Rough Idle

[nastylexus]

I've only had my 99 LX 470 for several weeks. Love the car so far. I do notice that the idle is a little rough at stop lights. Slight shaking and it idles around 600rpm. I have all the service records dating back to when the car was new and it was only serviced by the dealer and I've been putting in premium gas. Anything I should worry about?

[denslexusgx470]

First of all, Welcome and Congrats on the Lex! Now how many miles do you have on the vehicle? Sounds very unusual but if it's really rough, then it's not normal.

Btw, nice member # (27,777)

[nastylexus]

First of all, Welcome and Congrats on the Lex! Now how many miles do you have on the vehicle? Sounds very unusual but if it's really rough, then it's not normal.

Btw, nice member # (27,777)

It has about 95K miles and I can feel a slight vibration. The reason I asked was that I used to own an LS400 with more miles and it was silky smooth.

[viclykewhoa]

First of all, Welcome and Congrats on the Lex! Now how many miles do you have on the vehicle? Sounds very unusual but if it's really rough, then it's not normal.

Btw, nice member # (27,777)

It has about 95K miles and I can feel a slight vibration. The reason I asked was that I used to own an LS400 with more miles and it was silky smooth.

the second gen GS series has the same problem that no one else seems to be able to resolve. i've tried seafoaming the throttle body, engine and gas tank to no avail. mine starting doing this at about 85K miles. let us know if you could fix it...

[SKperformance]

It can also be worn engine and tranny mounts.

[cardona6569]

HI: Check the motor and tranny mounts as told in the forum, also, clean the Throtle Body, Idle valve, they tend to rough idle when the AC is not on, a cleaning will help it a lot.

C. PR

I've only had my 99 LX 470 for several weeks. Love the car so far. I do notice that the idle is a little rough at stop lights. Slight shaking and it idles around 600rpm. I have all the service records dating back to when the car was new and it was only serviced by the dealer and I've been putting in premium gas. Anything I should worry about?

[nastylexus]

This was recommended by a member in another forum:

sounds like maybe your TPS is out of sync. If you get a chance disconnect your neg batt terminal for about 5 mins. Then re connect and turn your key to the ON position without starting it. Let it sit for about 2 mins and then turn the ignition on. It should level out and reset itself. Ive had to do that once or twice before in the past.

I tried it and it seems to be a little smoother. Less shaking but you can still hear the engine. I was thinking about some additives like a fuel injector cleaner.

With regards to cleaning throtle body and idle valve, any idea how much the dealer will charge to do this?

[LXPearl]

I use top tier gasoline that has been certified and listed on toptier.com to be certain the gasoline is not the problem.

I use Redline Fuel System treatment (SI-1) available at a number of auto stores such as Advance, AutoZone, and Pep Boys, etc. It cleans the whole fuel system and I have been pleased with its performance in my vehicles. I got started on the Redline because the Toyota dealer gave me the tip about using it on my Previa van.

Sometimes if the LX starts up rather rough, I can turn it off and restart it and everything is smooth again. This happened on my old battery during the past year. It gave out this summer and the rough running on start up has not re-occurred with the new battery.