Our GX just hit 1,000 miles not too long ago, so I've fianlly had a chance to take it up to 75 mph on the highway a few times. During the break in, we never really went over 55. The GX is totally quiet up to 55. From 55 to 65, there is a slight moaning/growning noise (maybe more like an exhaust resonating sound) that I hear when you're steady on the throttle or accelerating. The minute you let up off the pedal, you don't hear it anymore. Above 65 mph, it becomes totally quiet again.

Has anyone else ever experienced this? This isn't the vibration problem I've heard about that happens at 1,800 rpms, is it? There's no vibrating whatsoever. It truly sounds more engine/exhaust related. I haven't gotten a chance to drive my in-law's GX at that speed to see if it's the same.

 

It's funny that you mention that. I just noticed last night that there was a low, barely audible noise coming from the rear of the truck at highway speeds. When you took your foot of the gas, it would disappear. it was kind of like a fluctuating, or undulating noise. No clue!!

 

Yeah, its there but that's what a V8 is supposed to sound like. The GX would sound awesome with exhaust headers on it. Not like those 4 and 6 cylinder engines people put headers on, the GX has a great low sound to it.

Too bad no headers exist.

 

having 22k on mine, i haven't noticed or felt this before! (good thing though, lol)

 

While I don't yet own a Lexus, I find it hard to believe that it needs to be babied for the first however many miles. No car today should need to be babied. In fact, thee's a school of thought that engines should be opened up to seat them properly in the beginning.

 

Could be but at these prices, we tend to go along with Lexus' recommendations on the break in period.

A while back, I remember a thread talking about a "drone". There may be an associated TSB covering that and possibly steering wheel vibration. I have heard a drone in my truck but it only happens on a stretch of freeway that has grooves gouged into the concrete for rain runoff.

 

You may not own a Lexus but The manual states "you need not follow a break-in schedule with your new Lexus." So it's just opional. My friend just bought a brand new 2005 Honda Civic Sedan last week and it states that it does require a break-in schedule.

 

You dont need to follow anny specific break in with a lexus.

The vibration you are feeling is more then likely the one reported here many times before. Most all GX's have it.

Some GX's also have a rear axle whine. Its reported mostly at higher speeds (75-85mph) and comes and goes with the amount of throttle that's being fed in.

 

While it's true you don't NEED to and in fact the manual is somewhat confusing on the matter (first sentence in the paragraph says you do not need to..). But it does say a couple of things like : "...avoid hard braking for the first 200 miles...", "... avoid towing for the first 500 miles...", and for the first 1000 miles "...you will experience better mileage..." and something about longer trouble free life (or something I don't have the manual), if you "... avoid full throttle accelerations...".

As an update (instead of depending on my memory) here is the exact text from the owner's manual:

BREAK–IN PERIOD

Drive gently and avoid high speeds.

You need not follow a break–in schedule with your new Lexus.
But following a few simple tips for the first 1600 km (1000 miles)
can add to the future economy and long life of your vehicle:
- Avoid full throttle acceleration when starting and driving.
- Avoid racing the engine.
- Try to avoid hard stops during the first 300 km (200 miles).
- Do not drive for a long time at any single speed, either fast
or slow.
- Do not tow a trailer during the first 800 km (500 miles)

 

I read this from a posting from Edmunds forums:
http://www.lcool.org/technical/120_s...tion/90hz.html

This is the same car as the GX470. Looks like this is the fix to your problem.

 

During the test drive, I took it up to 80 mph and heard the exhaust . I asked my sales guy and he says to punch it again . The tone growled again......Yep, It's the power of the V8 and I like it. YOu mentioned that there weren't any vibration, so you're totally safe.
Not sure if it could be louder with the chrome tip?
Actually on some tundras, yukons,...with just chrome tip and when one passes by, I noticed that they are pretty noticeable, not annoying but loud.

 

I doubt it, unless you cut off a piece of the tail pipe and weld the tip on. Even then, it may not make any difference. As it is now, the exhaust pipe comes out almost to the end of the tip.

~ Cap

 

The exhaust tip on my truck was put on after about six months of ownership. There are no differences between "before and after", other than looking a lot better.

 

I said this to myself too, but I've seen yukons... with chrome tips are alot louder than the one without??? I really don't care about this, but just a wee bit curious.

 

Might be because someone who has switched to a glass pack muffler or even a dual exhaust system with glass packs would more than likely have chrome exhaust tips too.