rattling in engine compartment/drivers side wheel well

[infamousRNR]

Rattling in engine compartment or drivers side front wheel well???

anyone have this problem? sometimes i listen and it seems like a belt is squeaking and other times i get a big wind gust while driving down the highway and second guess myself thinking the metallic sounding rattle is coming from my drivers side wheel well....

funny thing is, I've noticed this on my 99 green 4runner when accelerating on the highway and in my new 02 silver 4runner when I'm going freeway speeds (65mph most prominent in both vehicles) and just have enough gas to the peddle where I'm just keeping my speed....


any guesses would be appreciated or stories of personal experience with this "rattling" type noise.

 

[bubbaleenc]

Water Pump?

I have heard the same thing you described in my 2001 T4R. I suspect in my case that my water pump bearings are wearing out. They aren't in critical condition yet, but on colder days under moderate acceleration I can hear the grinding rattle. It is subtle usually, but sometimes gets a little disconcerting. I'll be replacing the water pump with my timing belt relatively soon, so I'll repost if this fixes the issue.

 

[wake_rider]

I also had a pretty sustaining rattle in the same spot you're suggesting, but it was all of the time with any movement, including when the car was off and you shut the doors.

I got underneath the engine bay and had my wife shut the door multiple times until I found the source; the drivers side projector unit for the foglight needed to be retightened. The passenger side was loose by the slightest amount so I also tightened that up. I could still hear a slight but different rattle when shutting the hood and traced that to the a/c tube that runs immediately behind the grill. I tightened the clip that holds the tube to the radiator brace with some safety wire (the tube was very snug inside the clip, but the clip was rattling against the frame) and ALL rattles coming from the front end were fixed.

 

[TheDurk]

Maybe the ADD vacuum reservoir (essentially a tin can that lives inside the fender by the wheel well) has come loose from it's mounts.

 

[infamousRNR]

last time pump was changed?

I have heard the same thing you described in my 2001 T4R. I suspect in my case that my water pump bearings are wearing out. They aren't in critical condition yet, but on colder days under moderate acceleration I can hear the grinding rattle. It is subtle usually, but sometimes gets a little disconcerting. I'll be replacing the water pump with my timing belt relatively soon, so I'll repost if this fixes the issue.

do you approximately how long ago those items were replaced? over 70k or under 70k miles?

 

[infamousRNR]

reply

I also had a pretty sustaining rattle in the same spot you're suggesting, but it was all of the time with any movement, including when the car was off and you shut the doors.

I got underneath the engine bay and had my wife shut the door multiple times until I found the source; the drivers side projector unit for the foglight needed to be retightened. The passenger side was loose by the slightest amount so I also tightened that up. I could still hear a slight but different rattle when shutting the hood and traced that to the a/c tube that runs immediately behind the grill. I tightened the clip that holds the tube to the radiator brace with some safety wire (the tube was very snug inside the clip, but the clip was rattling against the frame) and ALL rattles coming from the front end were fixed.

question: you have a limited model with fog lights in the bumper valiance?

i will check those items however i only notice it while driving... thanks for the info! just seems strange its almost an identical sound in both of my 4runner's

 

[infamousRNR]

access to ADD vacuum reservoir?

Maybe the ADD vacuum reservoir (essentially a tin can that lives inside the fender by the wheel well) has come loose from it's mounts.

are there any write up's of how to access this item and verify that is the source ?

should i replaced it with a new one or just tighten down?

 

[bubbaleenc]

do you approximately how long ago those items were replaced? over 70k or under 70k miles?

Around 100k miles ago. I replaced the belt & pump around 100k a few years ago.

I've been hearing the rattle for 3 years now. About 50k miles. Every year the rattle gets worse. I think I got a bum pump, but it was out of warranty by the time it started making noise. Still no leaking so I'll let it rattle until I replace the belt & pump

 

[wake_rider]

question: you have a limited model with fog lights in the bumper valiance?

i will check those items however i only notice it while driving... thanks for the info! just seems strange its almost an identical sound in both of my 4runner's

Correct. The stock foglight bracket is pretty large in order to hold the sizeable projector unit. It's held in primarily by a single bolt, 10mm if I correctly recall. Tightening that up completely resolved the very obvious and elongated rattle.

 

[infamousRNR]

same sound in both 4runners

Correct. The stock foglight bracket is pretty large in order to hold the sizeable projector unit. It's held in primarily by a single bolt, 10mm if I correctly recall. Tightening that up completely resolved the very obvious and elongated rattle.

its interesting how this rattling sound is mostly at 65mph and the 99 4runner doesn't even have the fog lamps.

 

[wake_rider]

its interesting how this rattling sound is mostly at 65mph and the 99 4runner doesn't even have the fog lamps.

Ah, I didn't know that about the 99 Runner. I assumed it was similar to the 2000 Limited.

As for the speed, that seems to be a speed (65-75) that, for some reason, can often show some signs of worn parts and imbalance. I had terrible front-end wobble at that range whenever I first purchased my 2000 Limited, but a re-balance at a reputable shop with high speed/under load balancing completely resolved that wobble.


Also, that canister mentioned above is really easy to access. If you keep your wheels straight to slightly left, you can crawl under the front end (go from the very front, under the bumper) and then look towards the front lining of the drivers side wheel well; it is too obvious once you see it. There are two bolts on opposite sides of the canister that hold the bracket it's within to the wheel well. I'd give it some movement and see what happens. Mine was extremely solid/tight, so it would seem odd to me that it was loose, but it's worth a look.