New used LS400 need advice

[Mid Lifer]

A newbie here, just bought a 1991 LS400, 100k miles. Looks like showroom new runs great but a couple of questions. Suspension seems soft, normal or time for struts/shocks? A slight ticking, which my mechanic said ignore and Lexus service said was fuel injectors has gotten a bit louder over the 500 miles I've driven it. Valves, or anything to be concerned about? Temperature rides at midpoint of gauge most of the time but occasionally kicks up to last mark before overheat, then slides back down. Could this be faulty thermostat? After sitting overnight, steering moans just a bit when backing out of parking space, then is OK thereafter. Finally, transmission seems to have slight vibration after shift to third, from 32-36 MPH, not noticeable when accelerating to highwat sped, just when maintaining speed in that range. I know that this is an 11 year old car. Am I just paranoid or should I worry about any of this.

Thanks,

Kyle

[Steve]

Originally posted by Mid Lifer

A newbie here, just bought a 1991 LS400, 100k miles. Looks like showroom new runs great but a couple of questions. Suspension seems soft, normal or time for struts/shocks? A slight ticking, which my mechanic said ignore and Lexus service said was fuel injectors has gotten a bit louder over the 500 miles I've driven it. Valves, or anything to be concerned about? Temperature rides at midpoint of gauge most of the time but occasionally kicks up to last mark before overheat, then slides back down. Could this be faulty thermostat? After sitting overnight, steering moans just a bit when backing out of parking space, then is OK thereafter. Finally, transmission seems to have slight vibration after shift to third, from 32-36 MPH, not noticeable when accelerating to highwat sped, just when maintaining speed in that range. I know that this is an 11 year old car. Am I just paranoid or should I worry about any of this.

Thanks,

Kyle

your suspension should be quite soft.. however a car of that age should have new shocks... fortunatly shocks are not too expensive so they are worth replacing for that smoother ride.

Fuel injectors are noisy too.. mine is the same on a 92. I got paranoid about this too and sometime think i am hearing all kinds of noises!

I would suggest you change the oil on a regular basis though... i left mine a bit oo late and got a knocking sound on start up.. but cleared when i gave the car an oil change. i try and do mine every 6 months or 6000 miles or change it as soon as the oil starts to look dark brown.

I think maybe somewhere your thermostat may need looking at... mine stays at mid point all the time when warm and does not rise very much when i am in traffic... check out your fan too..see if it kicks in

the vibration on your tranny..is it more of a judder or a vibration?

[Mid Lifer]

The transmission is giving me more of a shudder I'd say, from about 32 mph to 38 mph.

[Steve]

that may be due to old age..i have a 92 ES300 which is very similar to the LS and i get a shudder... but sometime depends on how i drive the car... if i drive fast it does not sudder... but when buidling up slowly it shudders a little... instead of the transmission being seamless it does give that little bit in between.

it is annoying :(

One think you might wish to check is the engine mounts.. if these are worn it does tend to make the transmission judder and the engine moves around whilst the gears change

[Mid Lifer]

Thank you, the shudder is much more noticeable when maintaining a speed in the 30's mph, as you said. My temperature problem, which I thought was thermostat, is according to my Lexus service guy, a cracked cap on the coolant bottle. allowing a bubble now and then. He is advising I try Marvel Mystery Oil for the clicking. Any experience with it?

[Steve]

I think Marvel Mystery oil can be placed in the fuel or in the oil.

maybe the marvel mystery oil will stop the clicking of the fuel injectors... however maybe having the injectors cleaned on the next service may help?

I have never used this oil treatment and would like to see what it is like myself... as again old age causes mine to have a slight tap.... but always remeber.. when it is your own car those little noises are always amplified :D

[Mid Lifer]

the ticking has definitely grown louder in the 500 miles I've had it. maybe the previous owner used Marvel Mystery Oil himself. I'll have to ask him. Next service won't be for a while as I've just had the 90k service done as a preventive measure, so the injectors will have to wait unless the MMO can do the job.

[MarkS]

Hi, your temp prob is almost certainly thermostat sticking, when it gets very hot it forces it to get unstuck. Your shudder, it may very well be the beginning of a fault in the gearbox, on light throtle there is less pressure inside, and so the band/clutch is applied more gently, but when it is tired it might give you this shudder. Get it looked at BEFORE it gets worse as at the mo it might well adjust, if it is a band. Or you might be able to increse the presure a tad which might cure it. Excuse me if I am wrong its been some years since I did auto boxes. Tapping noise, are you sure its not the lifters? MarkS

[ROYT]

Did you check fluid condition and level when idling hot?

First job, change trans fluid and  all other oils and filter 

Only use Toyota T4 trans fluid

I have a friend with a 1990 model still runs well

My '94 still runs like new [well nearly new!]

THE ORIGINAL POST WAS 2002, HOW DID MISS THAT!

Hope i'm not loosing it...

 

Edited March 16, 2019 by ROYT
outdated post

[The-Acre]

3 hours ago, ROYT said:

Did you check fluid condition and level when idling hot?

First job, change trans fluid and  all other oils and filter 

Only use Toyota T4 trans fluid

I have a friend with a 1990 model still runs well

My '94 still runs like new [well nearly new!]

THE ORIGINAL POST WAS 2002, HOW DID MISS THAT!

Hope i'm not loosing it...

 

As long as you remember your name and where you live you'll be fine!