only thing I've found is a scratch on the glovebox) including the original radio and cd deck! The exterior is pretty good for a 25 year-old car in a climate that gets snowy. A patch of rust on the passenger rear wheel-well, but underside of the car looks great.

Yup, we got OBD-II in 1992 I believe. So this one has it. No CEL, or any other lights for that matter. I had the brake light come on for a minute one day, but the reservoir sensor wire was just a touch loose.

I bought this rav4 as a winter car, as my '86 300zx isn't exactly snow friendly. So initially I was planning on only doing the bare minimum for maintenance to keep it running, but the car is growing on me fast and I'm finding myself wanting to keep it for a while longer than my initial plan of a couple years. We'll see how that goes, lol.
 

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In my experience with low rpm buzz noise on this type of engine has been timing belt tension not set correctly. It is pretty easy to pull the upper cover and check tension, but if you are handy and plan on keeping the car, I would do the timing belt service.
 

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-- Does the CEL come on briefly during the lamp check (with the key turned from the off position to the "on" position, but not the "start" position)?

-- I would put all four wheels on jack stands; get a hollow metal pipe to use as a stethoscope; get a friend at the wheel who starts the Rav with the Rav in neutral and holds the Rav's engine steady at a few different RPM; and, with safety in mind given the moving parts, try to narrow down the source of the buzzing with the stethoscope. I'd be paying particular attention to the alternator shaft bearing(s); the distributor's shaft's bearing(s); and the timing belt cover area. If my sense was that the buzzing is coming from under the timing belt cover, then I would loosen the upper timing cover's bolts and pry on it a bit to see if the buzzing becomes more pronounced.

-- If the buzzing appears to sound more like hissing, I would be checking the vacuum tubes with a smoke test. Then again if there were a vacuum leak, I would suspect you would notice at least some small engine performance problems.

-- If you think the buzzing is coming from the exhaust manifold (as in a blown gasket?), then I would go ahead and remove the four 12mm bolts holding the exhaust manifold cover in place and remove it. Then I would do my stethoscope checks with the vehicle running.
 

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the original radio and cd deck!
If it still has the stock speakers in the doors and rear, you'll be pleasantly surprised what a cheap/easy (except for pulling the panels) speaker upgrade will sound like. I had done a thread or two on such, long ago with lots of pictures, but it/they may have been lost when this site went away for a year or so. LMK.
 

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These cars are a bit noisy and buzzy, especially as they age. They weren't real quiet to start with and had plenty of NVH (noise, vibration, and harshness). It is part of the car's character and charm. The care might be fine as is. With mine, I can find a few specific sources of vibration at certain engine RPMs if the engine speed is held steady just right to bring out a resonance.

One is that the hood itself can vibrate a little. There are two rubber bumpers at the front corners that can apply some upward pressure and are adjustable, but in my case, are just a bit too small. I might try buying some at Toyota to see if maybe mine have shrunk but they look ok. I suspect that previous owner's accident damage repairs has left things very slightly out of shape.

The front license plate will vibrate at certain times which can buzz or hum. Adding a frame or maybe putting some larger washers on the mounting bolts might help.

Various exhaust parts, particularly the shields vibrate even if undamaged.

Also check the accessory drive belt tensions that they are correct. If too loose, the loose side of the belt can flap which makes can make a hum. If too tight, it is hard on bearings and can make a whine.
 

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Recently had a similar issue at around 3k RPM. Check the timing belt as @Elle said for sure and see if the belts/harmonic balancer are flapping around when the engine is running (wheels turned all the way to the right, splash guard removed).
 

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Discussion Starter #11
Hey everyone, I apologize for the late response. Busy weekend! I got the chance to crawl all the way underneath the car today and was able to find the source of the problem, which I'll detail below for anyone who finds this thread later on. I want to thank everyone for their responses to my initial questions, they are greatly appreciated!

Without further ado, here is what I found, the smoking gun as it were. Turns out it was definitely the heat shields making that racket. Video below:


Here's some pictures of what I ended up removing from the car:
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159478


Looks like at some point a ~2 foot section of this heat shield rotted away and somebody tried to use hose clamps to hold the remaining pieces on. I did some reading around and it sounds like it's mostly agreed that they aren't terribly important in cooler climates, so I decided to do away with them. The car is now fantastically quiet, just the engine noise now, and even that is pretty quiet. I hadn't seen these when I first went under the car as they were a bit farther under than I went.

Tom1997:
  • Thanks for the tip, should I have noise come up again I'll look into it. I plan on doing the timing belt service once it comes up.
Elle_rav4:
  • Yup, all the lights come on before starting the engine, then go away once it's started. I checked that before shaking hands on the purchase!
  • Did some more looking around and I'm not hearing any other odd noises after removing these shields, thanks for the tips though. I'll come back to them should I ever have other odd noises.
Lugnut:
  • Thanks for the tip! I'm actually pleasantly surprised the speakers are as good as they are now, only complaint I have is a bit of buzzing if I turn the bass up some. I usually leave it in the middle, so not a big deal. If I ever look at replacing them I might ask you for that write-up!
cRAVe:
  • I noticed that vibration in the hood, it's pretty quiet now so I think I'll leave well-enough alone. Can't hear it unless you get right up in front of the car.
  • I went through and checked the belt tensions while I was at it, all seems to be in order. No room for wiggling around.
let_us_rav(e):
  • Thanks for second on Elle's suggestion. I'll keep an eye out for it, I think all is good for now.

Huge thanks to everyone for chiming in on the issue I was having. Now that my mind is clear of paranoia that something was frighteningly amiss, I can move on to the fun stuff! Like finding a roof rack and tire cover, which according to the dealer window sticker I got came with the car but are gone now :confused:. Also, are there some good write-ups around on how to clean up the wheels, they're pretty roughed up from our winter saltings and I'd like to see what I can do clean them up a bit.

And for my next post: FS: Exhaust Shields, Lightly Used!

Any takers? ;)
 

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If these wheels' rims are alloy, then I found that a mixture of pure vinegar and liquid dish soap (no water) applied with #0000 fine steel wool cleaned them up really nice. This required hardly any elbow grease. I cleaned the wheels with them off the vehicle, so I could keep the vinegar off the tire rubber as much as possible. I did a thorough rinse with water afterwards.

Lightly used -- funny :)
 

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only complaint I have is a bit of buzzing if I turn the bass up some.
This is something I was able to repair on the factory speakers in my Rav4. The front speakers would buzz on any strong bass. Around the outside of the cone, where the speaker surround meets the basket (speaker frame), there is a ring of fibrous material, like very dense cardboard. This had delaminated a little causing vibration on bass notes. I was able to glue it back down using Permatex 5-minute epoxy, then letting it cure overnight with some weight on it. The front speakers are good as new now.

The rear speakers, I'm going to leave for now since they are too hard to get to and I'll probably break a number of brittle, old, and expensive plastic clips in the process.
 
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