Strange Noise When Ice Shuts Down On Cold Start.

[aus_rx400h]

Hi Guys,

Just wondering if anyone has experienced a strange sound on the rx400h. When I start the car up in the morning, ICE generally runs for 1.5 mins and then automatically shuts down. This is quite normal but on a few occasions when ICE is shutting down, I hear what sounds like a chain on a pully sound 'click click click' as the engine is turning off. I stress this sound is only happening on cold start but it doesn't happen every time. Just the odd occasions.

[RX400h]

How cold is it when this happens?

[aus_rx400h]

How cold is it when this happens?

It's summer here so morning temperature is on average 20 degree or 68 degree Fahrenheit. Actually, now that I'm keeping an ear out, I notice that I'm only getting it on the odd occasion and the only time I hear it is when i start up the car, ICE runs for a minute and then switch off. Doesn't do it every time though. I've mentioned this to my Lexus dealer so was told to drop her in for one the engineer to check it out.

[FrenchSpy]

I hear lots of strange noises when I turn it off my RX440H. Not only in cold weather, but it depends on engine temperature.

These noises appear a few seconds later. Pump noise and "clik-clik".

My car is a 2005 model (yes, that's true in Europe, the first delivery in December)

Never fear, it seems normal....

PS: Sorry for my poor english

[aus_rx400h]

As I've tried to explain, I hear this sound when ICE is SWITCHING OFF so it is only for a second, not after, and it sounds like a chain pulley.

[lemon]

Look at the TSB in point #8 in this post

http://us.lexusownersclub.com/forums/index.php?showtopic=58929

Specifically,

It is important to perform the ISC Learning procedure anytime the 12–volt battery is

disconnected or the voltage falls below 7 volts. This procedure allows the I.C. (internal

combustion) Engine to re–learn its optimal idle speed during the initial engine warm–up

cycle or charging the HV battery. If this procedure is NOT performed, the following

customer complaints may occur:

Engine runs too long or more frequently than normal

Reduced fuel economy

Transmission gear “clatter” noise at idle is more pronounced

Maybe this clatter noise is what you're hearing? I've heard this noise before on my own vehicle prior to doing the ISC reset, but it definitely sounds like it's coming from down low in the vehicle (like down where the transaxle is).

Now, this TSB is for the 2006, but it came out in 2006. Whether it applies to later years I don't know. Still, it wouldn't hurt to print it out and ask the dealer to check that the ISC procedure is complete (they can use the Lexus computer that hooks up to the ODBII port). Alternatively, you could do the ISC reset yourself (look up the procedure in this forum). It's easy enough, and owner's that have other years than 2006 have done it and reported increased gas mileage.