What causes carbon build up on the intake valves?

-poor quality fuel
-bad driving conditions (short distance, in cold weather, not letting the engine warm up, 0w20 oil and long oil change intervals)
- When using a catch can in my other car (mazda 6) I've noticed that the catch can was empty when using 5w30. A fair amount of blow by was noted using 0w20. If you consume oil, will make things worse.

How to fix it?

- Add fuel system cleaner to your tank
-Drive 30 minutes on the highway at least once per week, if possible
-take it out on the highway when fully warmed upand do 3 full throttle pulls to near redline one after the other. The first pull will get the intake ports hot enough, then, after that, most of the carbon should burn off easily

 

Who is this troll? (Oops, did I post this out loud?)

 

MODS are asleep; post garbage /S
@IB Jason MODs can you block this user? they are posting empty threads and useless info, they just got an account for that reason

 

Carbon build up is about the last thing I worry about in this engine (2GR-FKS).

 

On the IS250 the fuel never hits the valves on DI engine. It will probably work on the IS350 DI, and port injection.

 

This guy has been posting the same thread in multiple forums

 

I thought the IS250 is both port and DI. In any case. some buildup is always invetiable, regardless of injection design. Mainly depends on your driving style.

 

What the hell? I was just trying to start a discussion. I find your post specifically far more useful than anything I have posted myself for that matter.

Carbon build up can happen to any engine, depending on driving style. obviously with a good design like Toyota there won't be much, but you can't just avoid it completely in other places within your motor, even if you have port injection.

I was also mentioning using fuel system cleaner, which is very helpful.

 

Majority of the cars that suffer from buildup are cars that have direct injection injectors, the 2006 gs300/is250. The injectors do not wash the intake valves like a regular conventional engine does, so that carbon builds up on the backs of intake valves. The best way to clean them is by using chemicals through the induction/intake manifold. Every 40-50k miles a combustion cleaning would help performance and fuel economy.

Youre correct that cars that a babied build more carbon, but also cars that are abused fall apart. Im somewhat easy on my car but at times on the highway I will blow the cobb webs out of the engine.

 

He is also on another thread titled 60k transmission flush. There is no question either.

 

OP... 58 posts in total... all today... on 17 different threads you started in IS, ES and GS Forums...? That kinda is the definition of trolling, no?

 

This really sounds like a scammer, trying to get his/her posts count up so they look "valid". Why would you copy and paste THE SAME THREAD to each and every forum?

 

I think you guys are seriously overreacting.. I mean, I wanted more people to see, and try to start some sort of meaningful conversation about things that are less boring. Why is everyone freaking out?

 

Your intentions may be good, but it typically raises red flags when a new poster comes in and creates a bunch of new threads, most of which had a title but no content. I'm not sure what your point was in creating so many empty threads.

 

True, but modern DI motors have come a rather long way compared to even a decade ago. For example Mazda with their newer skyactiv engines has rerouted the coolant passages away from the intake ports. which obviously increases temperatures in that area. Once you get the intake valves to 400F or so from a bit of hard acceleration, nearly all of the carbon is burnt out. When i'm doing a full throttle pull in that car after thousands of miles of normal driving the smell coming from the exhaust is extremely strong/pungent. I can literally feel the engine pulling better and smoother at low RPM's after that. Simple method, but it works.

To be honest, You can abuse a car all it's life so long that you avoid doing so in the first 3000 miles while the drivetrain is still new, keep up with maintenance religiously and it's very unlikely you will run into any issues. Hopefully most of us are past that stage, but one could only hope.

As a general rule of thumb, one full throttle pull close to redline per week is absolutely going to do more good than bad for your engine.