domnf15

What have your oil change intervals been and what kind of oil did you use? If it's throwing misfire codes for the same reason as the older models you could have bad piston rings and/or pistons. Do or get a mechanic to do a wet and dry compression test on the cylinder that throws the code. It could also be fuel delivery, like the injector or some other part of the electrical system. You said you changed plugs and coil packs, how about the wire set itself?

MxdMenace

Oil changed at recommended toyota intervals (8000kms)
Coilpack assembly does not have wires

Update - Dealer removed intake manifold assembly to inspect valves. Low and behold carbon build up on the intake valves spotted. Dealer is removing the head for further inspection but it seems like this is all covered under my powertrain warranty. The money spent on coilpacks and plugs is being refunded (hopefully). Will give details once I get more news this week.

speed_Demo

It's cover within the sales date of the vehicle, up to 9 years. Meaning as long as within 9 years, and 364 days!! However, the dealer will need to test the vehicle to replicate the engine shake/rough idle. I recommend you try to replicate the problem on your own before bringing it to the dealer. Or if your vehicle generate a code, then you might be good.

Good luck!

Arrta

For those of us who have the carbon buildup and have been abating it with sea foam treatments..
Valvoline has a service called EasyGDI that is supposed to help with this by treating the issue with their own intake spray treatment.
Not sure if anyone has heard of it before, but it is detailed here : https://www.easygdi.valvoline.com/
I called my local Valvoline Instant Oil Change and they offer the service for $75, and reportedly it can be done in about 15 mins.

MikeFig82

iTrader: (13)

It needs to be done through the intake air stream. Doing it through the fuel will net 0 results. The fuel never hits the back side of the valves. Seafoam, or CRC does work. I'd probably get the CRC GDI cleaner first though. Heavy deposits will require multiple times done to make it effect. I think the best spot to run it. Is through the top capped line next above the purge valve. You want the fluid to make it to all 6 ports.

liamlexus250

I been using my is250 for a month now and every time I start my car it sound a weird rattling sound. can anybody help me figure a fix for this?

domnf15

If the noise isn't just the fuel injection system, it could be bad VVTi gears. I don't think the IS250 engine is known for that but it also depends on your oil maintenance. If you want a good explanation go to YouTube and search for "car care nut VVTi rattle".

Yodog

isn’t this the cam gear (exhaust or intake?) ?