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Occasionally when I first start the engine of my 2006 IS350 after it has been sitting overnight, just as the engine is settling down to normal idle speed there is a loud, rapid ratcheting or rattling sound from the engine compartment for a couple of seconds. It is a real pride-killer, since the car for that moment sounds like a piece of junk. This noise is distinct from the well-documented clicking sound attributed to direct injection. So far I have received no satisfaction from either lexus.com or my local dealer. I don't know if this noise, too, could be somehow related to direct injection or if on occasion the anti-drainback valve in the oil filter does not seat properrly and the valve train is momentarily starved for oil pressure. Has anyone else had this problem and does anyone have an explanation?

There is the sound of a servo motor that comes from under the dash, which I believe, is unlocking the steering wheel, etc when the ignition is turned on.

You have described my exact problem and it just started recently (within the past week). It happens after the car has been sitting overnight and it was the loudest today when the temperature got a little cooler. I will be visiting the dealer tommorrow and will keep you posted. This is pretty disappointing as the car barely has 8k on it.

I have the same exact problem, just as I start the car and the engine crancks, I hear a brief metallic rattling noise, it actually sounds almost like the noise you hear when you stick a paper in a fan for like a second (except more metallic). It is really frustrating because it doesn't happen every time so it's hard to detect the cause/source. I have my IS350 for about six months and it started a couple of weeks ago just when I crossed the 4000 miles. When I took my car in for the 5000 miles service a few days ago, I reported the problem to the Lexus service dept. When I got my car back I was told they checked all possible reasons, but since they were unable to duplicate the noise they couldn't make a detrmination of what's wrong with it and as far as they are concerned the car is OK. Will keep trying to figure it out and inform you. If anyone manages to solve this mystery please let me know. Thanks.

** UPDATE **

I realized that there is a link between the gas I put, (not the octane, which is always 91 or higher, but rather the gas station and the quality of gas you get there) and the noise at start-up. In retrospect, I noticed that the noise made an appearance when I filled gas a couple of times at gas stations other than the one I usually go to. I am very particular about putting at least 91 octane, but it is more than likely that the gas was not up to standards at those gas stations. Maybe your neighborhood/usual gas station is not consistent with the quality of gas they sell you. The noise may well be a side effect of impurities in the gas. My usual gas station is Chevron which is near my house and I've never had a noise problem when I filled gas there (I always put 93 octane). Since I filled about two tanks of clean gas there, the noise completely disappeared, and for the last few weeks NO NOISE! From now on, I'll make it a point to fill gas at my usual gas station and keep close attention if the noise makes another appearance. Good Luck!

Update

I hope mike1 is correct, but I am somewhat skeptical. I, too, have noticed a possible connection between the fuel system and the engine noise at ignition. More often than not, these noises occur the morning after I have recently topped off the gas tank. I always fill up at the same station with Amoco filtered premium. These noises did not occur when the car was brand new (same gas, same station) and now occur occasionally, mostly after a fill-up. This leads me to believe that the connection, if there is one and it is not a coincidence, has to do with the direct injection pressurization pump and a full tank rather than what gas was purchased. In reality, I am still groping in the dark here. More replies welcome. Thanks.

Mystery Solved?

I ran across a much more detailed discussion of this apparently widespread problem at clublexus.com. The consensus there seems to be that the problem is due to hydraulic lash control in the valvetrain. If oil drains from the tensioning mechanism there is clatter until the sytem "pumps up." The same discussion mentions a service bulletin recommending 5W-20 oil rather than the 5W-30 listed in the owner's manual. This is news to me, and I am trying to confirm this with Lexus. Also, a few respondents say that the onerous noise tends to go away by 12-14,000 miles. Don't know if I can stand it that long. This explanation is the most logical one I have yet heard. A pity that there is nothing so far from Lexus. Could it be that they simply don't want to acknowledge a design flaw?

There is a bulletin for 2006 gs300 to replace valve liftere due to misfire codes. It also applies to is350's, same engine. Just because the bulletin says to replace lifters for a misfire isn't the only time it applies. Sounds like your lifters are dragging enough to not cause a misfire, just create noise.

You can check out the TSB's at:

http://techinfo.lexus.com/

Last Word

I finally got an official verdict from my Lexus dealer after a Lexus technical representative made his regularly scheduled visit and listened to a recording I had made of the noise in question. This representative, I am told, is in touch with Lexus engineers and is both qualified and authorized to respond. He says that this noise is NORMAL for the IS350 engine because the engine is technologically advanced and has "racing pistons" that are machined to very close tolerances and can be momentarily starved for oil during certain start-up situations. Supposedly this has been taken into account in the design of the powerplant and does not represent something that will cause premature wear or failure. I asked the service manager why Lexus would choose to go this route given the fact that its customer base has been carefully conditioned to expect quiet operation from Lexus vehicles. He replied that there is an industry-wide customer demand for more performance from luxury cars and that engineers are pressed to squeeze every drop of horsepower and torque from a given displacement. I understand that the IS350 is Lexus' performance entry, and I find that performance quite satisfying, but I wish I had been privy to the price exacted for that performance--namely the diesel-like clicking and the occasional raucous rattle on ignition. My buying decision might or might not have been the same. To translate: It's not fair, but it's there; get used to it. So, the next time a friend or acquaintance hears this noise and asks, "What was that?" just reply, "My very expensive racing pistons, and your crinkled up nose is merely a sign of piston envy."

I've had my IS 350 for a little over a year and I've never heard any unusual sounds on starting the engine.

You have described this problem very well. My 350 developed this at around 5000 miles also. It now has 12,000. Dealer has been unable to diagnose due to being very intermittent. Recently took car in for annual safety and emmission inspection and told them to keep it until they diagnosed noise. To my surprise (one day later), dealer called and said they found the cause and it is described in a Technical Service Bulletin (don't know which yet) and that parts were ordered and will be repaired under warranty. I was told it was something to do with one of the overhead cams (chain tensioner possibly??). Any ways, for those that experience this annoying noise, sounds like there is a solution. When I find the TSB number, I will pass along.

Thank you.
I appreciate any update on the TSB. I now have 13000 miles and the noise never stopped. In fact I think it got worse in the sense that it makes an appearance every time I start the car, and not just every once in a while like before. My 15000 mile service is comming up soon and I'd love to get rid of this noise once and for all.

OK. Here is the scoop on this grinding noise at start-up. As I reported previously, my dealer finally diagnosed the noise in my IS350 and noted that a TSIB was issued to remedy the problem. Thanks to Member 'mehullica', I can report that the TSIB number is EG019-07, titled "Brief Enginer Knock/Noise at Cold Start". It is designated for IS350 '06 - '07's. It covers these model years for VIN #'s before JTHBE262#72009954 (TMK Producing Plant) and JTHBE262#75015099 (Tahara Producing Plant). The required repair is covered under the Lexus Powertrain Warranty (72 months or 70,000 miles).

As I read through the TSIB, I was astonished at how invasive the repair proceedure is. Virtually the entire top end of the engine must be dismantled including the intake cams (left an right). The repair involves replacing the intake Camshaft Gear Assembly and is estimated to take 6 hours. I certainly hope that the dealer service techs are well trained for this major repair.

Not exactly what I bargained for when deciding to purchase my first Lexus. I went the Lexus route versus BMW to avoid this type of major headache. Will be my last Lexus if my dealer can't make it right.

Anyways, hope this is helpful for those who have experienced this issue. I will report back with the results of my repair experience.

Hopefully the attachment of the TSIB comes through with this reply.

So this problem shouldn't affect 2008 models then???

The VIN's affected should be listed on the TSB.

This is only anectdotal but some of us have noticed that those who are changing oil more often haven't had this noise. This is like 3000 mile changes = no noise. 5000 mile changes = noise, especially 3500 - 4000 miles into an oil change. Just a thought.

Quick update. Parts are finally in at dealer and have scheduled repair on 9/24. Will provide report on outcome of service when complete.

Wow - I am having the same problem. Will be waiting anxiously to hear the results of the repair...

Update: My dealer completed the TSIB repair last week and so far all is well. Theypicked up my car on a Monday morning and returned it Thursday at noon. They actually had it completed Wednesday afternoon but wanted to keep overnight to make several cold starts to see if noise issue was resolved. So far, I have heard no noise. For those that have experienced this problem, this is the proper remedy. Forget all the non-sense about oil viscosity and frequent changes. I will report back to this chain of messages if the noise returns. Good luck to all.

This sounds like the exact problem I have

on my IS250.

I got back from a one week trip, and when starting it up the next morning, it rattled worse than I have ever heard. It only does it on "cooler" mornings after it has been sitting for a while, and then it only lasts a second.

I am going to try 5w20 oil before I bring it in though.

This is David B in S.C. My local Lexus dealer tells me that the service bulletin mentioned here has been discontinued, that it was an attempt to "quieten things down in the engine" but was apparently unsuccessful. The service personnel there insist that the occasional cold start knock is due to a "short-collar" performance piston and is to be considered normal and harmless. I don't know what to believe.

[/quote]
This is David B in S.C. My local Lexus dealer tells me that the service bulletin mentioned here has been discontinued, that it was an attempt to "quieten things down in the engine" but was apparently unsuccessful. The service personnel there insist that the occasional cold start knock is due to a "short-collar" performance piston and is to be considered normal and harmless. I don't know what to believe.
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They fixed mine like 2 weeks ago. I have been having the issue since I had 8k miles on my car. I now have 18k, so probably about 8-9 months I've been having the issue. What I had to do to get them to repair it was record it happening on audio tape and take it in. They tried to tell me it was normal. So I simply said I want to see every single is350 on the lot do it then. And that if the noise is normal I no longer want this car as I feel I will have to rebuild my engine after 50k miles or so. The tech was like "lexus makes quality engines, you won't have to rebuild it. blah blah blah". I left the car with them, they told me they couldn't reproduce the noise. Then the next day they called me back and were like " Oh there is a service bulletin on your car". Then they listed all the parts that had to be replaced, which pretty much equated to $5000 worth of repair I would say and a rebuild of the top of the motor. Lets just say I was very amused since I have been complaining about this issue forever and they haven't listened. They had my car for 2 days and it runs as if it was new again. The initial plan was to keep this car long term (10 or so years) but now I'm thinking I want to dump it for something more reliable. I have serious doubts in the workmanship inside the IS line. It is definately the last first gen car I ever buy.

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It is definately the last first gen car I ever buy.
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Man, this is not a first gen IS.

I heard a lot of stories like this about my IS from Sterling McCall Lexus in Houston before I moved to Miami. I agree with your comment that service techs don't know much about the IS. BUT this Lexus problem, I mean how could they compete with other makers and don't have competent techs?

11 October 2008,
My local Lexus dealer just performed this repair on my IS 350 regarding the startup noise and it wasn't even making any noise, they're looking for work and Lexus is paying!!

...

I have a 08 and report that I get it. Only happened recently for me too, within the last month or so.

I've had my 2006 IS350 for 2 months now and i just noticed this sound. It does it like every 10 or so startup's, it's very weird. It also make it nearly impossible to show the dealer as you never know when it's going to happen. My car just his 40k too. At first I also thought something was caught in the radiator fan.

It's the Vvti. There's a position that they can come to rest in when you turn the car off and it gets cold, then restart it and it causes them to rattle. There's a TSB out on it. Tell your tech and they will keep the car for a few days and try to get it ot do it for them. Once they determine it is doing it, they have a kit put together, but it does take a couple days to get done, so you'll be without your ride for awhile. But I would only have them replace the Vvti system if you really have to. They literally have to take your entire engine's top end out to get it done. That isn't something you want them to do so you can have a new part on your motor. There's nothing like a factory sealed motor. Once you open it, "things" just don't fit back together right, or the same. And later "other" things start happening.

^^^I agree with you on that one. It the noise bad for the motor, will it shorten it's life. If not then I have not problem in leaving it alone. I'm running 5w30 mobil one sythetic in it so i'm hoping to get much life out of it. I just hope my tranny lasts as long as the motor!

Well it's starting to do it more now during startup. I hear everyone saying it does it when it's cold. It's been nothing but 80+ degree for the past couple months. Yesterday it made the noise twice and it made tyhe noise once the day before. When I got out of work after an 8 hour day it did it during start up it also did it after I left the gym and the car was only turned off for an hour. It's weird because some morningswhen i wake up and start it up the sound does not happen, it's 100% random but it's starting to become more common, I would not say it happens one of of every 5 times. I'm beginning to think it may be something else but the ratcheting sound fits the decription so well. Once it's started it purrs like a kitten.

I had the same problem, took it in and the dealer told me it was a problem with the cam gears, of course its under warranty and they replaced wutever they needed to replace and the noise is gone.......hope this helps.

Does anyone have the TSB on this? I've been looking and can't find it. I have done alot of research on it and I now know exactly what it is. It appears that the majority for is350 owners have this problem. Someone on another IS forum recorded the sound and it sounded just like mine. According to lexus it is a VVTI actuator or something like that. There are two of them but some dealers only replace one. It also does not require a removal of the head as some may think.

http://www.lexustsb.com/questions/201/TSIB...At+Cold+Startup

Great thanks! I'm going to need to bring this to my dealer so I don't get the run around.

I have a 2007 is 350 , if I dont get the rattling fixed do you know if it will shorten the life of the engine or will cause something else to go wrong or loose power ? thanks

I did some digging and could not find a definitive answer so I’ll ask here.

Is the power train warranty transferable?

If so, does it still cover this TSIB repair?

I have an ’06 IS 350 with about 56,000 miles on the clock that has this issue about 10% of the time on cold startup.

Yes the lexus warranty is transferable. If you have less than 70,000 miles get it done. I just got mine done yesterday and I couldn't be happier. It took one day to repair and the car runs so much smoother, I noticed that the engine idles much better than it used to previously and the startup noise is eliminated. Do not listen to anyone who says they have to take off the heads to do this repair! The repair is detailed but not that intrusive. They have to take off the valve covers and cam gears but it's not dismantling the entire motor like i've been told previously. My dealer was able to replicate the sound easily and fixed it per the tsb no questions asked. I felt very comfortable knowing my tech owns an 08 is350 and has done this repair on his own car himself. Funny thing is I started to ask him a ton of questions. I asked him about the fsport intake and he said he had it on his car for a week and took it off as it was a piece of junk that made his car sound like a honda. He told me to just replace the pipe and leave the airbox alone.

***Update***

After having my car for no more than 24 hours since the engine work was performed I noticed an unusual amount of exhaust gases exiting from the tailpipes. Sitting still the exhaust would build up a small cloud behind the car. After further inspection there is exhaust soot all over the rear bumper with a bluish tint to it, i'm assuming oil. Also my tailpipes have a large amount of rust on the inside which was not there prior to bringing it in for engine work and the tailpipes themselves are corroded on the outside. Not sure what happened but something was obviously not put together right. It's back at the dealer right now and has been there for nearly 3 days. I'm going to make sure they clean the tailpipes and also check/replace the catalytic converters. With that much burnt oil coming out of the pipes I couldn't imagine it doing any good for the cats!

I would be interested in another update justflyin83. Do you regret getting the maintenance done or did the dealer resolve your issues after the so called fix was done. I too have an 06 IS350 with the same issue as everyone else on this tread. After reading all the posts to date I am still undecided as to whether this repair is worth it or not. I would still like to know from someone "in the know", if damage is being done to the engine when this rattling noise occurs. I can't imagine it's not, from the sound it makes. The randomness of it is very confusing.
I cringe at the thought of my engine being opened up, I read the entire TSB, and it is a pretty invasive procedure. I agree, once you open up a factory built engine, it's never the same. I am going to monitor this thread for awhile before I take the plunge. I have 35000 mi. on my car, so I have plenty of warranty left, my only concern again is, am I doing damage to this engine or not.
Rickaokc

Some of the guys on my.is had it done. I've never had the noise on mine.

http://my.is/forums/f126/

I absolutely do not regret having the work done on my car. The noise does not do any damage but it's a noise that is unacceptable for any car let alone a Lexus. I did post an update stating that I had excessive smoke coming from my tailpipe. It was just residue that was burning off from when the worked on my car. It actually went away within 2 days. The car runs and sounds perfect. It actually idles and runs much smoother overall.

First off let me clear up a forum myth on this procedure. They DO NOT open up the motor to do this. All they are simply doing is replacing the cam gear which requires the partial removal of the timing chain. If the head is not lifted than are hardly call this opening up the motor. They do not even drain the oil to do this procedue, that should tell you something in itself.

Overall it's a simple fix that should be done by anyone who is experiencing the noise.