2004 Sequoia ticking noise under load *NOT exhaust

[Colington]

So I bought a new to me 2004 with 155k miles and she’s amazing! Engine sounds healthy, no codes, revs great! However……. Under acceleration it makes a tick tick tick airy sound that increases with throttle. It sounds just like an exhaust leak, but isn’t. I just had the manifolds done, exhaust system redone too. New timing and water pump plus bearings and pulleys. It’s not a lose metal shroud, fan noise, etc. again, it ONLY presents under load accelerating. Not at idle revving. When driving, it sounds like it’s coming from the engine area up front. Here is a video of it in action. Ps, we performed an excessive smoke and pressure test. Nothing!

 

[Colington]

 

[vtl]

Stuck hydraulic lifter?

 

[Colington]

Thanks for the input. I had that thought as well. These dont use hydraulic lifters. Instead it has a bucket and shim style and usually requires some disassembly and cam removal to properly diagnose. That falls outside of my comfort zone to DIY. The whole thing leave me scratching my head. I’ve had 2 master techs drive it and both say it sounds like an exhaust leak. Another guy drove it and said he’s heard a few 4.7’s make this noise and it was never diagnosed. My main concerns at this point our valve lash and had to tackle that or the other possibility is the exhaust shop goofed up not once but twice in which case I would hesitate to bring it back to them for correction.

 

[vtl]

Thanks for the input. I had that thought as well. These dont use hydraulic lifters. Instead it has a bucket and shim style and usually requires some disassembly and cam removal to properly diagnose. That falls outside of my comfort zone to DIY. The whole thing leave me scratching my head. I’ve had 2 master techs drive it and both say it sounds like an exhaust leak. Another guy drove it and said he’s heard a few 4.7’s make this noise and it was never diagnosed. My main concerns at this point our valve lash and had to tackle that or the other possibility is the exhaust shop goofed up not once but twice in which case I would hesitate to bring it back to them for correction.

Oh, you didn't do exhaust yourself. Then yeah, verify if it's exhaust leak.

 

[SoCal818]

Oh, you didn't do exhaust yourself. Then yeah, verify if it's exhaust lea

Thanks for the input. I had that thought as well. These dont use hydraulic lifters. Instead it has a bucket and shim style and usually requires some disassembly and cam removal to properly diagnose. That falls outside of my comfort zone to DIY. The whole thing leave me scratching my head. I’ve had 2 master techs drive it and both say it sounds like an exhaust leak. Another guy drove it and said he’s heard a few 4.7’s make this noise and it was never diagnosed. My main concerns at this point our valve lash and had to tackle that or the other possibility is the exhaust shop goofed up not once but twice in which case I would hesitate to bring it back to them for correction.

Were you able to determine the cause of the ticking? I’ve got a similar noise with my 05. Doesn’t change after the engine warms up (usually a sign it’s an exhaust leak). A buddy of mine has a GX470 with the same motor and says he was told by a Lexus tech the noise is just part of normal engine operation. I question that claim but I’m not a mechanic.

 

[Colington]

Were you able to determine the cause of the ticking? I’ve got a similar noise with my 05. Doesn’t change after the engine warms up (usually a sign it’s an exhaust leak). A buddy of mine has a GX470 with the same motor and says he was told by a Lexus tech the noise is just part of normal engine operation. I question that claim but I’m not a mechanic.

Sorry you’re having the same issues. I brought it to the Toyota dealership on Saturday to be looked at by a master tech today. Hopefully, I’ll have some answers by the end of the day and perhaps I can even point you in a good direction. A lot of forums and conversations I’ve had do indicate that “this is just how they sound”, but I’ve owned nearly a dozen vehicles with this engine, and I’ve never experienced this noise. Stay tuned.

 

[Colington]

Were you able to determine the cause of the ticking? I’ve got a similar noise with my 05. Doesn’t change after the engine warms up (usually a sign it’s an exhaust leak). A buddy of mine has a GX470 with the same motor and says he was told by a Lexus tech the noise is just part of normal engine operation. I question that claim but I’m not a mechanic.

Toyota dealership finally diagnosed as faulty Cats. Sadly both of them. Air was escaping at the O2 sensor and rattling the honeycomb inside the cats. Looks like a $$ fix. Yay

 

[SoCal818]

Toyota dealership finally diagnosed as faulty Cats. Sadly both of them. Air was escaping at the O2 sensor and rattling the honeycomb inside the cats. Looks like a $$ fix. Yay

Oh, that’s not good. Did it throw codes or any other signs? Now I’ve got to crawl under my rig this weekend to check whether that’s the source of the noise. Thanks for sharing the diagnosis.

 

[Colington]

Oh, that’s not good. Did it throw codes or any other signs? Now I’ve got to crawl under my rig this weekend to check whether that’s the source of the noise. Thanks for sharing the diagnosis.

No codes or symptoms at all outside of the airy ticking noise. The driver side bank ran hotter according to my IR thermometer, but that’s it. 22 years and 155k is a decent run for Cats I suppose. OEM parts aren’t available anymore so I’ll be looking for “quality” aftermarket options. My exhaust shop offers magnaflow $500 or there is EBay cross your fingers sets for 100-250 for the pair… what could possibly go wrong

PSA. Typical smoke test do not find the issue. They had to drive cycle it several times with a microphone on a magnet under the car to identify the area where the noise was coming from. Pretty high tech for a dealership. Kudos to them.

 

[vtl]

Absolutely don't thrown away your OE cats. Take downpipes out and inspect with camera. Unless combs are melted, they can be reused. You just need to weld a new downpipe or parts of it. I regret so much I disposed my fully metallic platinum cats on one of my vehicles. Magnaflow is plated ceramic, it's not nearly as good as durable as fully metallic cat. It does not throw codes only because the car has an aftermarket stage 1 ECU tune, which ignores readings from rear oxygen sensor, which perhaps screams already that the cat is dead.

Maybe your OE downpipes have enough meat for repair. Weld holes, change flex section, add insulation around cats.

 

[Colington]

Back to square one. Replaced the entire exhaust, cats, muffler, manifolds etc. The noise remains totally unchanged. This is a big head scratcher for sure. It leaves valve seats, buckets, pre detonation issues possibly…. Toyota master tech and foreman said exhaust, exhaust shop did everything they can do and no result (except for my bank account while everyone practices diagnostic tech)

 

[SoCal818]

Back to square one. Replaced the entire exhaust, cats, muffler, manifolds etc. The noise remains totally unchanged. This is a big head scratcher for sure. It leaves valve seats, buckets, pre detonation issues possibly…. Toyota master tech and foreman said exhaust, exhaust shop did everything they can do and no result (except for my bank account while everyone practices diagnostic tech)

Ouch!

 

[Colington]

Whelp…. Here we are, a month in and no resolution. I’ve replaced both CATS, manifolds AGAIN just in case… basically the entire exhaust system for the second time. The shop wasn’t supposed to toss my OE cats, but they did! Arghhhhhhh! It was pretty hot yesterday when I picked it up and had the AC on max. That seemed to “cover up the noise” but nothing has actually changed. A friend in San Diego recommended I inspect for vacuum leaks at the intake manifold and check the grommet at the steering rack to see if perhaps normal noise is just leaking into the cabin from a failed barrier. I’m really scraping the bottom here. Any input is welcomed.

Side note, I installed diode dynamics SS3 fogs and they can’t hold a candle to Baja design units.

 

[vtl]

Whelp…. Here we are, a month in and no resolution. I’ve replaced both CATS, manifolds AGAIN just in case… basically the entire exhaust system for the second time. The shop wasn’t supposed to toss my OE cats, but they did! Arghhhhhhh! It was pretty hot yesterday when I picked it up and had the AC on max. That seemed to “cover up the noise” but nothing has actually changed. A friend in San Diego recommended I inspect for vacuum leaks at the intake manifold and check the grommet at the steering rack to see if perhaps normal noise is just leaking into the cabin from a failed barrier. I’m really scraping the bottom here. Any input is welcomed.

You friend actually said a thing. When this grommet/boot failed on one of my cars, I was hearing everything happening under the hood so much louder. Even heard the hissing and staccato of turbo (WOOOSHHH-T-T-T-T-T-T)... Sort of liked the turbo sounds, but not the rest.