1. What do you think the noise is?
2. What else should I plan on replacing while I’m in here?
(I’m replacing my timing cover gasket (tiny ext leak), head gasket (coolant odor in exhaust), and probably timing chains (175k) and hopefully determine and remedy this noise. Machining heads and maybe rebuilt as warranted ($275 and $450/pair respectively))

I’ve got a 3 week window to borrow a vehicle and need to get parts ordered and anticipate my outcomes. Here’s what I’ve got.

• Loud clattering in the engine when I’m in gear—D, 3, 2, 1, even R. It does not make the sound in Park or Neutral. (Maybe it does, but it is obviously a different tone or subtle—I’m tone deaf.)
• It changes speed with the RPM. Loudness does not change.
• Does it cold, warm or hot. (Weather too.) Loudness does not change.
• I cannot narrow it down to one bank or the other.

Background summary (detail in prior thread):
Last year I blew out a spark plug and burned up the coil pack driving down the highway (driver side closest to fire wall… forget the numbers)—loud clattering (similar but much more chaotic and loud) and sudden loss of compression. Had it towed. Mechanic retapped and cleaned out, set the plug and new coil pack.

It was making the clattering noise when I picked it up—asked the mechanic and he said it’s just lifter noise, don’t worry about it. It is louder than any lifter noise I’ve ever compared to—my kids hate me picking them up and dropping them off b’c it’s noticeable and obnoxious!

I actually had IMPROVED power/pepp (which I didn’t realize was a little sluggish) after I picked it up.

As far as I can tell the sound hasn’t changed over the last year. (Maybe it’s progressed but if so it’s been gradual so I can’t compare.)

I measured the lash on the lifters 3x (both sides) when changing my valve cover gaskets earlier this year. All in spec (some borderline but in spec) as far as I can tell. It was the first time I’ve ever done it, but unless I’m missing a trick from everything I’ve learned here, I’d really have to suck to get it that wrong. [I’m open minded to my flaws…]

I’ve been to 3 shops with 3 different opinions, nobody doing a teardown b’c they know I want to do my own work and I’m trying to not spend $500 for them to put it back together or to tell me it’s a new engine solution. Opinions:
-Lifter tick
-“Something in the valve train”
-Crank shaft bearing
-Chain whip
-Worn piston
Just to name a few


All of these seem to have something else in the signs/symptoms that don’t add up—no lost performance, not getting worse, rhythmic, no change in temp, etc.

I believe the key is that it does it only in gear…

Have you tried using a mechanic's stethoscope to pinpoint where the clatter is coming from, if not I would suggest getting one, only about $10 or so at your auto parts store.

I used a regular stethoscope with a dowel, been effective for me in the past. If you believe it may make that much of a difference in this case, I can grab one while I'm out today.

What are you driving? V6 V8

In v6 engines the cyl 6 is typically known for head gasket leaks. I wonder if it hydrolocked when you blew out the spark plug. In v8 the exhaust gaskets leak causing a ticking. But you should be able to narrow it down to left or right side.
Also a cracked flywheel would cause a clatter when in gear under torque

No not necessarily, I have used just a dowel, broom handle or a long screwdriver before for a stethoscope and just pressed my ear to the dowel/handle of the screwdriver and it works OK, but the mechanic's is just easier to get into tighter places and does transfers the sound a bit better, either will work if used correctly.

I just find it hard to believe the clatter can't be pinpointed by using such a device.

Could you post a video of the sound? Exhaust leaks can make odd sounds especially under load but you say more of a clank. My truck had a leak between the exhaust manifold and cylinder head. I pressurized the exhaust to find it hissing out.

Happy 2023 gang. Used the auto stethoscope-- you're gonna kill me for this description. In general, it resonates clearly EVERYWHERE. It seems more obvious towards the back of both heads, and down in the valley towards the back. Equal on both sides.

Tried to hit it from everywhere, including find spots like idler bolts, on top and under the heads front and back, as many areas of the block, pump, peripheral areas like alternator, starter, tranny, oil pan, fan, etc.

From underneath it seems to be more obvious towards the back, but nothing dead on. I thought at first maybe it was right at the connection to the tranny (flexplate like suggested), but frankly that sound again seems as audible as it is up top at the back of the heads.

How much is my inability to differentiate tone, how much is resonating from other areas, how much b'c it's seated somewhere indirect I can't hit, who knows. It is different than other ticks and chuffs, much more pronounced.

The clatter is more audible sitting in the cab than standing in front of an open hood. And when underneath. I think that's telling me it's somewhere that's going to require a rebuild or access I don't have the resources for (block, crankshaft, interface etc). Hope I'm wrong... I have no other symptoms of a flex plate issue-- no starting issues, shifting hesitation/jerk, sounds, etc. Overall performance is just fine. (Not saying it can't be)

I start the teardown next week... hope to get further before I do.

@MikeinNH67 , I'll try another video tomorrow with a better source, phone didn't do much of a job.

Wouldn't a manifold leak sound roughly the same regardless of being in gear? Maybe a little diff, but this is significantly different. I do have some chuffing, long while now, and know I need to replace at least one gasket in the pipe after I finish this job if not the entire manifold assembly.

How'd you pressurize that? Just a shop vac up the pipe backwards?

Okay, one from the interior, one from exterior. The video actually picks up exterior better. Interior may need earbuds or really good audio to distinguish, but my explanations are better there.

Interior, most clarity at 1:00.
https://www.youtube.com/watch?v=1HzlfXY1VOo&feature=youtu.be

Exterior
https://www.youtube.com/watch?v=d0t9h_dawv8&feature=youtu.be
(and the hanger whistle made an appearance too )

That doesn't sound good. My guess would be the bottom end but you could pull the valve covers and inspect the valve train. Might be looking at an engine swap as opposed to repairing what you have.

Lol I agree it doesn't sound good. But it's been that way for a year now, no worsening, no poor performance, just annoying as hell.

An engine swap is out of the question for me. It's out of my skillset, resources, and timeframe (this is my daily driver) and wipes out my entire budget for the rest of the work I want to do for the purpose at hand.

You may have to keep driving it as is like you have and hope for the best. Maybe you can get another year out of her. Especially since you brought it to a shop already and they couldn't give you any more specificity without taking it apart. I would say that is a fair assessment.

In my opinion, to get a more definitive answer, it will require further inspection and tear down which will cost more money. Once you find the cause, you will be committed to fixing it or replacing the motor. It wouldn't make sense to me to reassemble it at that point.

Good videos dude, really helped with the clattering sound.

Sounds like it's louder in gear than in neutral. However, like you said, the noise might still be there in neutral but more muted.

Have you thought about investing in chassis ears from amazon? Might help you pinpoint the noise better: Amazon.com: STEELMAN ChassisEAR Electronic Squeak and Rattle Finder Auto Diagnostics Tool, 6 Microphone Clamps with Leads, Over-Ear Headphones : Automotive

This one is a hard one to internet Dx!!!

The second video sounds like what I recall on my exhaust leak. Sometimes a good blip of the throttle could bring on exhaust pops if so. What I did was take a rattle paint can cover, drill a hole in it and attached it to an air blower type thing. I used a hose clamp to secure the inner side of the cover over the exhaust pipe, I think I had to put a slit in the plastic cover. I then turned my air compressor way down to 6 or 8 pounds then released air into system while looking & listening for leaks.

FYI, the timing chains don't need preventative replacement. There is no change interval like a belt has. The painted timing links are the indicator. If, when you have the timing cover off for a re-seal, and you see that the paint is "worn" off the links, that is the indicator for replacement. Overheating is the primary reason the chains could stretch and that heat is what "burns" off the paint on those links. Toyota's timing chains are very beefy and will last the life of the engine.

Of course, there could be other issue that impact the chains, etc., but it's not just a "might as well change them while I'm doing other stuff" thing.