martin01

I´m am a new owner from Sweden of a Lexus LS 400 -96 which has 25.000 miles on the odo.

I have two problems with my car: (my english isn´n so good but i hope you will understand the problems)

1. I have a heavy vibration at 1200 rpm the first 0-10 minutes when the engine is cold. It feels like the vibration comes from the transmission`or the engine. But I´m not sure. After about 10 minutes you can still feel a very small vibration at that rpm but not as much as when the engine is cold.

2. The car jerks a little bit at speeds over 40 mph. My dealer told me to change the ECU because there have been some problems with these for some LS 400 -96. Does anybody know if this is true?

Lexs400

I've got a similiar situation with the vibration. The reason it is more noticeable at cold temp. versus once the car is hot could be because of the engline oil is still in the bottom of the engine and not reached optimum temp/circulation.
My dealer has been dumbfounded and couldnt figure out the problem.
as for the second issue with the ECU, from what I know it's an expensive part.
Talk to the dealer and ask him that you want them to replace it and test drive it. If indeed that takes care of the problem then you'll pay for it. if they agree to it, fine. if not i suggest you don't waste cash on dealer suggestions. most of the time they don't know what to tell you and just name parts to answer your concerns whether they've proved that or not. that's why if you notice, their answers are always "we've seem this happen... we think.... this might". they never give you a definitive solution . hopefully that will give you the idea.
good luck with it and let us know if you find a solution.

martin01

Thanks!
I wonder if your vibrations has become worse by the time, or is it the same?

Regards
Martin

Lexs400

same.
the guess is that it is most probably related to the MAF (mass air flow) sensors or the vacuum linings going through the front of the engine.
but then again you have to find out if the vibrations occur at that rpm both while driving and idle or is it only at idle ?
if it happens at idle as well then it can't be transmission or differential related since the car is not running. that would leave the engine. it could also be worn out engine mounts. check them first. they're easiest if not cheapest to replace.
however i suggest drive the car like that. if that condition worsens it will be easy to pin point by the dealer and if it doesnt so just drive like that. when you drive the rpm usually stays above 1500 to begin with so my guess is you wont feel much vibraiton during driving speeds.
lexus is funny like that. if you want to keep it perfect it never will, and if you want it to break down all together it never will either. best thing is to just drive it and concentrate on a good CD rather than the vibrations/ squeaks
good luck.

martin01

Thank you for your concern regarding my car-problem

The vibration occurs just at the driving. No vibrations occur when at idle at that rpm. Does your car vibrate when at idle or just at driving?
I´m not so good at the language. What is Engine Mouts? Can you describe more in detail?

Regards
Martin

Lexs400

engine mounts, basically the rubber pieces that are between the engine and the body where the engine is touching the body panels.
they absorb the vibrations of the engine.
in a situaiton like this it might be worth considering the ECU option. but try to talk to the dealer and tell them that you would want to make sure if ECU is the problem and if it is not get their written statement that they will take the part back and give you a full refund.
good luck again.

martin01

I talked to my dealer today. He will replace my ECU for free
Will se if this helps!

I let you know!

Regards
Martin