Chris98vob

I hope someone has heard this sound before and can tell me what it is and if it is an issue. I have an 07 GX with 45K miles on it. I've noticed when I start it in the morning or when it has been sitting for a bit I hear a thumping sound when I put it into gear. This happens only when it is cold and seems to go completely away when it is warmed up.

The sound can be heard when it is in Drive or Reverse with the foot on the brake. It is a fast thump at maybe 3 or 4 per second that seems to come from the lower part of the engine. It sounds like it may be coming from the front transaxle. It doesn't sound like a rod bearing.

Has anyone ever heard this? Any thoughts about what it is?

I am about out of warranty so will take it in if it is a problem, but given it can only be heard when it is cold I know this will mean them keeping it overnight so I don't want to waste my time if it is normal.

Chris98vob

I should add that while it can be heard if you listen carefully from the outside, it is quite noticeable on the inside.

cssnms

Take it in no matter what someone on here thinks while you still have warranty coverage. I would hate to see an owner rely on someone's cyber diagnosis only to find out after the fact that it was wrong!

That said, if it's what I think it is it's normal, but let Lexus figure it out. Good luck.

Arroz

I have it too, but only notice it in reverse.

dbacf

no brainer, under warranty take it to the dealer.

Lexus 4 ME

I have 2004 with 40k miles and I never noticed. Take it to the dealer make sure they do the test when its cold.

Chris98vob

I'll follow your advice and am bringing it in Monday. The guy in service says in 4 years he has never heard that sound so it seems likely an issue. Maybe I am catching it early before it does much damage. The tough part is not only does it only happen at startup when the engine hasn't run for many hours, but it stops pretty quickly. I heard it a little bit ago and then drove one block and it had stopped.

stiles_s

FWIW, my 2007 does it as well -- has done it since new as far as i can remember. Goes away when the tranny warms up a bit.

Not saying it's "good", just that someone else is experiencing the same thing.

mann777

I will agree with CS .....go to the dealer....
this sounds like a Engine Baffle to me...there is a TSB issued, to this effect, anyways goto the dealer and let us know what it is.

stiles_s

What's an engine baffle?

Chris98vob

I took it in yesterday afternoon and they kept it overnight. The dealer just called me and heard the sound and said it was "perfectly normal" until it warms up. I live in Austin, TX so it is rarely cold here so I guess I never noticed it before.

I am also curious about what an engine baffle is. If it is the problem, though insignificant, I'd like it fixed.

The only Baffle I am aware of is the one in the oil pan. Is that the "engine baffle" you are talking about?

Chris

cssnms

Good move taking it in, better safe than sorry.

It's not a "baffle" it's what I thought it was, the common cold clearance noises from the valve train typical of Toyota V-8 engines - we all have it.

Chris98vob

Good to know. They checked the car completely out. Found that the battery was on its last legs (I hadn't noticed a slow start at all) and put in a new battery under warranty. I can't complain about that.

Only bad thing is the free car wash won't be any good because it is raining here.