98 Ls 400 Vibrations

[fblonk]

Hello,

I am new to the club, and have been reading some threads, but have not found anything pertaining to my issue.

I have a 98 ls 400 w/ 110K miles and I have 2 vibrations I am tracking down. I recently purchased this car and have all records of services done up to date.

First is an engine vibration around 1800 rpm. If the car is in park (or neutral) and the engine is revved up to 1800 a vibration can be felt. it clears around 2800 rpm. in gear it is also very noticeable. some info:

all services were done at a local lexus dealership, and every required service has been done. I have checked the plugs and they look good, but should be changed in about 10K miles. the car idles perfect, no hesitation or stumble and all looks ok from underneath and above. Could it be the harmonic balancer? this is where I am heading, but would like to know if there is a way to check this component.

The second vibration is the front left tire area.

The car had new tires on it when purchased (9000 miles on goodyears). I was getting a bad vibration around 40 - 55 mph from the front left. I had the tires rot and balanced, and it was slightly better. I then put on new michelins and it still improved a little. I had an alignment done with the new tires. I have jacked the vehicle and did not fine any play in the tire. Rotors and brakes were replaced by lexus of jacksonville within the last 2000 miles. I have noticed from threads that some owners were having problems with lower ball joints. could this be the culprit?

I am looking for some assistance. any help is appreciated.

Thanks!

[SKperformance]

I would try getting a hunter roadforce balance done local to you .

Also look at your fan and make sure the blade don't have any dirt or damage to them.

[jzz30]

if the above fails maybe it could be your motor,and trans mounts. at about 100k is when mine started to vibrate.

as for the wheel vibration you may want to look in to that ball joint

[mehullica]

Sound like worn motor and trans mounts. Front lower strut rod sounds like a problem too.

[W201 sweden]

Welcome to us!

Regarding the front end vibration, du you have the original rims or some aftermarket ones?

If you change the ET (offset) and steering geometry (which happens with some rims), your car can get a LOT

more sensitive to tire balancing, even to the point of getting "impossible" to get right.

I sure can tell from my own experience - the aftermarket wheels (bought by previous owner) makes a difference on my -95 LS.

And SKperformance has a good point; make sure your garage does not

have a problem with their balancing machine - such machines can also be "off"...

best regards,

Alexander from Sweden

[fblonk]

Thank you for the replies!

To answer some questions and add more points to the story:

I have the original rims that lexus supplied, so no custom work has been done.

I have had 2 different rims and 3 different tires on the left front, and when the tire is on the left rear it is fine, so I know the problem is in the suspension and/or bearings. The vehicle was in a minor collision in the front but all looks good (myself and my buddy who owns a mechanic shop specializing in Toyota/Lexus looked and saw no physical damage). The shop that fixed it did decent work.

I have not had time to mess with the vehicle (I own a business) but I will reply back with my finds/solutions.

Thank you again for all the great replies, some of the things mentioned I didn't even think about.

Fblonk

[brandongeorge]

I have a 91 LS-400 with 145,000 and had same problem. by reading this website many people had this problem and sugested motor mounts were bad. I took it to the dealer and sure enough the motor mounts were bad. I had the mechanic save the old ones for me to look at and compare to the new ones. It did solve the problem.

Hello,

I am new to the club, and have been reading some threads, but have not found anything pertaining to my issue.

I have a 98 ls 400 w/ 110K miles and I have 2 vibrations I am tracking down. I recently purchased this car and have all records of services done up to date.

First is an engine vibration around 1800 rpm. If the car is in park (or neutral) and the engine is revved up to 1800 a vibration can be felt. it clears around 2800 rpm. in gear it is also very noticeable. some info:

all services were done at a local lexus dealership, and every required service has been done. I have checked the plugs and they look good, but should be changed in about 10K miles. the car idles perfect, no hesitation or stumble and all looks ok from underneath and above. Could it be the harmonic balancer? this is where I am heading, but would like to know if there is a way to check this component.

The second vibration is the front left tire area.

The car had new tires on it when purchased (9000 miles on goodyears). I was getting a bad vibration around 40 - 55 mph from the front left. I had the tires rot and balanced, and it was slightly better. I then put on new michelins and it still improved a little. I had an alignment done with the new tires. I have jacked the vehicle and did not fine any play in the tire. Rotors and brakes were replaced by lexus of jacksonville within the last 2000 miles. I have noticed from threads that some owners were having problems with lower ball joints. could this be the culprit?

I am looking for some assistance. any help is appreciated.

Thanks!

[fblonk]

Hello,

I have an update:

The transmission mount was in 2 pieces, and replacing it has cured the engine vibration. The motor mounts "look" ok, I probably will replace them in the near future, but for now the engine is smooth when running.

The front end is a different story. We have checked the ball joints on both sides and they are fine. the front end has no play, but I still get a vibration in the steering wheel at 60 + mph. I am going to take the advise of some of you and have a road force balance done. I will reply later with results.

Another question:

I noticed the vacuum valve on the power steering pump is leaking and I am going to replace it. It looks like every other toyota vacuum valve. Is there a toyota number? Is it a crossover part to toyota?

any reply would be appreciated, Thank you

Fblonk

[jakeroux]

I've been experiencing similar problems on my ’92 with 190,000 miles. I tend to think it is not tire/wheel related (at least mine is not anyway) since I’m on my third set of tires since I’ve owned it and have experienced a similar problem with all three sets. Also, with mine you can feel the vibration get worse as you accelerate (greater load on engine) or as you go up an incline at highway speeds with the cruise on (again, creating a greater load on the engine as you maintain speed up an inclining grade). I’ve previously asked an independent mechanic and the dealer to check the engine and tranny mounts and both said they looked fine. Will post an update if I ever get to the bottom of it, but I was really hoping the most recent set of new tires and balancing would solve the problem.

[CUMan]

Another question:

I noticed the vacuum valve on the power steering pump is leaking and I am going to replace it. It looks like every other toyota vacuum valve. Is there a toyota number? Is it a crossover part to toyota?

any reply would be appreciated, Thank you

Fblonk

The air control valve used on the LS 400 power steering system is also used on several Toyota vehicles.

The Lexus part number and the Toyota part number are the same: 17630-16040.

The part is available from www.newlexusparts.com for $77.74. They pay shipping charges.