steve2006

This well known problem. http://www.lexls.com/tutorials/lighting/bulbout.html

So when this problem happens there is no electrical power at all,no dash lights or anything? Do the headlights work? If not I would be looking for a poor battery connection to start with then trace the fault possibly to the main engine relay.

As you say it would appear that the batteries are being charged OK and the alternator is providing a good output,I would look at the damaged connection as it could be high resistance and causing the warning light to illuminate,it may be worth,if you can,removing it and giving it a good clean with some electrical contact cleaner,check all the other wiring to the alternator and make sure all the earth points are good.

I did my TB clean during a starter motor rebuild so took it off completely,it helps if you can get to both sides of the butterfly,you are correct in that you need a new gasket but they only cost a few $$$. I used carb cleaner and an old toothbrush to do the job.

You can read the fault codes yourself for the AC then go from there,the high speed vibration could be a number of things but I would start with a front suspension check for worn components.

This information should be in your driver's handbook but earlier models required 5 litres including the filter change.

Hi, I'm a new 90 LS400 owner and I would like to ask you a little question, but I hope you've got the problem with your car solved by now. My question is: where is the main relay located? I would truly appreciate it if you can answer me... Thanks Hi and welcome,the main engine relay is located within the engine bay fuse box just to the rear of the battery,there are 2 slotted bolts to remove on the top cover and all will be revealed once the lid is off,I think the relays are described on the inside of the cover.

You should get the dealer to do all the work including replacing the other related damage to the spark plug wires free of charge,the parts should have lasted longer than they have,be interesting to know what has caused its early demise.

That's not good were the belt and idlers OEM or aftermarket? At least the engine will still be OK with it being non interference.

Hi and welcome to the LOC, Good you hear you have the car of your dreams. While you have the front suspension stripped check for play in the upper control arm bushes and ball joints, check the bottom ball joints and the anti roll bar bushes. If you want more help have a look at www.lexls.com (tutorials section) most of the stuff is for gen 2 models but yours will be similar regarding the suspension components.

Hi, A very common problem is the driver's side coil pack and although you say it is OK it may be failing when it gets warmed up as they break down internally.For what they cost it may be worth replacing it.

This topic has been covered many times before, This may help. http://us.lexusownersclub.com/forums/index.php?showtopic=15338

Replace the lamps with LEDs these give a much whiter light. Not the best picture but shows the difference and the LED color reflected in the bumper.

Ok. have you checked the wiring to the sensor? I don't know if this would work but if you have a battery drill gently attach the gear of the speed sensor to the drill chuck,turn on the ignition then slowly turn the gear with the drill,get some one to see if the speedometer needle moves.

If the battery is not being charged and the no charge light is on it has to be an alternator problem,there is nothing else that charges the battery,there is a 120A fuse in the engine bay fuse box but when this blows it normally gives a blank dash as well. If you do a little research you will find the alternator is often damaged by leaking power steering fluid from the pump above it and the cure is to replace the reservoir O ring and replace the alternator. BTW disconnecting the battery negative whilst the engine is running may damage the alternator diode pack and regulator. As for the non working speedometer check the 2 speed sensors and the wiring located on the transmission as one of these drives the speedometer.

I had the same problem with my rear caliper whilst servicing the brakes,as you say getting the seized pin out is a real pain. The caliper pins are available from dealers for around $10.00 each,there should also be a rubber bush on the rear upper pins and on both pins on the front calipers,note there are then 2 different types of bushes on the front pins. I have just replaced these bushes on the front calipers in an effort to cure the knocking noise I had when slow cornering with the brakes applied,time will tell if this sorts the problem as up to now all is OK. Note the 2 types of bushes used on the front pins

There are 2 speed sensors on the transmision,the speedometer driven gear will have a drive gear on it.If the one you changed does not this may be the reason why you still have the problem. There are also 4 other speed sensors which are actually the ABS sensors,one on each hub but these are not the cause of your problem

I replaced mine about 12 months ago and it has remained the same color as it was when I put it in,does yours use a different type of fluid? I can't think what is contaminating it as the fluid is not circulated around as such. I would call in at the dealers who did the work and make enquiries there.

Don't you trust us Brits to try and help then Mike? lol :D

Hello and welcome to the LOC. As 1990LS400 says check for the leaking power steering pump reservoir O ring. Aso check out the trunk hinge wiring as this causes mysterious problems,if you check out the tutorials on www.lexls.com it is all explained there (Strange dashboard lighting problems) along with other good information.

The belt is automatically tensioned,the tutorial for replacement is below http://www.lexls.com/tutorials/maintenance/drivebelt.html Once the belt is off spin the tensioner and idler pulleys and listen for any noises or roughness. I did hear one LS400 with the sound you are describing and it was the AC compressor clutch.

I wouldn't try tightening the valve cover bolts as this does not usually stop leaks already present and there was a case once when someone actually cracked a valve cover by doing this. The tutorial is below for replacing the gaskets,it doesn't look too bad depending on your skills. http://www.lexls.com/tutorials/engine/valvecover.html

Have you checked the cam shaft cover gaskets as these can leak and the oil may enter the spark plug holes,if the spark plug electrodes are the correct color (chocolate brown) this would indicate the engine is running fine and the oil is coming from an external source.

If you read the codes for the traction control the chances are it will be this one 19 - TRAC motor ON and OFF operation is higher than a predetermined number of times (accumulator pressure leakage) The accumulator has lost it's pressure.We have a guy in the UK working on rebuilding these with new seals and then repressurising,not sure if there is any one in the US at present This is the device located under a cover at the back of the engine bay. As for the oil warning light,it could be the oil pressure sender unit if the oil level is correct or indeed low oil pressure,the only way to confirm the oil pressure is to hook up a gauge.

You don't say which year LS400 you have but normally on the RHS of the engine there is the AC compressor,does it make the same noise with AC on and off?.Also is the sepentine belt OK?