clubsport

ah very nice trick, i thought i knew a lot about exhaust but i guess you either forget or somethin... thanx ancient
i will do a 5/30 synthetic oil change today then and then we'll see... mine is only 51k miles so hopefully it's not the rust or the valve (hard to get to given this a truck) or is it radiator? i see some pink so will do some pluggin i guess...

i plan to fix every issues with this truck cuz im keepin it forever and ever... seriously i will... lol

clubsport

i finally figured out where my wind noise is coming from - it's the main muffler (resonator) rattling against heatshiled i think but i can replicate the noise now with pushing on the muffler... gonna get that fixed with next oil change

even in park i hear the wind noise so i knew must be engine or exhaust - turns out exhaust... lucky me cuz could've been much worse...

Muti007

Ahhh, now that makes sense I didnt understand the same response in a 3 year old thread about sunroof news, lol.

SCuster

I've done a lot of research here and this cost some dollars on misdiagnosis. The Manifold gaskets cause a ticking sound due to leaks until the steel heats expanding the steel and shutting down the leak. This flow problem also can trip the o2 sensors throwing the christmas tree of lights, check engine, TRAC OFF, and SKID off. Odd thing Lexus decided to trip all the lights but I guess they want to scare you to the dealership when and EPA problem arises.
The proper fix can include replacing both right and left banks with gaskets. This includes the 1st stage CAT converters which are part of the same section of pipe. There are "shortcut" fix's for do it yourselfers like pulling the pipes and replacing the gaskets only but if your 100K or more might as well replace the CATs as well just to avoid the same lights for a different issue when the CATS are not getting proper flow.


Good luck, and thank Lexus for some very sub par manifolds for their V8 package and a seriously over done emissions control system.

RCsGX

It's not just Lexus that has the leaking manifolds. 1st gen Tundra's and Sequoia's have the same problem too.

Crispy3M

Take a look at this thread. I've thrown in some pictures. As you can see, the Lexus manifold is extremely thin and the flanges tend to crack, which may be causing the ticking sound you are hearing.

Hope this helps!

Cheers,

Chris

https://www.clublexus.com/forums/gx-...ing-sound.html

ROSCOGX470

How hard is it to just replace the manifold gasket? Can the gasket slip in after the bolts come out or does the cat end have to be unbolted too? The pics of the pacesetter replacement looks like the old manifold itself was ok.

Crispy3M

It's very hard to tell, even when you have it in your hand, but because the flange that mates to the head is so thin, it cracks all around the "lip" and leaks.

You can try welding it... I welded both. The right side took and the left side didn't. After that, I just ordered the Pacesetter set and replaced both.