ToreOe

I just returned from the dealer after my ECU update. Took the long way back to test different driving conditions. My impression is that this update does not fix anything. It does, however, avoid the condition where the vibrations occur simply by running the engine at slightly higher RPMs. While this change surely did motorway cruising less annoying, the vibrations are still there every time the engine passes 1300 rpm when I drive slightly more spirited and when the ICE starts up during driving. I spoke to the salesman and told him I will be going to ask for them to take the car back if this problem is not fixed reasonably quick, something he did not protest to. They will take my car in for a throughout inspection next week though, particularly since the vibrations got so much worse after they replaced the bushings holding the diff. Looks like I'll be driving the GS again... -Tore

Now this is interesting. I am going on my weekly complaint-trip to the dealer tomorrow, and I would love to hear you first impressions on the new ECU software! -Tore

Well, I've been given a fully loaded GS300h F-Sport the two times my car has been in (diagnosis and then repair). It's decent, but the IS is a lot more fun. The vibrations have definitely gotten worse after the repair. We were going on a daytrip this weekend (3 hour drive each way), but turned around after 20 minutes, drove home and switched to the Prius instead. It's that bad. We have very consumer-friendly laws in Norway (significantly better than the EU) and if Lexus does not succeed fixing this rather fast, I will probably stand a good chance of returning the car and getting my money back. No that I want to, though. The car is built-to order (4 months waiting), and I have put in quite a lot of work getting it how I want. (Installed trailer hitch, Defa Warmup heater, GPS tracking, hidden dash-cam etc). -Tore

Well, got the car back from the dealer today. The mechanic called me and told me he was sorry, but changing the differential bushings made no change to the vibrations at all. Driving the car back home, I must say the mechanic was wrong. There is definitely something different. The vibration is not as loud, but over a wider speed range (audible from at least 60km/h), and over a wider RPM range (1200-1700). I am unsure if it is an improvement or not... They had found that one of their demo cars - an F-Sport - had the same vibrations, and would do further tests and repairs on that one. Promised to get back to me next week. I had a GS 300h as a loaner these two days, and I would definitely say I could feel the same vibrations in that car too, but they did not "resonate" like in the IS. Thus they were barely notable. To add to the disappointment, they had managed to get a dent in the driver's door of my car. Very visible on a black car. Now the car needs to go back in to repair and repaint the door too... Will keep you informed on any further development. -Tore

Hi all, I've had my IS300h Luxury for 2 months/3000km now. The car had the vibrations described in this thread from day 1, although veery little from the start. It has gotten gradually worse, and last Friday I went to my dealer about the issue. The mechanic that checked the car was able to reproduce the vibrations, and told me he it was a known issue on the GS. The problem there was the bushings holding the rear differential. Lexus had produced a new variant of these bushings, that removed the vibrations. Now, since the GS450h and the IS300h uses the same rear diff and the same bushings to hold it, he was going to replace the bushings on my car with the upgraded ones for the GS. The car will be going in Thursday - it is a two day job. I'm crossing my fingers! Tore Sandnes, Norway