Slight grinding noise coming from engine. Shop cant diag

The noise never speeds up, it stays the same tempo. If I go down a hill (and we have a VERY LONG steep hill by my house, that you can get up to 60 mph on) I never hear the noise at all... ONLY when the gas peddle is pressed down. It's not a continuous noise, it appears around 2-2.5k RPM. Usually around 30 mph. But sometimes speed doesn't matter.

But like I said, the noise is only there when the gas peddle is pushed down. And If I hear it, I'll sometimes take my foot off the gas because I'm scared I'll break something, and the noise instantly stops.

The sound never "speeds up" it might get slightly louder depending how much pressure is on the engine

 

I reply with all that info above

 

UPDATE- had a mechanic look at it today. He said I need new catalytic converters.

Apparently the noise is caused by a build up if "pressure" or like air bubble so to speak? He said eventually the cats (or one of) will get clogged and mess up the engine. (Compared it to running a marathon and only being able to breath in not out)

Next questions

I thought there was people riding around with no cats at all? Is that something I could do? (Yes I'm being serious, I live in a state that doesn't test, and I am a BROKE college student)

If that's not an option, and I HAVE to put new ones on, could you tell me what ones I should buy off rock auto? Or could I just go to the junk yard and grab a pair from another sequoia/tundra?

Thanks

 

I'd expect a check engine light and a p420/p421 code constantly if your cats were really that bad. Sounds to me like he's trying to make a quick buck installing new cats in your truck.

If you remove the cats and don't get the ECU tuned for not having cats, the truck will not run well.

I'd talk to another mechanic before doing anything else.

 

And the mechanic said the cats caused the noise?

 

I’m calling bullshit

 

It does have a code P0430. And there's a ticking noise that means an exhaust leak ( I just thought since it was old it was making the tik tik tik noise)

But anyways, yes he's saying that the grinding metal noise ive been chasing is caused by my cats about to give out.

I Literally cannot afford to go to a second opinion.

What should my next step be from here

 

Gut the cats

 

This would be the first “grinding” cats noise reported here. It’s really hard to diagnose some problems long distance. There are no moving parts in a catalytic converter.

 

I've driven a car with clogged cats. It'll bog under full throttle, doesn't make any grinding noises. I'm not sure what the problem is, but that sounds like a shady mechanic trying to make a quick buck.

 

I tend to agree, but think the description is getting lost in translation.

mechanic should have got pressure figures from the O2 sensor ports.

desparate times call for desperate measures?

 

Damn this problem is really starting to get to my mental state. This is the second mechanic I've taken it to. First one couldn't figure it out. But this one I went to I've used before to install my water pump and timing belt. He's a Toyota tech for 10 years that works on the side for cheap. He did an amazing job last time and never tried to upsell... I'm not saying that's what's happening here, he might very well being going through his own financial crisis and just trying to make whatever money he can off me.

He said he was going to charge 2 hours of work and I bring the parts (that's him only making $150 bucks he charges 75 a hour)... If he was really trying to milk me why wouldn't he of done the timing belt water pump job that I was fully ready to pay for

Again I'm not defending him, I'm just simply looking for the truth and thinking out loud. Maybe there's a reason he no longer works for Toyota... He doesn't even work as a mechanic any more just simply does it on the side on the weekends. I mean he's a very smart guy, generally...

But again, looks can be deceiving and he may very well not have an answer to the problem and just said whatever the hell was easiest to just settle on. He spent less than 40 minutes diagnosing

This situation has already created enough trouble in my life. I just took a stupid ass title loan in order to pay for his diag and new parts . Now I'm having to wake up and go into work even earlier just to try and pay it back feeling like I'm about to pass out from exhaustion.

One thing is for sure, there is DEFINITELY a noise and it's playing cat & mouse

The only question is wtf do I do next. Guys I need help. . I'm really at a dead end in the road.

 

Putting aside the grinding noise, all that blue smoke (oil) you recently reported blowing out the exhaust could have clogged the cats.

The truth is that sometimes there's multiple problems with old vehicles that may or may not be related.

Best of luck.

 

How many miles on your Sequoia?
I listened to your video a bunch of times. Its certainly rotational and sounds tinny and hollow to me.
If you absolutely cannot reproduce it sitting in park and roving through the RPMs it's logically in the driveline, Transmission back to the rear wheels, or front wheels.
I'd start with a very close inspection of your drive shaft for rubs/bare clean metal. Take a look at the carrier bearing (drive shaft support, see pic) for failure.
You can have someone hold the brake (set parking brake as well) and put it in drive while you watch it from the side (NOT under vehicle!)
If uncertain about the amount movement you could post another video. Expect a small amount of driveshaft movement, but it shouldn't be a lot.
Check for any loose heat shielding while you are under there as well.
Carrier Bearing


Like @KNABORES said it could be a dust shield. Has anyone done any brake work/rotate tires/Did you hit anything/run over some brush, etc...? Here is a dust shield with the rotor off.
They are thin metal, and ride pretty close to the rotor and a small bend can make them rub and produce a very similar sound.


Just a few FREE things you can do to possibly find your grind.

 

It did sound a bit like a dust shield. And agree ot sounds like there are mutiple issues. You did mention a code.

 

While it's on my mind. I've watched several videos on YouTube, with plenty of comments backing it up, saying you can put a gallon of lacquer thinner into a half tank of gas, drive a continuous 150 miles and it will clean the cats out.

I know this may or may not solve my issue but will it clean my cats out so I can at least say I did it? Sounds like a cheap and easy way for peace of mind.

Now I'm no chemist, nor am I a mechanic but I am kind of scared to put lacquer thinner in my gas tank. Until I get confirmation by you guys first.


Also wanted to add, I've had 3 people ride in the car with me I ask them all the same question "where does the noise sound like it's coming to in relation to where you are sitting" and each one of them said it sounds like it's on the driver side. Now I know for a fact that car noises do a great job of throwing you off, we all thought my front driver rotor/brakes were scrapping. It ended up being the back driver. Just thought I'd throw that in there

 

Yeah had a sound that thought was front driver side ended up being right rear wheel bearing. Took a stethoscope for moving components to trace it with wheels off ground in drive. Had prior pulled pads from front rotors and spun by had to check for front wheel bearing noise to eliminate pad to disk sound from drag. Wanted those back in when doing the test with engine spinning the wheels in drive to be able to stop wheels ... and avoid putting in park until wheels are stopped ... becuase park pawl.

 

If your cats were actually clogged, when you floor it to get on the freeway, the engine would bog at high RPM. The exhaust gases can't flow fast enough through the cats and that bogs down the engine. Other trick is to pull both pre cat 02 sensors and see if it drives better. It's loud and will throw a check engine light. If you're not noticing any loss of power under full throttle, your cats are most likely fine.

Lacquer thinner won't clean out clogged cats, might damage other sensors, but most of the thinner is going to get burned off with the gas in the engine. The cats have a honeycomb that the exhaust gases go through and react with, they're not really a screen or something that can easily be cleaned out.

 

Is replacing both catalytic converters an easy DIY job for a girl? I'm thinking of just doing it myself, it looks like it's just unscrewing a few bolts and bolting up the new ones.

Edit- and I do know this may not fix my issue, I'm just kind of at a dead end right now, and can't afford "a second opinion" for $100 shop fee

 

The ease of replacing cats boils down to two things:

1. Whether or not the flange fasteners (studs/nuts) are rusted all to shit, and choose to come out easy
2. Whether you purchase a bolt-on solution for cats, i.e. no welding is required.

If you have a bolt-on solution that won't throw codes (there are tons of brands that'll cause you to throw codes), and the fasteners come right out, the biggest risk should be busting your knuckles getting to all the bolts. If you break a stud, bust a nut, or whatever, you're adding difficulty upon difficulty to the repair, because now you're drilling out and replacing studs on the flanges.

But shy of rust damage (i.e. cat totally rusts thru), the factory cats on these trucks simply DO NOT go bad. To the point that, if I personally had a truck with holes in the cats, I'd try to find a way to sleeve the cat rather than even think twice about replacing it. They're too fucking expensive, the aftermarket is too flaky, and I wouldn't want to need to deal with a broken stud.

Total bullshit.

Peace of mind for what, exactly?

As you should be, it's fucking stupid, I give you props for recognizing that much.

Sounds like you may have a loose cat heat shield then, maybe? If you think it's around the cats at least...

 

Cats are expensive and the bolts are most likely rusted. Most of us on here are also telling you that cats going bad don't make any noises like that. After going back and reading through the whole thread again, I'm going to agree with others that have said it's probably something on your serpentine belt. Easy way to check is to remove the belt and drive around the block and see if you hear anything. You can also eliminate it as a problem by doing that.

 

What symptoms do you have besides the noise?

 

Lacquer thinner would he horrible in the fuel system and it would cause a lot of damage to the fuel lines by drying them out.

Anything rubber or plastic would be degraded badly.

I've never heard of anyone putting that in their fuel tank before. Pure snake oil except this snake oil is harmful.

 

No other symptoms besides the noise. It seems to be getting a bit louder as the days go by (that might be my head just messing with me). I mean honestly the sequoia drives great AFAIK

And to the other guy, how do I go about removing my serp belt without messing anything up? I thought driving without the serp would mess up something on the truck? (Even if it's something minor in scared to take chances)
It looks like I will need to
1- take the fan pulley off
2- release the tensioner in the opposite direction that normal bolts come off
3- remove belt
4-put fan back on
5- go on a drive like normal
6-install in reverse order

Does that sound about right? I'm a absolute beginner, and a not very strong girl, anything else I should know about?

 

Shouldn’t have to remove the fan

 

Ok - so you’re a poor college student or whatever. Post what city you in and maybe a fellow member can come to your assistance.

 

It looks like to me that the only part keeping the belt from coming completely out of the engine is the fact that the big fan is keeping it from being pulled directly up and out (I'm probably looking at it wrong)
This is a 2002. The big ars fan connects right to the water pump.

In Birmingham Al. I posted on a complete different part of the site and never got much attention.
Should I just go ahead and pony up the extra $100 for that 2nd opinion? Am I really out of options

 

Once the belt is off the pulley system, you can pull it around the front of the fan to remove it.

 

Could not reproduce when parked revving engine
1st post
"I tried to make it appear with the truck in park, and foot pressing the gas peddle at different RPMS, didn't make the noise."

 

What is your attached file supposed to be? It's blank