I am 100% aware of the carbon issues that the IS250 suffers from and fortunately my car has already gone through lexus to get my engine rebuilt at 68k. 60k miles later, my car at a good 126k has been having a rough idle. Did a little maintenance and I pulled the intake manifold to only see the carbon issue just as bad as the first time. Symptoms aren't as bad to warrant to go to the dealership but anyone have any ideas or removing or reducing how bad the carbon currently is.

Ive done sea foam but doesn't a few thousand miles ago but does not look like it helped as much as i wanted it to.

Things I am aware of:

• Lexus Carbon Buildup Recall
• Catch Can to reduce oil and carbon recirculation
• Redlining engine to break down some stubborn carbon

 

Walnut shell blasting of the intake is the only true remedy that I have seen.
The bmw guys have this done for their direct inject engines as part of their maintenance. Why is there only one shop offering this service to our 2006-2010 is250's? Anyway I found a shop that would do it for me. Will have it done by the end of the year. My pistons and rings were replaced at 60k I'm at 90k now. Find a bmw shop that offers walnut shell blasting and see if they will modify an attachment for the lexus ports.