Fizzboy7

I have a 2008 IS250 with 14k miles. I don't even know if engines still use lifters, but I recall several Acura's that made this sound as they aged. Upon start-up, for a few seconds, my enging makes a faint clattering sound, then dies off within a few seconds. This noise is NOT the same as the widely noted metal/starter sound with it's own TSB. It is also NOT the same diesel engine sound and direct injection ticking we've all talked about before. I know what all those sound like and it is none of those. It's more of the lifters clicking or clattering up and down for two to three seconds, then it goes away. I did several searches here and I'll I come up with is the metal starter TSB and the normal DI sound. Again, it is neither of those. Any help would be appreciated.

(It is NOT this sound.... https://www.clublexus.com/forums/is-...erships-3.html)

SC3coupe

iTrader: (4)

So what do you want to do about lifter sound, unless they were revised and you want them?

I believe it's no harm to the engine.

Fizzboy7

Perhaps, but the car has never made the noise until this week and that raises some questions and curiousities. With a scheduled service coming up, I would like to arm myself with as much info as possible for the dealer. Sometimes they need all the help they can get, especially when it comes to possible TSB issues.

axis77

just a fyi, i turned in my 2007 is250 last Thursday for maint.for these 3 things, tpms sensors keep coming on/off , car stalls/sputters slightly when i come to stops, and i hear this chatter when i start my vehicle - they say they need to adjust or replace my valve springs....so ive had a lexus loaner for 5 days now!!

Fizzboy7

Thank you for this info! I will use it when I head in for service next week. If you can report back later on whether it fixed it or not, that would rock!

hanzie411

i took mine in for a grinding/rubbing sound at startup (not all the time), and the dealer sounded like they knew this was a problem, and they replaced my cam gears.

RA030724

iTrader: (1)

I've had the same thing happen about 3 times in the 2 years I've had my car. It almost sounds like "engine knock" and since the weather has been hot and humid each time, I assumed the computer mis-adjusted the fuel mixture at start-up. Goes away immediately. And, yes, like Fizzboy7 I have heard similar noises at startup in other fuel-injected vehicles I've had over the years. I'd be interested in what your dealer finds/says.

Fizzboy7

Now it's interesting you mentioned the humidity thing. Mine has only done it when it was humid out. I'm not hearing it now that it's dry. Hmmmm...

RA030724

iTrader: (1)

Like I said, I really haven't worried about it because due to weather conditions, I could understand how the computer might mis-read the sensors at start-up and advance/retard the spark incorrectly or fuel mixture. I know with my 2004 RX it would always go two full cranks before firing on the third. The dealer said that the engine read the sensors on first two revolutions, then fired on third. That seem to be plausible as two other RX's did the same. My 2008 IS doesn't and fires immediately on first crank, so it I'm guessing it assumes mixture conditions from shutdown. To me it just sounds like a bad case of detonation (engine knock) for the first couple of seconds until the computer recalculates the mixture/spark. If you don't have a problem on a regular basis, I wouldn't worry.

dojoman

iTrader: (5)

Interesting this issue is popping up just about now. I just noticed mine, started yesterday morning. Cold start and rattle noise comes from mid dash area. the noise comes at the end of startup, very short...probably 1 sec, not loud but noticeable in cabin. I cannot duplicate it right after but 8 hrs later the same noise at startup. I will try to record it from outside. I thought Cam shaft knocking noise only affects 06-07 but seems like 08 is happening too.

RA030724

iTrader: (1)

yeah, but you are an IS350. We are both IS 250's. Can't believe it is a mechanical issue like cams or lifters with two separate engine designs. Still think it is a software issue with the fuel management if even a "problem" at all.

dojoman

iTrader: (5)

I just recorded the sound. It's very clear at the end. Are you guys talking about the same sound?

Mv350

iTrader: (23)

i have had that same noise a couple times but then it stopped completely.

dojoman

iTrader: (5)

Did it happen close to oil change interval? Mine oil is due soon and some people were saying if the oil level is low you might hear this noise?

Fizzboy7

I can't get my computer's volume high enough up to hear. I'll check on my mom's computer tomorrow and report back.
Are you giving the car gas when starting it? Mine was doing it with just a regular start.