ambermarine

Hi Fellow Lexuns I spoke in January on the replacement of the coolant temprature sensor on my 1990 LS400 ,that topic was about cold starts. I have just returned from my annual trip to FLO where I purchased a new genuine Toyota(the part is a universal toyota part and fits in most of the lexus and toyota range of engines) part no 89422-20010 $52 sensor and a new set of the correct Denso plugs for around $54 thats half price of the UK for genuine Lexus parts. I have since fitted the plugs and sensor and the difference in the engine responses are significant and very noticable.Firstly the idle speed which was running back in December at around 1200 RPM for up to 15 minutes before dropping to normal tickover of 600 RPM as now dropped to 4 minutes .The engine is a lot smoother probably because it is receiving the correct fuel mixture and the new spark plugs are producing the ultimate spark. It is only when the changes in old equipment are made that the difference is noticed as the wear and tear on equipment is slow and hard to quantify. The changing of these parts took a couple of hours as the covers for the spark plugs have to be removed to get at the engine temp sensor in addition the front coil and the spark plug leads and carrier have to be shunted to one side to get at the temp sensor.I did'nt drain the coolant because if you don't remove the expansion tank cap a vaccum is created and the temp sensor can be removed without a drop of coolant leaking .A deep 19mm socket is required for the sensor and it is only a torque of 15lb to remove and replace. I did'nt disconnect the battery and remove the dome fuse and when everything was reassembled and the engine started the engine warning light came on, when the codes were checked the engine coolant temp sensor showed as open curcuit confirming what I had done .After the dome fuse was removed and replaced normal code was resumed .If you do it this way you close out any anomolies that may have occured before you started the replacement of parts. The engine sensor does not show a code fault if it is working the trouble is that in my case it was not working accurately as I found when I removed it and checked the resistance status at varying tempratures as per the workshop manual, it was way out and after 22 years that is not surprising. I hope now to get better fuel economy better performance and the peace of mind you get with a Lexus when it is cared for.

Hi Interested to read about the theory of the engine coolant temp sensor,I am in the states at the moment waited till now to buy a new genuine toyota sensor( they are half the price) as I have been experiencing long periods of warm up from cold start at 1200 rpm on my 1990 ls mark 1.the engine as been running at those rpms for upto 15 /20 mins before dropping back to 600 normal.I have a workshop manual and the test procedure confirms the sensor is goosed but the ecu as a fail safe measure for that and it sets the temp at 170 so the engine maintains a safe idle speed initially until the temprature as been constant for a longer period than would be required should the sensor be working properly.Up to this failure or even because of it over the last three winters at low tempratures the engine as been starting with the impression the starter would'nt let go, we think this as been because the Engine temprature sensor was not immersed in coolant this in turn sent misleading extremely low air temprature info to the ECU this then set the cold start at the wrong setting and kept forcing start up procedures even after the engine had started, that issue as now dissapeared after we topped up the coolant.When the engine was running and coolant was moving the problem did not occur when starting.The cold start and coolant temp sensor work in tandem through the ECU and there is a link .I will report back when I have fitted the new one .Dont hold your breath that will be in April when I have finished with the Florida 80s, now those are tempratures I like.

Hi Mark Would you want to change the mona lisa or the statue of Liberty you are talking about an icon and if you change it from its original conception it is no longer an icon.

Hi There is a photo tutorial under back door lock fault posted this week .on the removal of the door card,The replacement of the door glass is a complicated procedure and requires removal of parts of the upper part of the door ie slides and other fittings .I would not attempt this job without a workshop manual it could lead to you damaging the door fittings otherwise.

Although my experience is as described and the specs are well within those recommended I am always willing to learn - what do you suggest? Hi I have been using Castrol Magnatec 15-40 in my 1990 LS400 since I bought it 16 years ago I never do more than 6000 between changes and it still runs as quiet as the day it came into my posession.I have done 130k of the 180k on the clock and as far as I can ascertain the previous owner used the same oil. Castrol discontinued the 15-40 oil last year so I have to use the 10-40 .there as been no discernible difference to the performance and it seems to be cheaper per 5 litres.

I beg to differ I have had this car 16 years I tried in my first year of ownership to drive it in snow and the experience so terrified me I have never tried since it was never designed to run around in snow it as no snow mode and three forward gears with overdrive.I suggest the only way you would get suitable driving and steering ability would be to apply snow chains as in NA and Canada but as they are illegal in the UK I'll play safe and leave it in the garage when it snows.Thats another reason she is 22 years old next year. Pretty much any car can drive in the snow so long as it has suitable tyres. The gearing is irrelevant. And snow chains are not illegal in the UK. Try some winter tyres, I think you'll be astounded at the difference in grip. Hi Not illegal I concur but not practical and as I have already said and if you have not driven a ls400 mark1 in snow with or without snow tyres I suggest you let my opinion be just that and stop beating the crap out of everything I say. Happy xmas

Hi welcome to the forum The main thing to look for is rust ;check the cills especially at the rear around the start of the forward part of the wheel arch the area above the back axle around the subframe mountings ,wheel arches especially the rear and the area around the rear door openings were the plastic insert fits . Electronics; check for blacked out lcds on air con display and radio. Check for any needles and backlighting malfunction on the main instrument cluster. Mechanically; check for worn bushes front and rear suspension. Gearbox; should change up and down without issues of any type if not steer clear. Engine; should start and tick over normally ,if not steer clear .There will be minor issues with a 1990 Mark 1 and over time and plenty of visits to this forum they will be solved but anything major that could lead to a mot failure ,it probably is not worth the effort.

Hi My car spends jan to april in the garage because I spend the same period in SW Florida I have another runabout that I use when the roads are bad so the expense of buying applying snow tyres for a possible snow period is prohibitive. I agree with you if I have not tried them I cannot know what the difference is I do know that Florida is a nicer experience than trying to drive in snow.

I beg to differ I have had this car 16 years I tried in my first year of ownership to drive it in snow and the experience so terrified me I have never tried since it was never designed to run around in snow it as no snow mode and three forward gears with overdrive.I suggest the only way you would get suitable driving and steering ability would be to apply snow chains as in NA and Canada but as they are illegal in the UK I'll play safe and leave it in the garage when it snows.Thats another reason she is 22 years old next year.

Hi fellow Lexuns Having recently had my LS400 mark 1 wheels refurbed for the third time the brake dust stains are starting to stick again.The previous methods of removal have all been poor including propriety brake dust removal foams and cleansers .This morning I tried some Sugar Soap and it is very effective. The trick is to apply it neat with a little water, it comes as a granular powder and you do not need a lot, apply to small areas on the lacquer and avoid getting it on the alloy surfaces on the rear of the wheel as it will damage bare aluminium .If you swill the wheel immediatly the residues will be washed away and any small amounts that have got to these surfaces will be neutralized. ,Happy Xmas everybody

I stand corrected and having assumed this theory because a 1990Audi 90 I owned had a switch which disabled the abs and the theory was extended by my belief that abs is useless in snow as it assumes the car is skidding and does not apply the brakes timed to stop the car before you hit the kerb or whatever is in front of you. As for the low gearing I suppose you could keep the car in low gear while driving in snow but that does'nt stop the front end going were it chooses regardless which direction you turn the wheel.

Hi The snow mode as far as I am aware is simply the deactivation of the ABS and is electronically controlled through the main ignition circuit,consequently each time you turn off the ignition you deactivate the deactivation so to speak. There is no snow mode on the Mark 1 Lexus so mine never sees snow my nerves can't stand the experience.

A steering pump leak will not migrate fluid to the steering rack gaitors, I have had the scenario of losing the alternator because the o ring leaked. The seals on each end of the the steering rack Ram are the suspects and the quickest repair is to replace the whole rack and as they don't fail that often a breaker replacement should be ok.

Your insurance company will be rubbing their hands with glee I doubt that they will insure a standard Ls400 with this mod.

If he has the code he can sell the radio which means thats probably what he wants the code for.I broke a clone of my car seven years ago and kept the radio I decoded it before removing it that way I don't have to remember a code for the radio and it can be recoded if it is ever needed.

Hi Nick There are threads on the LexLs and the Lexusus sites on oxygen sensors and the replacement of ,depending on which one as failed, there are two to each side the main and the sub they are not too difficult to replace and there are heaps of suppliers in the states ranging from OEM to aftermarket. The individual sensor can be checked with a volt meter either at the terminals on the sensor plug or on the engine terminal box but you need to follow complex instructions and have the info on readout voltages to determine what is faulty and what is normal.As the code for the Mark I is different to the code for the Mark 4 I can't determine which Sensor as gone on your car but someone on the forum will have a manual for a Mark 4 and should be able to give you that info.

Hi All I have painted a few wheels over the years to an adequate standard The cans of " silver wheel spray " in your local motor factors are too dark and grey you have to find a really bright silver or try a local auto paint specialist who will knock up some cans to your spec - I did this a few years ago and told the guy to make sure the silver was "Bright and speckly " and I duly sprayed a set of DHP wheels and they stood out a mile - nearly needed glasses they were so dazzling Anyhow after a bit of research I tracked down a motor factors near me in Beckenham who do tins of german paint in silver [ will dig a can out for its name ] the paint match to the original lexus silver is pretty good and is nice and bright about £6 a can, although I would recommend you do the whole wheel rather than just blow it in. He also said he sells boxes of these to the refurb guys who come round your house with the heat lamps and they do all manufacturers wheels. Best thing to do is start with your spare wheel and then do one at a time. Anyhow I will find the name and post it on here. Just a quick one on the subject of paint - have used Auto Paint St Helens www.auto-paint.co.uk/carpaint £6.99 + vat for 400ml mixed aerosol give them your paint code or for bumpers lower cladding code and they mix it up to manufactures spec, very nice guys to deal with. Maurice I agree with the need for a "bright" silver, the CarPlan I used was nice and bright with a decent sparkle but it was enhanced by a good quality lacquer. The wheels on my Ls 400 have been done three times twice with just blast and spray but this time they were baked can only judge this baking method over two years and it seems to be holding up considering the amount of salt that was thrown on the roads last year. The previous spray job lasted about ten years before the wheels looked too bad to be on the car . The other problem is that if the wheels corrode badly the refurb guys will complain about the time it takes to rebuild the surface.The joke in this scenario was ;the refurbisher would'nt do the centres as he deduced that if he baked them they would melt and his set up could'nt spray the discs as a one off.I had to source a nissan silver spray can to match his colour and refurb the centres myself be careful not to apply to much laquer when doing this as too much causes the surface to craze as it drys. I had given him a brand new Lexus wheel that had never been on the car to match up the Lexus colour but he would not do that and said they used a universal silver on all the wheels he did and that although it was'nt the Lexus colour was passable. I can understand that but the centre disc issue I find bizzare,anyway I got it sorted eventually and it means I can redo the centres every time they get a bit scabby, every cloud as a silver lining so to speak.

Hi I would check the altenator as the voltage control regulater is incorporated within and it could be faulty and overcharging the battery . It as been reffered to as a fail safe mode but reading the electrics reference in the workshop manual of the Mark 1 I have been unable to find proof of it . The scenario points in that direction in that as soon as a decent amount of power is taken out of the battery the problem dissappears and returns when the battery as charged up again. If that occurs certain curcuit relays could have a shunt mode to save vunerable components.

That's the Spirit I have been restoring a Mk4 Ls400 most of this year and have changed front and rear sub frames and all suspension bars and control arms and have use Copper Ease on all the bolt shafts to prevent seizing in the future Maurice Just a couple of things that we found on renewing the bushes on the mark 1 ls400. The nuts on the bolts through the bushes have serrated edges which means they are gripping the metal The trick is to unfasten the bolt which I know is opposite to what we normally do .I also found that if the bolts would not move put direct heat onto the nut end but only use oxy/act as the heat as to be precise to the nut and this is the only heat method that creates such targeted heat ,ordinary gas will just heat everything up . We did'nt renew the camber side of the arm bushes so we did'nt have to undo them so they maybe are slightly different in their removal as I imagine the nut end as to be removed first being as the bolt is concentric , the heat method should work as on the straight bush bolt.

Hi Kamzil Did the rev counter needle work properly five months ago when you last ran the car,I have some reservations as I have already said about using battery boosters to start the car as they create voltage spikes and some of the electronics especially around the instrument cluster and audio are very prone to being fried.Are there any other electrical faults showing on the instrument cluster such as backlighting and gauges,is the radio working and the A/C.

Kamsil When trying to identify the problem it is always the norm to eliminate the obvious potential faults. You mention a standing period of 5 months and that to me screams dead battery,the car will start on a battery boost but unless there is sufficient power in the battery to run the electrics on the engine and ecu it will not function properly because the power needed to run the engine is being supplied from the alternator and that is trying in turn to charge up the battery. These cars are sophisticated in their engine management and throttle linkage is not the same as on a conventional carburettor. First of all get a decent battery and try that then if that is not the problem the next step is to check the tickover speeds from cold start to normal running temprature. cold start 1200 revs which drops down to 600 on tickover and after a really long run can drop to 500. If non of that happens then you need it looked at.

It sounds like the battery was flat and you are running on the power from the Alternator which is probably running a host of other electrics in the car. Let the car run for a good couple of hours preferably by running to your mother in law 25 miles away and back and do not use any services in the car Radio A/c etc let the battery take a decent charge. The car is not supposed to move until you use the throttle so there is nothing wrong there . Perhaps you are not used to driving Automatic gearbox cars and if not they take a bit of getting used to. I would never use a battery booster on any car that as electronic engine management ,always charge the battery and let the cars electronics decide what is best for the system.

Yes and its your call,but isnt that like saying I,ll put out the fire that is threatening to burn my house down apart from that smoldering bit over there.

Like Malc says, I replaced mine also many years ago got them from Japarts in London Still have the original invoice and they were genuine Lexus parts with Lexus part no's cost me £215 each+vat and in 2003 that was 25% down from Lexus dealer price. I know there are now aftermarket wishbones available there was'nt then so although I was forced to buy oem it as paid off because 70000 miles later they are still good.

What I don't understand is why it concerns you unless you intend to sell yours. The bombed out price of these cars is a golden opportunity to buy a car that with careful selection and care while it is yours will hopefully last you for the rest of your life. I have owned mine 16 years and it is now 21 years old I saw one last week that is a month older than mine in better condition done only 70k and is a super bargain at £1200 .In fact the wife had to talk me out of buying it because its the same colour and I would have had it as my first car and mine as a second because mine as done 180k. Anyone buying a second hand LS400 should treat it as a lifetime car until circumstances dictate otherwise I did 16 years ago and there is still loads of years left in mine. I take on board what members are saying now about the 430/460 and its over technical problems and I agree but Lexus cannot stand still in vehicle evoloution or they would disappear as a marque. Speaking from experience I believe that when Toyota's president told his engineers back in 1983 to build him the best car in the world and six years and a billion dollars later they produced the LS400 that achievement as not been surpassed and that is why I still have mine.