Crystal

Right now I'm driving a Mercedes SL500 until I decide what I want to buy. I'm fortunate that my dad had an extra car that he's letting me drive while I make up my mind. It's definitely no sweetheart on fuel though. Not at all practical for a daily car.

I really liked my IS, just not sure I want to tempt fate and know there's the possibility I could have the same issues again.

chikoo

SL500? $$$$$$$ when you are in that car, you cannot worry about mileage. LOL.

SteadyEd

HI all- I have a 2009- is250 awd, The check engine light has been coming on for the past 6 months- The dealership has had it in and out of service 4 different times- 1st- they said it was carbon build up on the engine- they had it for a week at that point- The after a few days when i got it back - the light came on again - 2nd time they said the engine needed a top cleaning- they it- and sure enough 2-3 days later the light came back on again- the 3rd time- They changed the spark plugs and a few other things- gas cap ect.... NOW they have my car again- its been 3 weeks-

They are saying its a fuel pressure issue- They are faxing reports to a tech in California- to figure it out- The Service is telling me- " The car is in the final stage before they call Corporate to get he ball rolling on the Lemon law and give me a new one-

Can Anyone out here tell me if they have experienced anything like this with Lexus? I am completely frustrated and disappointed-

Thank you
Ed

SteadyEd

HI all- I have a 2009- is250 awd, The check engine light has been coming on for the past 6 months- The dealership has had it in and out of service 4 different times- 1st- they said it was carbon build up on the engine- they had it for a week at that point- The after a few days when i got it back - the light came on again - 2nd time they said the engine needed a top cleaning- they it- and sure enough 2-3 days later the light came back on again- the 3rd time- They changed the spark plugs and a few other things- gas cap ect.... NOW they have my car again- its been 3 weeks-

They are saying its a fuel pressure issue- They are faxing reports to a tech in California- to figure it out- The Service is telling me- " The car is in the final stage before they call Corporate to get he ball rolling on the Lemon law and give me a new one-

Can Anyone out here tell me if they have experienced anything like this with Lexus? I am completely frustrated and disappointed-

Thank you
Ed

iRock

iTrader: (12)

Yea looks like you have a similar problem as crystal... lex might have to buy ur car back

bailem2

Crystal et al,

I own a 2006 Lexus IS 250. I'm a pretty well experienced and well equipped mechanic, and my wife drives the car daily. The vehicle now has 130,000 miles on it, and aside from this issue, the car has been excellent by any measure.

When the vehicle had 5,000 miles on it, we were driving down the freeway, and the SEL started flashing, and it was obviously running on 5 out of 6 cylinders. I pulled over, turned the car off, restarted, and all was fine with the service engine light (SEL) illuminated. I drove to my shop, plugged it into the computer, and it was P0306 - Cylinder #6 misfire. I scheduled an appointment at the dealer the following day. They pulled the same code, swapped coils and gave it back to me. That's reasonable, and probably just what I would have done. This happened every few months at 15k, 22k, 38k, 55k, 65k, 85k, 115k, 125k, and a whole lot lately. When it was under warranty, it went in every single time to document the problem, and they couldnt' reproduce it. The misfire was stored, but it wouldnt' happen again for months. After it got out of warranty, I brought it to the dealer at 85k, and atain at 126k. I can tell you that it's not necessarily 1 culprit cylinder, it moves around, but mostly #4 and #6, the two rear-most cylinders. Switching coil packs does not identify a particular coil pack that's causing the problem. While in the beginning, pulling over, turning the car off and turning it back on solved the problem, in the last year or so, it's taking multiple restarts to get the car going again, and lately, it's been more and more. Just today, my wife was stranded on the side of the road, and is getting towed as we speak. Restarts will not solve the problem.

One time around 90k, it acually happened when I happened to have a OTC Genesis diagnostic computer sitting in the trunk. i pulled over, and plugged it in while the car was still running on 7 cylinders on the side of the road, and I could see the misfires climing constanly consistent with a dead cylinder and the stumbling feeling. Fuel pressure looked good, and none of the other values stood out as a potential cause. I turned it off and on again, and all was fine.

As for theories...

The fact that a restart solved the problem, that would SEEMS to indicate an ECM related issue, either with one of its sensor inputs or with the software itself. It is, however only a guess. Something changes before and after the restart. P030X is a performance DTC, so it's not a matter of a sensor indicating a value out of range, so it's not as simple as easily diagnosing a bad sensor.

I don't have updated valve springs, however I have heard of others having their springs changed with redesigned springs. I'm not sure if they had 350's or not, but I have seen them on the boards. The dealer has not suggested this, so I assume it's not a factor. There is a TSB released in the last year about flawed rings causing issues like this, and the fix is new pistons and rings, and if the block is scored, a new block. In a case like that, the most cost effective option is to put a used motor in the car, which I'm prepared to do myself, if someone can tell me that's the case, but they can't. Motors go for around 2k, and I can accomplish the swap myself, but if the cause is electronic, then that's a lot of money for nothing. I'm not about to guess.

When it was out of warranty, I brought it to the dealer because I felt that the best use of resources was to take advantage of a shop who would have likely seen an issue like this before and solved it., but that does not seem to be the case, and they claim they haven't seen an issue like this ini the past. Tons of misfires cured by a top engine clean or induction service to remove carbon from valves found to cause low compression is very common with this motor, however I have performed several top engine clean procedures and induction service, and have pretty much ruled out carbon buildup. Any misfire MUST be caused by one of three things - fuel, ignition, or compression. Today, it's happening constantly for the first time, so I'm going to attempt to plug the computer into it, identify the cylinder and check fuel pressure (which the computer can easily tell me) and compression in the dead cylinder. If there is low compression, I can tear the motor down and figure out why. If there is plenty of compression, then I would attempt to identify whether or not the plug is firing, but I'm not yet sure how.

The worst part of this is that if you drive it was a dead cylinder, then it may be dumping fuel into the exhaust, which will shortly destroy the catalytic convertors, which are extremely expensive.

This is a mystery, and I have been trying in earnest to troubleshoot this for years to no avail. In defense of the techs at the dealer, there isn't much to go on without tearing the motor apart, and that's obviously tough to justify at this point. It has been happening since the car was brand new, so whatever the issue, it's been pretty consistent throughout the life of the car, only it's difficult to reproduce, and can be weeks or months between occurrances. Until recently, it wasn't a deal breaker as at most a few restarts were all that was required to remedy, however now that my wife is stranded, the calculus has definitely changed.

Hopefully, this will happen consistently, which should aid in troubleshooting. It sounds as if the issues are very similar.

Regards,

Michael D. Bailey

juvi22003

iTrader: (2)

^ good write up, one of my IS is currently at the dealer right now i brought it in for carbon build-up, they called me a few days later and told me one of the cylinder was misfiring and they will replace the piston. Not sure if they will be replacing one piston or all of them. I originally brought it in because of high idle and stalled a couple times.

photoman21

Hard to believe that this is still an issue and Lexus is still scratching their head.

My wife had this same issue two days ago (#1 cylinder on a 2012 with 25,000miles) and drove directly to the dealership. They claim they can't replicate the issue and gave the same list "possibilities".

I hate to say it, but I think we're going to get rid of the car before the warranty runs out. Damn shame, we love(d) the car.

autox250

running it with a misfire will NOT cause catalytic damage, the car is smarter than that. Why does the car run fine after you restart it?? Because when it detects a misfire for a period of time it shuts off the individual injector to prevent cat damage until you cycle the key.
As far as your '12 misfiring, if it IS carbon... the bulletin goes up to some 2010's. It's important to see other parameters along with the misfire, there's a misfire log in the ECU where you can see past history. Also there's a snapshot of all engine data when a code is set.
has it happened again??

Luc2

My IS250 AWD 2009 just started to misfire on cylinder one. It has less than 60 K miles. One morning when the temp was 28F , when I started the engine it misfired and stopped, a few times. Few days after I saw on my INNOVA OBD@2 model 3100e the code P35001 saying "Misfiring on cylinder 0ne". I always used the best oil brands and only synhetic. The oil change is every year or after 10K miles. The gasoline is always over octane 91 mostly from Esso.
Questions:
1- Is it possible, the problem comes by the fact that I drive short distances most of the time (less than 5 miles)
2- I drive in "economy" mode, can it be affecting the carbon build-up, if any

I resetted the checked engine code , using my tester , It showed "Cylinder 1 misfired". Following that, I stared the engine and put the switch to "performance" and drove 15 miles revving up many times above 5500 RPM. without any misfire, What amazed me is the RPM has for years not been as stable in winter time as it is now.The temperature was 28F when I drove at high rev . Should I keep it in "Performnce" mode all of the time.?
Thanks for your help

Any suggestions, how to handle this problem, and avoiding to spend money for nothing ?

MikeFig82

iTrader: (13)

If you suspect carbon build up. Have a look here on how to test.

https://www.clublexus.com/how-tos/a/...mize-it-367282

Definitely short commute will have a greater impact on carbon build up. Since you're at 60k miles. I'd suggest to do a spark plug, and PCV valve change. While at it inspect the carbon build up on the valves themselves.

primavera

Basics first
Swap the coil from cylinder #1 to a cylinder next to it. Clear the check engine light. Start the car and see if CEL comes back. Scan for new codes. If misfire moved to another cylinder, you have a bad coil.

See the video around 6:00 minute mark

Luc2

is adding to the gas SEAFOAM (automarine fleet) still a good idea , as recommended on your previous link ? if not are there better products ?
Thanks

Protholl

I use the Shell version and it has worked well. If you have an epic amount of buildup from skipping oil changes you may have to go down the walnut blast route. Before you do that try this:

https://www.stp.com/product/pro-seri...valve-cleaner/

Luc2

Thanks a lot for the link. MY 60K miles 2009 has mostly been driven short trips, all seasons (canada with -20F regularly in winter) with ride less thn 5 miles mostly in town, driven at low speed up to 45 MPH. I suspect this is part of the problem.. As I mentionned before only synthetic oil every year, and high quality high octane gas (93 octane or better)