Hello guys, I know that direct injection suffers from carbon Buildup and I know that both GS300 (06) and IS250 engines suffers a lot from that, but, does GS350 have this problem?

If yes, ways to prevent or clean?

if not, why? What did lexus implement to avoid it on the 2GR-FSE?

Please share your knowledge and tips on the topic keeping our engines clean.

Thanks in advance!!

 

It not common on the 2GR-FSE. Lexus added port injection on the 2GR-FSE. It has the best of both worlds. Direct Injection into the cylinder and Port injection in the intake stream. That will wash off the carbon buildup on the back side of the valve.

The 3GR-FSE and the 4GR-FSE only have direct injection.

 

Hey thanks for the info, didn't know this engine features this technology, quite interesting! Probably not a lot of engines cone with this two types of injection.

Now wondering what's the disadvantage of having the two.

 

Probably expensive to replace. If the direct injection system goes out, the port injection system will take over and vice-versa which will cause reduced performance. The system is meant to work together but also has a built in fail safe in case something like this does happen.

A lot of the newer Lexus, minus the ES, CT, GX, LX, will have both DI and port and Toyota started to introduce them on some refresh models like the Highlander and Tacoma. The FR-S/86/BRZ also had DI and port. I'm not sure if anyone else outside of Toyota\Lexus has the D4-S system. Maybe Infiniti.

Mazda new Skyactive engine is only a DI system but they use an ultra high compression to burn off the carbon build up.

 

You can run seafoam through the intake manifold via the blank vacuum nipple. I ran two bottles on my warm engine and that made the engine run way smoother.

If you plumb in an oil catch can this would be better at protecting against carbon. As oil vapors from the valve covers get rerouted through the intake tube and circulates to get burnted off, but some of these oil vapors turn to carbon.

 

Can you show me a pic of those vacuum lines you say?

 

The top engine cover pop right up, and in the back driver side is a vacuum nozzle nipple with a rubber plug on it. get a small section of hose with that same size as the plug.

With the engine hot from driving, trickle pour the seafoam into the engine with the engine running. Do not pour too much that the engine stalls and shuts down. Pour 1/4 of a bottle and then turn off the engine and let the chemicals soak for 15 min, keep repeating this step until you finish a complete bottle. I used 1.5 bottle on mine and created lots of smoke and check engine light turned on but in the end it ran very smooth. Also if your plugs are old this is a good time to replace them after the cleaning. The toyota dealer many will do top engine cleaning using BG chemicals thats good to run aswell but the diy seafoam is cheaper and faster imo.

 

I have been getting a stumble and hesitation while accelerating, and with 155XXX miles on it I'm not sure the valves have ever been cleaned. so over the weekend I actually removed the intake manifolds and cleaned off all the carbon build up on my 06. It was bad. I should have taken before and after pics to post but i wasn't thinking. It took me something like 5 hours to clean all 12. I haven't noticed an increase in fuel economy yet, but performance has improved

 

How did you clean the valves what chemicals did you use?

 

 

Nice thats a good way to remove it! Have you thought about treating the piston top and soaking the oil rings aswell? Im sure access would be easy through the spark plug holes, those GS300's are notorious for carbon clogging there rings.

 

Audis run the combo of of DI and PI as well after they had massive carbon buildup issues on their 4.2L V8s. For many S5 owners it is a must to have the vlavles cleaned every 30K or else the engine will die.

 

I've been thinking about it, but I'm not sure what to use... suggestions?

 

Berryman parts clear is very good to soak into the pistons. You can also try 50/50 atf fluid with acetone! Whatever route you chose, I would replace the oil after letting it soak overnight. Also good time to replace the spark plugs

 

I've never heard of a direct injection system fails in a car. At least never in a lexus.