lexo98

Did you check for mice? :D Now as retarded as this is going to sound I had the same problem. It turns ou when I accelerate the pebbles in my head rattle. Hence, the noise. Seriously though I had low coolant that trapped air in the system and when you accelerate the water pump pushes coolant through what I think is the heater core behind the dash. Top off your coolant and make sure you don't trap air in there..

Does anybody with experience driving on tires that are the same model and size, but different speed ratings have a comment?

I keep trying to reply so sorry if there are multiples. It is possible that you have an air pocket. I've been there. If your radiator was really low or empty when you filled it that may have caused it. Try this. With the engine completely cold take off the radiator cap and start the car. Within a minute or so if you had air you will notice that the radiator was not as full as you thought because the air is bleeding out. While the engine is still running slowly add coolant to the radiator till it's full and top off the reservoir and reinstall the radiator cap. The should solve your problem if it was an air pocket. Now if the coolant went low due to a crack in the radiator you should be able to find the leak. Maybe the coolant wasn't checked in a really long time. Good luck. Please repost the results.

If you did have a trapped air pocket you would have the exact symptoms. Is it possible that the coolant wasn't checked for an extremely long amount of time? When the coolant level runs extremely low and you add fluid when the engine is not running you will most likely create an air pocket. The pocket will not allow the fans to turn on. When the engine is completely cold take the radiator cap off and start the engine. Then slowly add coolant till the radiator is full then top off the resevior, and reinstall the cap. That should fix the fan issue if it really was an air pocket. Make sure you start checking for leaks now.if the radiator is leaking you should be able to find coolant leaking or maybe it was just refilled wrong previously. I had the same probablem after a new radiator install. Good luck and please repost.

if there is air trapped in the system the fans won't work either. Sounds strange but I know this from experience.

I wish I would have seen this post earlier. What probably happened was is that you left air trapped in the system. When the car is col remove the radiator cap and start the car. Let the air bleed out and and slowly fill the radiator with colant till it's full. That should most likely help you. Good luck

The advice about the power flush could be accurate -- if you trust your Lexus service advisor then I'd say follow his advice. Here's the thing with transmissions: they are easy to ignore until you have problems, like the problem you are having now. So generally speaking they are ignored for thousands of miles, foresaking fluid and filter changes until they start to act funny. I'd say that a "regular" transmission service that includes replacing the filter and draining/refilling the fluid could get you back to proper operation. Let your trusted mechanic do this, and if it doesn't work then look into having either Lexus or a transmission shop give you a diagnosis along with a quote for repairs. Here's a word of caution regarding transmission shops. In 30 years of messing around with every kind of car imaginable I have never found a truly honest tranny shop. Their solution always seems to rebuild your transmission or to swap your existing transmission out for a rebuilt unit. Be careful. From what I thought a flush and a power flush were different. Mine was flushed and it worked for me

Very well said Killer. SRK The one thing that wasn't commented on is braking. In extreme breaking the speed rating and quality of tire will matter. With the quality and construction of the Michelin tire I'm pretty sure you will be just as happy as the other post, but in extreme conditions it will be different than OE. And to comment on the vibration check the balance. Bushings, and LOWER BALL JOINT. That freakin balljoint is notorious for breaking.Oh and thanks for the Costco plug Good luck, Costco Tire Center Manager

If you do have experience the rears are super easy. There are pins and clips holding the pads in place. No real tools needed once the wheel is off. I have 20" wheels and didn't even take my rims off. Good luck

I had the same problem at about 150000 miles. I took it in and had the transmiision flushed and 20000 miles later it's just fine for the amount of miles I have.

you should check your radiator fluid level. I had a similar prolem a while back.