Lexus IS250 4GR-FSE Engine Carbon Build-up (merged threads)
#1142
The easiest way to find out would be to take an affected IS250, give it BG44-K can in the gas tank, and see if the problem goes away. If it does, then it works. Else not.
#1145
GDI depends on fuel being sprayed on and reacting off of a specific spot on the piston. A layer of carbon would change the geometry which might result in changes in combustion?
None of us have the resources necessary to apply the scientific method and determine the real, provable root cause(s).
I wonder how much more it would cost Lexus to add D4-S to our cars (reprogram, swap heads and manifold, add injectors - whatever) than it costs to swap pistons and rings and not have truly fixed the problem...?
#1146
So I got the car back today. Looking at the invoice they noticed major carbon build up. They performed the top engine clean and cleaned all carbon from the valves. They also changed the oil. No issue with the drive back from the dealer to the office and then from the office to home. it's to early to tell though. They did notice a vibration from the rear transmission engine mount and are fixing that under warranty in a couple of weeks.
Glad they have extended the warranty on this as my car will be 6 years old in another six weeks.
Glad they have extended the warranty on this as my car will be 6 years old in another six weeks.
#1149
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'06 is 250 (~108,000 miles) in for brakes n tune up. Noticing its I direct injection I looked for carbon buildup while I had the plenum off for plugs 4 & 6 .Sure nuff it was loaded on the backs of the valves. Reading the top engine clean TSB it cleans the cylinder but not really the valves. I rotated the crank to close the appropriate valves and filled intake runner to just over carbon n let sit till dissolved and blew out with air and rags while spark plugs were out. Put some oil in each cylinder , blew it around lightly and reassembled. After some smoke and a little noise runs great. P.s.. make sure no liquid is left in cylinders except for a thin film of oil . No puddles. You'll wreck your motor .
Last edited by RONNIEJNZN; 09-07-12 at 11:30 AM.
#1153
So I just got this done due to the rough idle issue. Now I don't know if I was lucky or if the dealership (open road lexus richmond) was just doing their job right. I booked an appointment for them to check the car.
The tech took my car for a drive with me in the passenger seat. I explained the issues and just mentioned rough idle at lights and stop signs once in awhile. I never mentioned any error codes popping up. Went back inside and the SA asked the tech what was up, He mentioned rough idle and to check for TSB's.
Booked an appointment 1 week later, got a courtesy car for 2 days because "they wanted to make sure the job was done right".
Top engine clean done plus oil + filter change. No questioned asked. Excellent service.
The tech took my car for a drive with me in the passenger seat. I explained the issues and just mentioned rough idle at lights and stop signs once in awhile. I never mentioned any error codes popping up. Went back inside and the SA asked the tech what was up, He mentioned rough idle and to check for TSB's.
Booked an appointment 1 week later, got a courtesy car for 2 days because "they wanted to make sure the job was done right".
Top engine clean done plus oil + filter change. No questioned asked. Excellent service.
#1155
I got the CEL/VSC light awhile back and autozone scanned it as p0051 A/F O2 sensor bank 1 sensor 1. So I went and bout the the O2 sensor and replaced it but the CEL/VSC is still there. I have experienced the rough idle numerous times so maybe the CEL/VSC is triggered by the carbon build-up but throwing an O2 sensor code?