OneJay

iTrader: (14)

Hi all,

A buddy of mine has a 2016 IS200t and has been having issues with something boost related. Here is how he describes the issue.

Has anyone else had an issue like this? I'm thinking it sounds like a boost leak, either from the bypass valve or somewhere else on the plumbing. Any other suggestions?

Thanks so much!

E46CT

Interesting. I'll have to drive mine today and see if it does that. Let us know the outcome

Ray20213

mine has been doing that for a few weeks now I just thought it was normal?? I didnt bother checking anything

Ray20213

Are you still running stock exhaust? Because I noticed mine started doing it after I installed my aftermarket exhaust

brendanf

What is max boost on the 200t? Is it possibly a boost creep issue and the ECU is trying to correct it?

GTO714

Hey Ray, it's my car. My buddy got the thread started for me. This one is bone stock except for the tinted windows. So that's why I'm so frustrated that this is happening to the car. Usually I have myself to blame for a car issue because I changed something. But this car I can't even recall if I had popped the hood on it except for while I was at the dealership.

brendanf

If everything is stock and never been touched, assuming all hose clamps are tight and such I could see 2 possible scenarios...

1. The PID that controls the boost (software) needs to be adjusted which is something only a software engineer from Lexus would be able to do
2. Maybe there is some carbon buildup in the exhaust outlet that is causing a restriction, which in turn would cause a higher velocity exhaust, making the turbo spool more..

Pure speculation by me though...

Ray20213

Hmmmmm well I haven't put much thought into this as I stated before but I guess I will have the dealer look at it Thanks for the feedback if you have any thing further and figure it out please post and let me know and I will do the same thanks

CarlitoIS

I haven't noticed this. I'll see what mine does tomorrow. Does the car feel laggy or anything or is it just sound and the boost pressure going up and down?

Ray20213

car feels "regular" until i really get on it from a dead stop and then you can hear the turbo boost fluctuate and yes it feels a slight lag very strange

Ricoo

I'm having boost issues as well. First issue, my car was bottlenecking if you will. I had the pedal all the way down but for some reason my car would not go above 75 mph. From a stop, my car would drive as if it was in 8th gear. These two issues have only happened once. Another issue I have is over boosting. The boost gauge is maxing out quite frequently. Today on the highway, I was cruising at 70 mph. Punched the pedal and the boost gauge immediately hit the redline before I could even reach 75 mph. It does the same thing at lower speeds.

AMNss

Do you have any performance issue? If it is only sound fluctuating with out jerking it could be the rattle snake effect which is normal. However if there is a real performance issue then you could have a defective bov, or ECU issue or leaks from hoses.

brendanf

Does anyone know if Lexus used a variable geometry turbo?

I'm am starting to wonder about 2 more possibilities

1. Sticking wastegate.
2. The actuator that controls the VG is sticking.

I've seen 'fluctuating' boost only on diesel generators but again, it is usually a result of a bad PID setting (generators run at a constant RPM).

E46CT

Yeah good thing I haven't modded mine. I'm keeping it bone stock for a while to see how this new powertrain does. Imagine something happens that would happen anyway but now because I have an intake or other mod, they blame it on that. No way jose!

Seems the NX200t has been problem free though.

I hope Toyota did their homework when designing this engine. I know its new territory for them.

corradoMR2

NX has no issues reported with the engine BUT from the way some of you are describing the jolt/fluctuation, it happens too with the NX. That's because the traction control/VSC kick in too aggressively to pull back boost on full throttle input from a stop or low speed turn, until the system thinks traction is regained and allows for the full boost/power to engage. BTW, boost can reach a max 17 psi, comparable to the German offerings which is pretty impressive for a stock turbo engine where focus has been reliability in its engineering above all else.