crow1

If you dont know how the previous owner used the car or where it came from (mountains wear brakes more than flat land) just take it to your shop or a tire store and ask them to check the pads.

I personally would not use the wear warning light to decide on brake pad replacement.

hello everyone

my names dave and i am a 90'ls owner and heve been puzzled on the operation of my heat.I have played around with climate controls, changed the thermostat.My temp setting is all the way up and when heat is turned on u can hear the chute for the heater core open but after 20 min of driving still no heat.my lcd is blacked out like most ls, im frustrated please anyone help driving in jersey with 20 and 30 degree days is killing me

Try a new radiator (reservoir) cap. Old one may not hold enough pressure. Fixed mine.

I thought about all the above posts. Put a new radiator (reservoir) cap on it and now there is heat. Apparantly not enough pressure to allow water to reach the highest part of the system.

thanks for all the help folks.

thanks. The temperature guage is just below halfway. Is the thermostat still a possibility?

NO

I have checked the control valve and it is functioning properly.

The way this thing just started not heating all of a sudden makes me wonder if there is a sensor bad. The parts lists an in-car temp sensor for the heating system but does not show where it is.

What happens if you put the control in max heat, 85F, and leave it there, do you then get TOO much heat??

Max heat or max cool bypasses the sensors.

And OPEN cabin temperature sensor (little window above the driver's right knee), or even an open OAT sensor (in front of the radiator/condensor behind the bumper) would result in poor or no heating.

Bad thermostat can cause that. In cold weather, engine never reaches corret operating temperature.

I just changed the thermostat. The old one only got between one quarter and one half. Now it is on half steady.

Got heat for awhile when on max heat. Got hotter when running hard above 3K rpm's. I then turned it down to 80 degrees.Then it started only warm at best again. Now even on max heat it is only warm.

Any suggestions? Could it be the radiator cap not holding pressure enough to put water through the heater core?

Anyone know someone who would rebuild the pump? Not sure I want to tackle it myself.

thanks in advance.

Bill in NC

thanks. The temperature guage is just below halfway. Is the thermostat still a possibility?

NO

I have checked the control valve and it is functioning properly.

The way this thing just started not heating all of a sudden makes me wonder if there is a sensor bad. The parts lists an in-car temp sensor for the heating system but does not show where it is.

What happens if you put the control in max heat, 85F, and leave it there, do you then get TOO much heat??

Max heat or max cool bypasses the sensors.

And OPEN cabin temperature sensor (little window above the driver's right knee), or even an open OAT sensor (in front of the radiator/condensor behind the bumper) would result in poor or no heating.

Bad thermostat can cause that. In cold weather, engine never reaches corret operating temperature.

I just changed the thermostat. The old one only got between one quarter and one half. Now it is on half steady.

Got heat for awhile when on max heat. Got hotter when running hard above 3K rpm's. I then turned it down to 80 degrees.Then it started only warm at best again. Now even on max heat it is only warm.

Any suggestions? Could it be the radiator cap not holding pressure enough to put water through the heater core?

I posted this on the other Lexus site and got some good replies, but wanted to try here as well for more info.... I was told it could be mounts, tires, tranny fluid, etc.

My friend is experiencing another potential "problem" with her LS400. Between about 35-55 mph, it has a rumbling type vibration that can be felt slightly through the steering wheel. Ive driven the car... its not bad, but where the car is otherwise so smooth, its bothersome. The sound is not loud, but it seems to "drum" in your ears. Also, not sure if its linked, but when the temps are cold out, and the engine is not fully warmed, when the car is in 4th gear and at a lower speed under light acceleration, there is a slight whistling/humming noise coming from the car. My old 90' LS400 had a similiar vibration and it turned out being the tires, so it may be the same case with this car. OR, I was thinking that vibration may be something like an engine or transmission mount? I am actually having the same problem on my car.... !!

Lastly, on acceleration from a stop, there is a slight hesitation just after the car starts out. It has a new air filter, so I do not think thats it... I am thinking maybe the throttle body needs to be cleaned?

Any advice appreciated!

I hope I provided enough info... if more details needed to help out, please let me know and I will relay more info if I can.

In the 12 years I have owned my 93, the only time I have had the problem you describe is with tires. Until I finally broke down and rebuilt the front end (bushings, etc) when the tires got worn, this would begin until I could not stand it. Bought tires again.

Check the tires first

thanks. The temperature guage is just below halfway. Is the thermostat still a possibility?

I have checked the control valve and it is functioning properly.

The way this thing just started not heating all of a sudden makes me wonder if there is a sensor bad. The parts lists an in-car temp sensor for the heating system but does not show where it is.

Bad thermostat can cause that. In cold weather, engine never reaches corret operating temperature.

thanks. I will check that. If it is the servo motor, does it require taking the entire dash apart?

My 92 LS has a heater coolant flow control valve in the engine compartment near the top center of the firewall. The valve is driven by a cable through the firewall attached internally to the reheat mixing vane/door servomotor. If you move the setpoint from max heat to max cool you should see the valve move about 90 degrees, from fully open to fully closed.

If you detach the cable and it doesn't move full travel then the problem is inside the dash, probably the servomotor.

Hello,

anyone know if a climate control unit can cause a low temperature heat? Until recently the heater would run you out of the car. Now on max hot it is not very warm at all. If so, anyone know of a rebuilder?

If not the climate control, other possibilities?

Unit has never been touched. LCD's are still working.

thanks in advance.

Bill in NC

Folks,

I have read the posts and am trying to decide what to do. I have excessive tire wear. I have rebuilt the front suspension and now I know I nead to build the rear.

For those that have done the work, what have you been happy with, What parts are required, Where did you get the parts?

rubber or poly?

thanks in advance.

thanks very much.

It is a good car that breaks down in the driveway home!!

My wifes car left coolant on the driveway and the garage last night. It is coming from the area under the throttle body. It is hard to see but a steady stream is pouring from the area.

What would be the logical diagnosis? suggestions?

thanks in advance.

I am going to remove and replace the front struts on my ls400. While doing this, are there other parts or recommendations that I should consider?

thanks

Fixed!!!

Actually nothing wrong except the wife had used the key to lock out the remote opener.

Oh well, learn something everyday.

Today the trunk opening switch is not working. Any suggestions would be appreciated since I am leaving on a trip for Thanksgiving. At least the key still opens the trunk though!

The new egr valve and adjusting the TPS after installation and warm up...runs smooth as silk...rpm level at 650...finally fixed

thanks for the help.

you are probably low on Brake fluid......check that first and foremost.......

those sensors in the resevoir are very sensitive, i had that happend b/f and it was only a 1\4 of an inch below and it triggered the light

good luck

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you were right on. Added very little fluid and no more light.

thanks

The parking brake instrument light comes on and off...without the brake being applied. Is there a sensor that needs cleaning or what would be another diagnosis?

thanks in advance.

Hmmmm, it sounds like you're going to have to do a little more trial and error.  I'm a little confused...are you tapping the throttle body?  If you are the TPS is connected to it.  Yours may look slightly different than mine if your LS has TRAC, then it would have two sensors connected to the throttle body.  If tapping this does something the TPS may have been damaged when the throttle body was cleaned.

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No, I am tapping the egr valve. the valve on at least the 94 is different from the site. I took it apart and cleaned it but that did not help. There is a plunger inside that moves up and down. I assume the carbon buildup has made the plunger unable to ride completely inside the egr It still runs fast idle unless tapped on. I have ordered a new one and hope this will take care of the problem.

thanks

Was the throttle body fully cleaned, meaning did you take the thottle body off?

I'm not sure about the EGR valve, my guess is that it's not that.  What I think you need to do is adjust your TPS.  From the tune-up things have changed, especially the thottle body, part of the tune-up is adjusting the idle speed.  This should help ya: http://www.lexls.com/tps.html 

You can try making adjustments on the TPS before buying any new parts.  Let us know if it works out.

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thanks Lexls,

You have a nice site!!!

The photos of the model LS 400 on the site are different than mine. The egr valve on my 94 has no filter. It has two by pass water lines connected to it as well. I took it apart and cleaned it however. There was a great deal of carbon on the plunger.

It did not help the problem. It still idles high until I tap the valve body a few times. And as before, it sometimes idles correctly at start up.

Question: Do you still think it is the TPS that needs adjusting?

thanks again.

My 94 just had a major tune up (plugs, wires, cap, rotor button, throttle body cleaning, etc). Now it has fast idle issue (1100-1200 rpm). Oddly I can tap on the egr valve and it will drop to 650rpm and continue there until car is turned off. Fire it back up and the fast idle will start all over.

It would seem that this would be a sticking idle speed control valve but why would tapping on the egr valve get it to run? Can a defective egr effect idle spped?

question:

do I replace (or can it be cleaned) the egr valve?

Or is it the idle speed control that needs replacing?

both are not cheap parts...hate to buy t he wrong one.

thanks in advanve for any help.

What have you done to fix the hesitation? Mine does exactly the same thing at about 40mph too.

thanks