Is it a problem when giving it a moderate amount of throttle?

If so it may the gas.

Just for kicks run a tank of Premium fuel and see if this helps. If it does you know you need to clean carbon off of the pistons somehow (like a Kreen Soak maybe).

As for your splash shield your timing chain didn't destroy that (or you wouldn't have an engine). It was likely damaged and your drive belt finished it off. I would install a new one so you don't get belt slip in hard rain (given its the passenger side).

 

As you suggest, change the PCV valve...the part at the dealer is under $6...just remove the black engine cover and you'll see it on the back side of the engine, sticking out just behind the oil filler hole...check the hose too...if the ends are brittle hard/cracking, change it too...

Another thought....the noise...it MIGHT be a broken engine mount called the "dogbone" (search here for more aobut it)...the one just to the left side of the engine by the drive chain cover...it's easy to replace if the rubber donuts inside the metal housing are cracked or worse...the broken mount can cause a physical rumbling/stumbling at lower RPMs that can be mistaken for a mechanical noise inside the engine.

Could be this? (check page 1 of this thread for pix of the dogbone and the cracks)

http://www.toyotanation.com/forum/1...h-generation-2002-2006-2007-2011/467441-cracked-engine-mount-aka-dogbone-2.html

I lost a dog bone/torque strut mount on my 02 a few days ago. I think losing a coil may have torn/damaged it. Will explain.

I peel back the rubber disks you guys are talking about to inspect the dog bone/torque strut mount occasionally, all looked good just a month ago. Last week on the highway the engine began to lose power, stumble, left me hobbling to the side of the highway. While trying to figure out what was wrong, I was watching the engine shake violently. The torn dog bone/torque strut mount was obvious, you could see the engine moving and the rubber torn. I started testing things, finally the coils, and that was the problem. Fortunate to have a spare in the trunk, would have gotten towed. Engine did not have enough poser to be on the highway.

So what I learned is if you want to test your dog bone have somebody put your car in D and with foot on the brake give it a little gas. You will see the engine torque a little and if the dog bone is shot it will be obvious, the engine will move and expose the tear.

Looks like if you do hole shots, stomp on it, torque the engine off a stop light, you can tear them. But...What I also noticed is the front engine mount down below plays a big role in preventing the engine from moving during acceleration, etc. So I'm wondering if a torn dog bone is a sign that the front mount needs to be replaced also. I suppose if I tear another dog bone soon that will answer the question.

 

Folks, I kindly appreciate the quick help! To answer your question, it IS when I give it a moderate amount of throttle. Today, I changed my oil (I use Mobil 1 5W-30 with a Wix Filter)

Today, I checked the PCV valve, and it appears to be functioning just fine. As for the 93 fuel, I'll try that on my next fill-up.

I also checked the dogbone mount, and it appears to be just fine as well. The only thing I found today was a small amount of black gunk at the top of the radiator resevoir. I also see a ring of the same black gunk in the overflow tank. I believe the radiator was flushed not too long ago, but it may be time for it again. Could this black gunk be the culprit?

I also failed to mention that the loud noise came on all of a sudden, and not necessarily over time. I also had a tune-up back in January, complete with a fuel system clean-up, which involved actually cleaning the injectors and what not (at least that's what my dealer told me).

Any other thoughts with this new information? Thanks folks!

 

Fuel injection service will not remove carbon from the pistons or combistion chamber. It is designed to clean the fuel line, fuel rail, and fuel injectors.

 

Thanks HT! Any guide or instruction on how to perform a Kreen soak of comparable way to clean these out? I have a Chilton's and I'm pretty savvy with this stuff, so I'm confident in attempting it myself. Thanks again!

 

Let us know how you went about using Kreen.

I saw the posts at bobistheoilguy, they talk about cranking the motor with the plugs off, which I understand. But what should one do with the plug wires? just leave them hanging on the side.... Since it's high voltage, I am concerned about arcing.

(on side note, why not do this "piston soak" with sea foam itself?)

 

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2335157

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2299099

 

Do you hear the noise just revving the engine while stopped? Check the foam at the intake manifold and see if it's soaked with coolant. Also do a "glove test" or exhaust gas test in the radiator. Check the water pump too.

 

Checking the foam at the intake manifold isn't something I've done before. How would I go about doing that? The noise is present while moving or stopped. Thanks!

 

Seafoam and MMO are different than Kreen. They are pale oil based and not as strong.

Kreen was designed primarily to remove carbon from I have read.

Also as for pulling the wires you probably mean coil packs which you would remove them completely and leave the holes open. When cranking the engine you would likely want a large towel over the holes to catch the product but not in the holes as to create pressure.

 

It's the black floating stuff in the coolant that made me wonder about check the head gasket.

Toyota put an insulation foam under the intake manifold, and if the head bolts come loose, the foam can block visible coolant leak when it's still small. See also: http://www.toyotanation.com/forum/1...generation-2002-2006-2007-2011/325124-gen5-2-4l-2az-fe-stripped-head-bolts.html

Can you locate the source of the noise? How's the oil and coolant level in the radiator when cold?