Terrible noise has me baffled

[Outrider]

Specifics: '99 V6 2WD, automatic, 130k miles

When the engine is under load, from 2k rpm upwards, there is a real "resonance" that I can hear and feel. Power feels normal, though. When I pop the hood, and rev it up with the throttle arm, I can't hear or feel anything. It's only under normal driving load. When I put it in neutral while going down the road and rev it up, it sounds normal. It definitely sounds like it's coming from the engine compartment, but I can't tell from which side. Problem used to be intermittent, but seems to be constant now.

While pondering what it may be, I discovered other things that needed done anyway. Replaced the trans. fluid, and all 3 drive belts. With the drive belts off, I felt the alternator, water pump, power steering pump and a/c compressor. All bearings felt fine, but there was the tiniest amount of play in the water pump shaft. Fan clutch will turn by hand, but has pretty heavy resistance. Timing belt was replaced when the previous owner had it, by a dealer, at 97k miles, so I presume the water pump was replaced then, too.

I don't let anyone touch my vehicles, except for tires and alignments. But I am pretty close to taking this to a Toyota stealership and ask them to find the problem. I bet a technician would be able to drive it and identify the problem, from past experience. But once they tell me the problem, I'd probably say that I'll fix it myself. I'm unemployed, and don't have much money at all to pay for wrenching labor.

Before I take it there, does anyone have any ideas of what may be a common problem?

 

[quicksilvr]

Specifics: '99 V6 2WD, automatic, 130k miles

When the engine is under load, from 2k rpm upwards, there is a real "resonance" that I can hear and feel. Power feels normal, though. When I pop the hood, and rev it up with the throttle arm, I can't hear or feel anything. It's only under normal driving load. When I put it in neutral while going down the road and rev it up, it sounds normal. It definitely sounds like it's coming from the engine compartment, but I can't tell from which side. Problem used to be intermittent, but seems to be constant now.

While pondering what it may be, I discovered other things that needed done anyway. Replaced the trans. fluid, and all 3 drive belts. With the drive belts off, I felt the alternator, water pump, power steering pump and a/c compressor. All bearings felt fine, but there was the tiniest amount of play in the water pump shaft. Fan clutch will turn by hand, but has pretty heavy resistance. Timing belt was replaced when the previous owner had it, by a dealer, at 97k miles, so I presume the water pump was replaced then, too.

I don't let anyone touch my vehicles, except for tires and alignments. But I am pretty close to taking this to a Toyota stealership and ask them to find the problem. I bet a technician would be able to drive it and identify the problem, from past experience. But once they tell me the problem, I'd probably say that I'll fix it myself. I'm unemployed, and don't have much money at all to pay for wrenching labor.

Before I take it there, does anyone have any ideas of what may be a common problem?

I don't have any suggestions, but wanted to say that I experience the same thing (I think) in my '99. It sounds and feels like the engine isn't balanced well, or something is "binding", or the exhaust has a horrible resonance. However, the power feels normal, like you say. It's almost like upwards of 2k rpm I feel like I"m hurting the engine. And I've driven 5-6 different 3rd gen 4runners with the 3.4, so I know what I experience with mine isn't quite normal. I'm used to it now, but I know the very first time I drove it when I purchased it, I noticed how it felt and sounded different than I expected. Like it was being forced to do something it didn't really want to do.

I bet if you take it to a technician at Toyota, they won't think there is anything wrong. But you can always try.

 

[Outrider]

Yeah, your description sounds exactly like mine does. I bought this thing 3 years ago with 106k miles. It has been absolutely trouble-free until now. It literally was owned since new by a little ol' lady who pampered it and took it to the dealer every 3k miles. It came with all maintenance records.

I really love the vehicle, but this problem is driving me out of my mind. You're probably right about what a dealer would say. I'd hate to blow money just to be told that.

Thing is, I'm close to taking it on a 6 hour road trip. I'm skeered to, but if yours has been doing that for a while, maybe mine might actually make it there and back. It's just the thought of a huge tow bill for 300 miles that really scares me.

 

[BTO]

You are free to throw your money around how you like but if I were you (I know what it's like to be unemployed) I'd save my money and live with some noise for now. At least until you get a job. Check the normal stuff yourself.

 

[quicksilvr]

Yeah, your description sounds exactly like mine does. I bought this thing 3 years ago with 106k miles. It has been absolutely trouble-free until now. It literally was owned since new by a little ol' lady who pampered it and took it to the dealer every 3k miles. It came with all maintenance records.

I really love the vehicle, but this problem is driving me out of my mind. You're probably right about what a dealer would say. I'd hate to blow money just to be told that.

Thing is, I'm close to taking it on a 6 hour road trip. I'm skeered to, but if yours has been doing that for a while, maybe mine might actually make it there and back. It's just the thought of a huge tow bill for 300 miles that really scares me.

I just drove mine 1800 miles (29 hours) across the midwest and through Colorado. Over 12,000ft mountain passes and everything. Drive it.

I figure if there is actually a problem, it'll show up somehow at some point. Right now, I think it's an exhaust resonance thing since I have Cali spec truck with 2 cats.

 

[Outrider]

Yeah, I have actually been hoping that whatever is making the noise would just go ahead and break. That way, I could find what it is. I have thought of everything that comes to mind, and I have been working on cars myself for 30 years now.

I feel a little better, and will go ahead and just drive it.

But hopefully, someone else has gone through this, found and fixed the problem. It goes against my grain to live with terrible noises, unless I at least know exactly what it is. Had a '95 Pathfinder once, and the throwout bearing squealed for 5 years. But at least I knew what it was, and it never went out on me.

 

[02SE]

Trying to diagnose a noise without hearing it, is not easy. Can you guys make a recording of the noise(s) you're experiencing, and post it?

Just from the descriptions, I'll guess a loose exhaust heat shield somewhere. Or maybe the exhaust hanger rubbers have deteriorated enough that the exhaust pipe is hanging down enough to periodically contact the frame crossmember located above the rear axle, that the exhaust system is routed up and over.

 

[quicksilvr]

Mine's not loud enough to hear with a recording. It would just sound like a normal engine. It's more the combination of feeling/hearing it when you're driving....and being mechanically inclined and tuned in to what is normal. I non-car person would probably never notice mine. I've just driven and worked on so many vehicles in my life, I notice it.

I think it's either an exhaust resonance that cannot be changed, or an engine balance issue. Which again....cannot be changed without a complete rebuild.

 

[Outrider]

Same here on recording the sound.

But I will look at the exhaust manifold, heat shield and hangers. That most certainly sounds like a possibility.

 

[Outrider]

Well, just an update. The mystery lives on. It's not the rubber pipe hangers. They look good, and I get no rattles when I grab the pipe and shake it. Exhaust manifold shields look good and I get no rattles from them when I wiggle them.

So, it's probably either exhaust manifold bolts (been there/done that on my old Pathfinder), or maybe something else. I sure hope it's not something inside the engine doing this.

 

[ReconCmdr]

I had a very similar sound. I put my truck up on a rack and greased the uv joints and it went away completely. The uv joints on these have grease fittings and are never greased for some reason when taken in for regular maintenance. As soon as I drove mine after greasing them it was perfectly silent.

Just another idea for you to look at.

 

[Outrider]

I had a very similar sound. I put my truck up on a rack and greased the uv joints and it went away completely. The uv joints on these have grease fittings and are never greased for some reason when taken in for regular maintenance. As soon as I drove mine after greasing them it was perfectly silent.

Just another idea for you to look at.

Aha, yes that is definitely a possibility, but it sure does sound like it's coming from the engine compartment. I will do that tomorrow. As with some of the other things I've run across, it needs done anyway. If it solves the problem too, then it's both gravy and then ice cream for desert.

 

[rajuncajun]

I was gonna say that I have the same problem and I'm quite sure that it's worn u joints. That's a great find. Hopefully that fixes your problem.

As far as something being off balance in your engine compartment to vibrate there isn't much that would last vibrating like that without failing.

My next thought would be maybe a wheel bearing.

 

[Outrider]

Yep, I did suspect a wheel bearing, but I felt all 4 mags after a 30 minute trip, but nothing was even more than lukewarm. Still a possibility, though. And yep on the engine. Never know of a Toyota engine that would grenade at 130k miles, and I have owned a few of them.

Ok, I can't wait until tomorrow to grease the u-joints. Gonna go down there right now and break out the grease gun. Tomorrow morning, I'll take it out for a spin, and update this topic with the results. I do have a pretty good gut feeling about this, and I'm rarely wrong about gut feelings.

Regardless, it needs to be done anyway, and thanks for the info, ReconCmdr.

 

[BigFishAllDay]

I had a very similar sound. I put my truck up on a rack and greased the uv joints and it went away completely. The uv joints on these have grease fittings and are never greased for some reason when taken in for regular maintenance. As soon as I drove mine after greasing them it was perfectly silent.

Just another idea for you to look at.

I think this is probably the best suggestion yet.

Beyond that, with the details you've provided I can't give you much help except to say that on my '97, sometimes when I'm just cruising on the freeway 70-80 mph, it gets into this mode where I get something similar.

It's like I'm going down the road and I can hear (and feel) this whhhhhhhhooomp, whhhhhhhhhhhhhomp, whhhhhhhhhhhhhomp... very rhythmic vibration. It starts at a low frequency, goes high frequency real quick and repeats.... after awhile it stops.

I chalk it up to old age. The truck is 14 years old. Cars are like dogs, at 10 years, they're old and they show it.

All I know is it's a 4Runner, and it's a Toyota, so don't be too picky or too much of a perfectionist. It's gonna have quirks, but one thing I can almost guarantee you is that whatever it is, it is not going to leave you stranded. When it breaks, it will START to break and you'll know it. You'll get home, get it fixed, and move on. Turn the radio up. :guitar2:

 

[Outrider]

Well, no dice on the u-joints. There are not grease fittings on either end, as my Haynes manual shows. Unless someone can suggest a secret way of greasing these, the only way to hope for a solution is to buy a whole new drive shaft. Sure, I can get light oil into the u-joint bearings, but they need grease, not oil.

 

[02SE]

The 2wd 4runners used sealed u-joints. They are pretty easy to replace if they are bad.

 

[Outrider]

The 2wd 4runners used sealed u-joints. They are pretty easy to replace if they are bad.

They sure look like an integral part of the driveshaft. I don't see any way to just unbolt the u-joints, except for just unbolting each end of the shaft, with the u-joints still attached to each end. What am I missing here?

 

[ReconCmdr]

Mine is 4wd so its hard to tell what you can do. My U joints are rather easy to take out and replace. I was about to do that if the greasing did not work. I have to think that they would be just as easy on a two wheel drive...?!?! I hope you get it figured out. Mine drove me nuts and I swore it was the engine. Thank God it was not.

 

[Outrider]

Well, some more research shows that I can buy two new u-joints for around $20 each. Pull the whole shaft out, press out the bearings in a vise, and press in new ones. Really, not that bad of a job, or very expensive, but definitely not a simple wrench job.

Anyone else ever done this?