LS4zerozeO

When I come to a complete stop, say at a red light or something, the car jolts like it kicked into gear except it keeps on happening in 1 second intervals. It did that before but not as much and not as often so i did not pay much attention to it. The car has pretty bad hesitation now and shifts are not as smooth as it use to. When the car is idling I could hear the jolts through the exhaust when I stand outside. There is a slight thump sound that comes out when it jolts. PLEASE HELP!! I suspect the problem is the result of a worn timing belt or maybe the transmission. Has anyone had the same problem? BTW When does the tranny usually go out? The problem got worse dramatically last night. I want to have the problem repaired before something extremely serious happens Thank you.

GA400

Do you know the service history of the car? If you are not certain that the only transmission fluid used has been the Toyota T-IV (the book says T-II, but a later tech bulletin says to switch to T-IV which is synthetic), you may have a hodgepodge of different transmission fluids from various service centers. The LS400 transmission is very picky about the transmission fluids and many owners here have had good results by doing a complete flush and refill with the T-IV. Do a search on this and you will turn up many results regarding LS400 and SC400 with similar shifting problems.

Good Luck and keep us posted on what you try and the results you get,

GA400

LS4zerozeO

Thanks GA400 for the reply. I changed my tranny fluid with the TIV fluid from the dealer about 3k miles ago. There was little to no change in the car's performance The complete tranny flush sounds like a good idea though because I only changed the oil with no flush. How would you flush the tranny if you were to do it yourself?

GA400

Here is a link to bananags's diy transmission fluid swap http://lexusmodz.netfirms.com/GS_DIY/completetrans

LS4zerozeO

I wonder if this changes anything but would the problem still be the transmission even if i put it in neutral and the jolts still occur? and also yesterday, i put back the stock intake setup and the problem seemed to be less dramatic.

GA400

Moderators, please move this to the maintenance forum where some expert eyes can take a look at it. I don't want to lead LS4zerozeO the wrong way with my "armchair mechanic" troubleshooting.

Thanks,

GA400

lextek

Sounds like a tuneup is needed. Not trans concerns.

Good Luck.
lextek