domenics Posted April 22, 2006 Share Posted April 22, 2006 I have had my RX400h for about a month now and enjoy it very much. I do have one issue that that I'd like to know if other drivers are experiencing. During acceleration from a stop or very slow speed, there is a distinct clunking noise when the V6 engine starts automatically. It's very noticible and somewhat annoying. It feels like the V6 engine is engaging with the transmision. Is this normal? Thanks very much! Quote Link to comment Share on other sites More sharing options...
Lexus_Jim Posted April 22, 2006 Share Posted April 22, 2006 I have 9000 miles on mine and can hardly ever physically detect when the motor is running. I think that you have a problem and should take it to the dealer for repair. Quote Link to comment Share on other sites More sharing options...
skyfish400h Posted April 24, 2006 Share Posted April 24, 2006 I have 9000 miles on mine and can hardly ever physically detect when the motor is running. I think that you have a problem and should take it to the dealer for repair. Well, now I can feel it when the engine comes on line. There is no audibible "clunk" noise, but you can feel a perceptable thump in the structure of the car when this happens. Usually before you get half way across the limit line into the intersection. Is it this engagement "thump" that you are reporting or is there an audible noise of some kind? Quote Link to comment Share on other sites More sharing options...
domenics Posted May 6, 2006 Author Share Posted May 6, 2006 Thanks for the replies. Most of the time there is the noticible thump as you indicated. The intensity seems to vary quite a bit. I notice it mostly when I am backing out of my garage in the morning. This is when the 'thump' is somewhat audible. I did have one of the specialists at my Lexus dealer test drive it today. He indicated that it is normal. I guess I'll have to live with it and try to get used to it. Quote Link to comment Share on other sites More sharing options...
jerryray Posted May 6, 2006 Share Posted May 6, 2006 It gets better, or and you get used to it. It also helps not to accelerate to hard, that helps too. I have 10,000 and hardly notice it anymore. Thanks for the replies. Most of the time there is the noticible thump as you indicated. The intensity seems to vary quite a bit. I notice it mostly when I am backing out of my garage in the morning. This is when the 'thump' is somewhat audible. I did have one of the specialists at my Lexus dealer test drive it today. He indicated that it is normal. I guess I'll have to live with it and try to get used to it. Quote Link to comment Share on other sites More sharing options...
LexRexBlue Posted May 19, 2006 Share Posted May 19, 2006 I have almost 10,000 miles on mine. The noise seems to lessen as the car breaks in (I want to say around 5000 miles). Also, it seemed more noticeable with premium gas than regular. I have no clue why. Quote Link to comment Share on other sites More sharing options...
raleedy Posted May 19, 2006 Share Posted May 19, 2006 I notice it mostly when I am backing out of my garage in the morning. This is when the 'thump' is somewhat audible. As I (imagine that I) understand how the hybrid system works, reverse is electric only. If the ICE comes on while you are reversing, it is either because the car is cold or because the battery needs charging. In either case, the ICE is not engaged with or driving the wheels, and the 'thump' felt or heard should be relatively small. I notice it in these circumstances and when it happens it seems to me that the disengaged ICE causes a very small 'lurch', probably as it strains against the engine mounts, with no drive-train resistance to damp the torque action of the ICE. Quote Link to comment Share on other sites More sharing options...
speedyg Posted May 19, 2006 Share Posted May 19, 2006 Thanks for the replies. Most of the time there is the noticible thump as you indicated. The intensity seems to vary quite a bit. I notice it mostly when I am backing out of my garage in the morning. This is when the 'thump' is somewhat audible. I did have one of the specialists at my Lexus dealer test drive it today. He indicated that it is normal. I guess I'll have to live with it and try to get used to it. Yes, it's completely normal. I notice the same thing in the morning with my RX400h. When you first turn the car on it's completely silent and motionless, but then when the gas engine turns on to warm up the emissions control equipment you hear and feel it (the so called thump). I would of course prefer that the car remain on electric only but understand the necessity of the engine turning on so the mild thump doesn't bother me at all. Quote Link to comment Share on other sites More sharing options...
Legacy400h Posted May 19, 2006 Share Posted May 19, 2006 I have around 800 miles on my 400h, and I can definitely feel it when the ice kicks in. Also, the engine rumbles a bit at low speed. I've only used premium gas in it. I'm hoping this will improve as the car breaks in. I do, however, occasionally notice the brakes "slipping". Sometimes, while slowing down, the brakes will seem to slip, then grab again. I'm hoping this will improve as the car breaks in, too. Quote Link to comment Share on other sites More sharing options...
katzjamr Posted May 20, 2006 Share Posted May 20, 2006 the 'slipping' somtimes when slowing down is normal as the brakes are changing from regenerative mode to regular braking in some instances. you can push harder or if you have room release the brakes once and you will get smooth action for that stop. this will not go away, it is how the brakes are designed. also as an aside, 'lareedy's' reply to the ice situation when backing up is a perfect description of what is happening. Quote Link to comment Share on other sites More sharing options...
hybridowner Posted May 21, 2006 Share Posted May 21, 2006 I've had my 400H since 9/05 and have the same problem. It started at 10/05, did go to the dealer and they indicated nothing was wrong with it or it did not do it there. It appears to happen when I pull out of the garage or when the vehicle has sat in a parking lot. It is not consistent. The car has been back to the dealer four times. I actually got the noise to happen at the dealer with the 3 techs, service mgr, sales mgr and another service person. They kept the car for 10 days and reset the ISC code and re-learned the procedure. That was done twice and still has not changed. It just got the vehicle back for the four time the other day and it is starting the make the noise again sporadically. I'm in the process of having the dealer request to replace the vehicle. I paid a premium for the car and I feel you should not have the get used or have that noise. Sometimes it can be real bad. Anyone has any othe ideas or suggestions. Car has 8700 miles on it at the moment. The noise sounds like metal against metal knocking and rocks rolling around in the engine. Thanks for the replies. Most of the time there is the noticible thump as you indicated. The intensity seems to vary quite a bit. I notice it mostly when I am backing out of my garage in the morning. This is when the 'thump' is somewhat audible. I did have one of the specialists at my Lexus dealer test drive it today. He indicated that it is normal. I guess I'll have to live with it and try to get used to it. Quote Link to comment Share on other sites More sharing options...
Jim L Posted June 4, 2006 Share Posted June 4, 2006 I had one as a loaner last week. It DOES start the engine in reverse after about 15 ft and you do hear a slight cluck/thud. After all the engine is starting up COLD, it's amazing it isn't a harder thunk This one had about 900 miles on it and I did notice a faint thunk at every stop, this apparantly is normal. I don't know whether it would bother me or not if I actually owned one but I can wait another generation to get these little kinks worked out Quote Link to comment Share on other sites More sharing options...
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