Lexus IS250 4GR-FSE Engine Carbon Build-up (merged threads)
#481
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I own an IS350 (port injectors) and I have the carbon build up issue, which makes itself known every day. I know that IS350's aren't represented in this thread too well, due to having port injectors, but I'm one of the few that is experiencing this problem. I have had a top engine clean completed by Lexus and have added fuel injector cleaner to 2 tanks of gas over the course of a month, but the rough idle remains. If the rough idle issue doesn't stem from carbon build up, I'm at a loss.
As far as the 250??? I have an 07 w/56k.. I've done the top engine clean in the shop, I had extensive buildup... nothing you can do about it... It's got nothing to do w/EGR, its the PCV system in the car. Down side is, If you plug the manifold port for PCV and you vent it to a breather... you'll get a system lean code on both banks... I did the top engine at 30k, Im going to take it apart again at 60k when I do plugs... this time if needed im running top engine clean & then washer fluid... I will post pics before & after, I've done this to a RX300 w/crazy ping with excellent results
#483
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
nah, the top engine clean wont bring on other problems... while it does remove a decent ammount of carbon buildup, it doesnt do as good of a job on the gunk built up on the valve stems. I can guarantee you that from doing atleast 30 or 40 of these already... I'm going to try a diff method, I hope I can bring you all good results on a home made version of the TSIB
#484
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
So for the 2nd time I had the blinking CEL, Check VSC, studder problem happen. I had this previously and in the end the dealer performed the "cleaning" under the TSB. I am now at 61K miles (but it is a CPO) and my question is - is this still covered under my warranty since the "fix" did not work the first time or will I need to pay for the cleaning?
#485
Lexus Champion
iTrader: (9)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
^^^ take it back to them.. i actually just took mine in today because my car while driving around 15-20 mph just suddenly lost power like it was gonna stall then my check vsc light and check engine light came on. Took it into the dealership and as long as that is the issue its covered by the warrantee of 6 years or 70,000 miles so you should be good but might be different since they have already done it once.
#486
Driver School Candidate
Join Date: Oct 2006
Location: CA
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
i had this problem on my 2007 IS250 happened like 10 to 12 times. took it back to the dealer each time, kept the paperwork. before my warranty expired (when they would they have stopped covering the top engine clean procedure) i returned the car as a lemon.
#488
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Let's see how long this fix lasts.
#489
Driver School Candidate
Join Date: Oct 2006
Location: CA
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
and that was the problem with my car... every time the dealer would do the top engine clean, the issue would go away temporarily. then after a few months or weeks, it would come back. they even replaced the valves on my car but the issue always returned. if you kept ur paperwork and went in multiple times, it might be worth it to speak with a lemon law lawyer just to see what ur options might be.
#490
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
and that was the problem with my car... every time the dealer would do the top engine clean, the issue would go away temporarily. then after a few months or weeks, it would come back. they even replaced the valves on my car but the issue always returned. if you kept ur paperwork and went in multiple times, it might be worth it to speak with a lemon law lawyer just to see what ur options might be.
#491
Driver School Candidate
Join Date: Oct 2006
Location: CA
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
yep, my dealer did indeed have to replicate it for them to work on it. in my case, lexus would hold onto my car for days at a time and each day would try a few times to replicate it. the problem would eventually occur and then they would do their top engine clean.
#492
Driver School Candidate
Join Date: Jun 2011
Location: MO
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I would like to know who actually has pulled the valve cover to verify the problem and at what mileage? It can also be a problem with auto's and sensors. It's common for auto's to hesitate under certain circumstances due to slow responses. It can also be caused by the ecu going rich/lean going from load to decel. On decel, most newer engines actually cut ALL fuel and use drivetrain to keep the motor spinning.
If it is what many are stating, it is what they call pinging. Maybe many have some kind of vacuum leak?
I cannot imagine a car with 20k having much carbon build-up. Although, the compression ratio is very high and can be causing excessive crank case pressure. I would not suggest nitrous, but maybe install a very small water injection system in the intake? Find the smallest nozzle you can and keep running WI. It cleans good or maybe even a 50/50 injection with methanol. That will stop the pinging, clean the engine and give you a little boost of octane.
I never would have though a toyota would have this problem at such a low mileage. Toyota's trying to be on the cutting edge of efficiency since late 90's, but that causes problems. They used to worry alot more about reliability and over engineered EVERYTHING. My corolla has 243k on it and runs great, even with burning 1/2 quart every 3k. My mr2 has over 240 whp and holds up fine to abuse. Newer cars are just not built the same. They want more mpg and are sacrificing reliability. Toyota isn't the only one doing this.
If it is what many are stating, it is what they call pinging. Maybe many have some kind of vacuum leak?
I cannot imagine a car with 20k having much carbon build-up. Although, the compression ratio is very high and can be causing excessive crank case pressure. I would not suggest nitrous, but maybe install a very small water injection system in the intake? Find the smallest nozzle you can and keep running WI. It cleans good or maybe even a 50/50 injection with methanol. That will stop the pinging, clean the engine and give you a little boost of octane.
I never would have though a toyota would have this problem at such a low mileage. Toyota's trying to be on the cutting edge of efficiency since late 90's, but that causes problems. They used to worry alot more about reliability and over engineered EVERYTHING. My corolla has 243k on it and runs great, even with burning 1/2 quart every 3k. My mr2 has over 240 whp and holds up fine to abuse. Newer cars are just not built the same. They want more mpg and are sacrificing reliability. Toyota isn't the only one doing this.
#493
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Its not sludge, pulling the valve cover wont reveal anything.... they're all clean. It's not related to any sensor, lag, ECU, fuel cut, vacuum leak or pinging. at 20k its not that common but they do build sufficient carbon and sludge behind the throttle plate, lower intake manifold runners and valve stems to cause idle roughness.
The water injection is ideal, but you're totally wrong about the reliability factor. Aside from defective intake cam gears and carbon buildup, there's nothing wrong you can find mechanically with them.. you want to talk reliability??? ask BMW what they're doing to recall all the straight 6's that are suffering from shearing cylinder head bolts..... now thats a damn failure
The water injection is ideal, but you're totally wrong about the reliability factor. Aside from defective intake cam gears and carbon buildup, there's nothing wrong you can find mechanically with them.. you want to talk reliability??? ask BMW what they're doing to recall all the straight 6's that are suffering from shearing cylinder head bolts..... now thats a damn failure