orozco543

iTrader: (1)

Since mid-May, my GS400 has made a soft ticking sound (sort of like shuffling a deck of playing cards, but a little more metallic-sounding) when I accelerate briskly. At a steady speed, the engine runs smoothly, and the idle sound and RPM are perfect. It's not a loud ticking sound--it's so high-pitched that my dad could not hear it when he drove the car to the airport last week. .

It only happens when the car is in gear, though: revving the engine in Park doesn't seem to cause the sound. I put the transmission in Normal, ECT Power, and Manual modes, and the sound still occurs.

I did a transmission drain and fill and changed my oil. I don't have a CEL and fuel economy is normal at 18 MPG.

I searched for this issue, and came up with a couple responses/explanations that are possible.

(1. My car needs a valve adjustment. After 124k miles, this seems possible.

(2. It's the valves, but this noise is normal for a Lexus V8. (But why did my car accelerate without making this noise when I bought it in 2010??)

I don't relish the thought of having the valves adjusted ($$$) if that isn't even the main issue. I'm kind of hoping that it's an exhaust problem instead, but I doubt it.

I'd really appreciate any thoughts you might have before I bring this to an independent Lex mechanic.

Enigmatic

I have a GS300 and this happens to me only when I first turn the car on in the morning and get going. For the rest of the day it is fine. I don't know if that helps you or not but I just figured I would give my input. I do not think it is very detrimental or anything. It almost sounds like the exhaust vibrating ever so slightly or something along those lines.

DosyBoy

iTrader: (1)

Oil level is low or if not, its without a doubt a valve adjustment needed, its about $600-$800, if thats all thats wrong.

orozco543

iTrader: (1)

The oil level is still halfway between full and low, so that can't be the issue.

I read your thread about your valve adjustment, and I know it worked for you. I guess I will live with the noise for now & drown it out with music; once my passengers start complaining, then I know it's gotten bad enough to fix. I can afford to adjust the valves now, but I'd feel like a real chump to pay $700 only for my mechanic to tell me that the valves were only the slightest bit out of spec.

Or I can drive my car like a grandma and avoid the sound that way. 9 seconds to sixty FTW.

Arcadian

Or, just bite the bullet, get the valves adjusted, then get back on the throttle.

DosyBoy

iTrader: (1)

Yea if u want the engine to perform to the best of its abilities i would def bite the bullet if u plan on keeping the car for a few more years..

GS4_Fiend

iTrader: (22)

Post a video. I'm assuming exhaust leak.

mtparker18

Could it be injector pulses?

Enigmatic

I got a valve adjustment about 5000 miles ago, so this cannot be the issue. I am pretty sure it is something with the exhaust.

GS714

Enigmatic, Did you tried to turn the climate control, i.e turn on the A/C, or/and change fan speed. My just started making rattle sound from the center of dash for two or three second and went away a few second later.

billzblaze

my gs400 also makes a similar noise kinda sounds like an old truck when i press the gas i am missing a bolt in the exhaust manifold so its either that or a leak..

Busha

It can also be poor gas and your hearing the engine pinging

GS714

I thought that only take place during high RPM. I use 91 Octane only.