alanr

Hi, I've had this problem myself in a 1998 Mk 4 - also when many miles from home. Disconnect the battery and let the electronics sort themselves out with a re-boot. Leave disconnected for 30 minutes before reconnecting. That sorted everything out for me, and I never did discover what the cause was. Hope it works for you. Regards, Alan

Hi, It's easiest to take the headlamps out, but not immediately obvious how to do it . Take the indicator out - 1 x phillips screw on the top of the outer edge of the headlamp, and then lever gently upwards and forwards until the plastic retaining clip is released from the side of the headlamp housing. This will reveal a 10mm stud and nut holding the side of the headlamp housing. 2 x 10mm bolts at the inner edge of the headlamp will leave it free to come out with a bit of a wiggle. Be aware that it is a tight fit in the bodywork - don't use excessive force as the headlamp mountings are plastic and will break if you force them. The housing will only come out and go back in one way - a bit like a chinese puzzle. Whatever you do, use finesse rather than brute force. It took me about 45 minutes to work out how to do it the first time, but headlamp removal is about a 2 minute job (literally) once you have got the first one under your belt. Don't forget that the dipped headlights are HID, and very high voltages are generated from the HID units mounted on the back of the headlamp housing when switched on. Hope this has been useful to you. Regards to all Alan

Hi, As far as I am aware, the second press of the lock button on the key fob will disable the interior motion sensors. The triggering of the alarm after a few minutes is a problem that quite a few Mk 4 owners seem to experience - myself included. In my case, when I first bought the car I used to stick a large bunch of keys in the central cubby hole, underneath which is one of the alarm sensors. I no longer keep any metallic objects in the central stowages, and have not had any more problems. I seem to recall that the sensor mounted there is adjustable, and one of the forum members had his adjusted some time ago - the relevant thread is probably 2 or 3 years old. A search of the alarm posts may throw up the correct thread. I first read about this on the USA forum about 5 years ago so a further search there may prove beneficial. Regards to all Alan

Hi, There is a sensor mounted underneath the centre armrest, and I believe that it is adjustable, but have never tried to find it or adjust it myself. However, it does seem sensitive to metallic objects - in my case a large bunch of keys - and after I stopped storing metallic objects in the cubby holes my random alarm problem went away, never to return. I suspect that some Mk 4s may be more sensitive than others. I seem to recall a thread from a couple of years ago where a Lexus agent adjusted someones sensor for them FOC. Hope this helps Regards Alan

Hi Mike, Hopefully this isn't going to lead you in the wrong direction, but may give you an avenue of thought to consider. As I understand it, you do a high mileage on lpg, using petrol only for the initial engine start each time. Logic dictates that if it runs well on lpg, then ignition is probably not the cause, and petrol may well be. Without discounting the possibility of the in-tank filter being partially blocked, my gut feeling is that this is unlikely. What could be a more likely solution is that if you have been using the same tankful of petrol for several months, then the petrol has gone a bit 'stale' and also that one or more of the injectors are partially blocked, thus giving the symptoms described in your other thread.. If the tank is almost empty, then put some injector cleaner in the tank and top up with fresh petrol. Then give the car a good hard run on petrol - this may well blow the cobwebs out of the petrol system, and give you back a V8 rather than a V6 and two halves. Lpg running does also affect how the plugs operate regarding temperature, and probably also affects overall plug life to a certain extent. How long is it since you last had a plug change? I look forward to hearing how you resolve this problem. Regards, Alan

Hi, Jon Evans wrote a very good tutorial on this subject here - http://evansweb.info/2009/11/15/ls400-centre-console-illumination-repair-part-1 and here - http://evansweb.info/2009/11/22/ls400-centre-console-illumination-repair-part-2 Regards Alan

Hi Miq, I can't comment properly on the phone issue - I have a Nokia installation rather than the original Lexus setup. I believe that the lead in the boot is for the phone antenae. (Mine isn't connected to anything) Some Mk 4s seem to suffer a minor software glitch with the audio when switching the ignition on and starting the engine. My gut feeling is that sometimes the transition from ignition only to ignition/start produces a minor power interrupt to either the satnav head unit or the amplifier under the driver's seat. If this occurs during a critical phase of the audio bootup, then it seems to freeze and requires a push of the CD button to get it going again. Once the button is pushed, the audio remembers where it was before, and all is as it should be. I have a vague memory of reading some years ago that a software upgrade was carried out by dealerships if the customer complained about it. My car doesn't seem to have been upgraded, and over the years I have got used to it and regard it as a very minor embuggeration only. Like yourself I got fed up with the aerial going up and down every time. I nearly always listen to the CD player, and so some years ago I fitted an in-line switch to one of the aerial power supplies. The aerial is driven from the amplifier, and if my memory serves me right then the two power supplies are the grey and black cables at the aerial motor. I only switched one lead, and I cannot for the life of me remember which one. I do recall having to do it on a bit of a trial and error basis, the important bit for me being that the aerial would retract when the ignition was switched off, irrespective of the position of the over-ride switch I fitted in the dashboard. Sorry I can't be more precise, but I didn't take any photos at the time. Hopefully this info may be of some use to you. Regards Alan

Hi, I also run at 30 psi front and back on Dunlop D8Zs. I rarely have more than one passenger, but often have a boot full of stuff. Wear patterns are very good at this pressure - the rear tyres are wearing perfectly flat and even, and have 28k on them now with quite a bit of life left in them. Front tyres have done 10k, and are just starting to show the first signs of feathering on the outer edges. I don't rotate the wheels at service intervals. All my driving is in the UK, so obviously (?) I can't do more than 70 mph. Regards to all Alan

Hi, Whilst on the topic of transmission oil changes, I recently made an interesting discovery, albeit purely by accident. My car (1998 Mk IV) was sat on the drive with the front wheels up on a set of ramps whilst I changed the front exhaust pipe. I took the opportunity of doing the engine oil and filter, and also the transmission oil at the same time. The existing transmission oil had already done 36000 miles without being touched, as at the last B service, the Lexus agent concerned said that the oil was still a lovely pink colour and didn't need changing. When the dipstick was pulled, the oil did indeed look nice and pink, with no smell of burnt clutches, so I have carried on driving blissfully with the same oil. Generally percieved wisdom for these transmissions is that a normal service 'drain and refill' will produce about 2 litres of oil out of the transmission pan, and this proved to be the case when I drained mine. The remaining 80% of the oil stays in the internal pumps and hydraulics, of which a fair proportion probably sits in the torque converter and cooler. Due to appallinging weather conditions, the car then spent the next two days up on ramps without an exhaust or transmission oil. However. when I did get back under the car, some undefined thought process made me wonder if any more transmission oil had drained down into the pan. To my surprise, I then drained a further 3 litres of oil out, making a total of 5 litres altogether that had drained out. Also, the oil that had looked a lovely pink colour on the dipstick, actually looked a very deep purple (not the rock group) when drained into a bowl. 5 litres of bright scarlet Toyota ATF and 1000 miles later, the gearbox feels very slightly smoother than before, although it's difficult to be objective about the change quality, as the only word that really springs to mind is 'imperceptable'. Colour of oil on dipstick is now almost clear, and only has the very slightest tinge of pink - it fact it's not easy to read the dipstick any more. So there we are, an accidental 50% oil change all through having the nose up in the air for 2 days. The oil came from Lexus Swindon, ordered on-line and delivered very promptly. Cost of oil was £32.17 + VAT, and was part no. 08886-82025. Regards to all Alan

Steve, I don't know how much use this is to you, if at all, but on the wiring schematics for a Mk IV there are two earths shown. One is direct from the internal CPU, and the other is from the negative side of all the panel lamps. Both are colour coded black/white. The Mk IV instument panel is not interchangeable with a Mk III, but tends to follow many of the same basic principles and construction. You need to bear in mind that wiring schematics are exactly that - a theoretical circuit layout - and the reality of the wiring often appears to be totally different. In the schematic the instrument panel is devoid of anything downstream of the CPU, which means all gauges and warning captions. I have tried to attach a copy of the relevant schematic, but am not sure how successful I have been. If you want a copy of all the wiring schematics for a Mk IV, then drop me an email and I will forward them to you. Regards, Alan

Hi, That's a long way away to source a couple of exhaust gaskets - I have just bought a pair from Lexuspartsdirect.co.uk (Lexus Swindon) at £ 3.33 each, including postage. They are easy to fit once you get the old bolts out. Mine were so corroded that I had to drill all of them out. Regards Alan

Hi, As it happens, I have just had to replace the front 'Y' section on my Mk IV. I drive a lot over fairly uneven Fen roads, and the underside has been grounded several times, the last time sufficiently to dent the middle box and also scrape the shielding around the pipework in the 'Y' joint itself. I bought a brand new exhaust through Lexus Swindon, and got a good discount as a LOC member. The old exhaust was leaking from within the shielding, and as a matter of curiosity I have stripped that part of the shielding off and found that the inner pipework was very corroded and heavily perforated - it was only the shielding holding it all together. The worst part of the job was having to drill out all the 12 year old bolts and flange nuts at the catalyst joints. I did anticipate problems removing the Lambda sensors, but they both came out easily. Have replaced all nuts and bolts with stainless steel, although I don't envisage ever having to do the job again. Interestingly, my Mk IV has a pair of anti-vibration (tuned mass ?)dampers bolted to each down pipe, which I didn't expect to find. Car is now totally silent again, and Lambda sensors working properly with a leak free exhaust. Tickover is now lower at 500rpm and also slightly more even with the new exhaust. Regards to all Alan

At long last I seem to have managed to work out how to post an image on the forum - or at least I think I have. I seem to be a bit steam powered in this modern world. I can only find one diagram relating to the front bumper, with no dismantling or assembly instructions at all. The diagram is fairly clear, and hopefully this will suffice. Regards, Alan

Do you have the same for removal of front bumper at all? or am I just being greedy? You're not being greedy at all, although finding you the information is not quite as straightforward as it seems. I probably do have the info that you are looking for, but it will be somewhere in a collection of several thousand pdf files that I downloaded from the forum 2 or 3 years ago. My recollection is that the files originated from the USA Toyota Tech Info site, where you can buy a 24 hour membership and download all that you want for any model of Toyota/Lexus. The principle problems are twofold - firstly, I have no index, and none of the files are labelled, unless I have renamed them myself because they were of some interest to me. This means that it is like looking for a needle in the proverbial haystack. Secondly, at the moment I haven't the faintest idea how to include attachments when writing a post on the forum. I suppose I really ought to find out how to do this - it can't exactly be rocket science. At least all this information can then be recycled through the forum. Before anybody asks, all the files refer to a Series 4 only, (1998-2000) and are for cars destined for the USA market. This means that there may be minor differences to UK cars. Also, I know that I don't have a complete set of files - some bits and pieces are missing. However, what I have is available for all forum users. I'm just on my way to Norfolk for a few days, so all this will have to wait until I get back and find a bit of time to look through the files. As Haylands says, you can always buy a CD on ebay if you are desperate. Regards Alan

These panels are also held on with adhesive pads mounted in a vertical plane at the fore and aft edges of the doors, and need to be gently prised away from the door. Somewhere I do have some diagrams and instructions for this procedure. If you send me a pm with your email adress, then I will look the necessary info out and send it to you. Regards Alan

Goldfinger makes a couple of very valid points concerning tyre wear on the front of the LS. The king pin inclination is quite pronounced on full lock on these cars, and this will result in accelerated wear to the outer edge of the tyres. This is not exclusive to Lexus - many cars have pronounced KPI at large angles of lock, and this is a function of the suspension/steering design, and not necessarily a result of poor tracking and alignment. However, an occasional alignment check is invaluable, especially if there is doubt about the car's tyre wear, and if investing in new tyres. I run Dunlop D8Zs all round, now done over 26 thousand, and still some mileage left in them, but not much. There is about 3mm left on both back tyres, and the fronts are approaching the time for change at about 2mm. Like Goldfinger, I have had the front tyres swapped round (inner to outer) about 10 thousand ago. I did contemplate putting front wheels to the rear some time back, just to try and even out the tyre wear, but I never got round to it, and all tyres are still on their original corners on the car. My motoring is a 50/50 mixture of town and motorway, I drive gently in town, but don't hang about on the motorway. I have read these threads regarding tyres, and must admit to being tempted to changing to a different (cheaper?) tyre when the time comes, but have a sneaking suspicion that I might end up sticking with Dunlops - sometimes it's better to stick with the devil you know. BTW, swapping front tyres inner to outer is a non-starter with many modern tyres due to their assymetric tread pattern. Some tyres are also uni-directional. The D8Z is a bit old fashioned in that respect, and can be swapped round. Regards to all Alan

Hi Steve, Wear on the solenoid contacts is a known problem on these starters, and is also common across much of the Toyota range of heavy duty starter motors. I have had this problem with several high mileage Hi-Ace in years gone by, and new contact sets do cure this problem easily and cheaply. However, as the LS starter is very labour intensive to remove/refit, do please make sure of your diagnosis before removal. Double check all other electrical and battery connections before embarking on starter motor removal. I'm not sure which year your LS is, but there's a long thread on the US site with photographs that you will find useful reading. It's for a 98 car, but the principles are the same throughout the model range. If I've managed to work this new-fangled computer technology correctly, then the following link should take you there. http://us.lexusownersclub.com/forums/index...starter%20motor I know that there was a recall on '95 model starter motors, but I can't remember precisely what the fault was. I have a feeling that it was insulation related. The only starter contact part no I am aware of is 28226-72010, which is a Toyota number. This number may not read across into the Lexus parts book and will probably have to come from a Toyota agent. I have a sneaking suspicion that the two sets of contacts may also have separate part nos. There may well be a single Part no for the complete kit of contacts however. Perhaps someone out there has this information. The only gaskets you should need are for the inlet manifold and rear coolant pipes. I don't know any of those Part nos, and suspect that they may well be year dependant. Perceived wisdom is not to split the upper and lower manifolds, but remove and refit in one piece. Check all vacuum pipes for splits - an air leak can play havoc with the tickover on these engines. Allow plenty of time for removing the starter, it's not generally on the normal list of DIY jobs on these cars, but is a straightforward job if tackled slowly and methodically. Do let us know how you get on - all additional information/part nos/photographs are very welcome to add to our knowledge base. Alan

Very impressed with the coin. I just wish that I could keep my vehicles as clean and tidy as everybody else seems to. Regards, Alan

Buying a new car is a very emotive experience, especially when buying a fairly top range model like a Lexus. It is all too easy to let your heart over-rule your mind, and occasionally this can result in the buying experience leaving a sour taste in the mouth. Steve-Bedford will be able to relate to this feeling, to the point where the forum has even started a fund to try and make him feel a little better about the whole sorry issue. (I think he's elected himself entertainments manager) If this is your first experience of owning a Lexus, then above all do not buy the first one that comes along. Look at, and perhaps more importantly, drive several cars before purchasing. Go to the Lexus dealers and test drive a demonstrator. Then test drive their secondhand cars if possible. Compare the feel of a used car to the feel of a new one - they will feel different on the road. Make sure that you can live with soft suspension and light controls - these cars are not for everyone. They certainly handle differently to the big Mercs and BMWs. I liken my LS400 to conning an ocean liner along country lanes and the natural movement seems to be a gentle wallow. On motorways the car comes into its own and drifts serenely and effortlessly along at slightly illegal speeds. I should also say that at steady motorway speeds it tends to defy all known laws of physics by returning over 30mpg. Try as many cars as you can - don't be afraid to walk away from a seemingly nice car. Lexus are big corporate bruisers of a car, and not only are secondhand prices very affordable, but there are far more on the market than the salesmen will admit to. As an owner driver, don't even bother to listen to their speile about the Premium Pack - most of it relates to the back seat passengers. As with all niche motor cars, service history is very important, but not the only criteria. Take time to read as many forum threads as you can on both this and USA forum. Read all the on-line road test reports if you haven't already done so. Do lots of homework before buying, and make sure your head makes the decision, and not your heart. Good hunting to you. Regards, Alan

Hi Steve, Have just read the latest update on your satnav - if my satnav is representative of the system, then it should find a satellite signal long before the 2 mile marker from your home. Mine takes about 20 seconds, even when blocked by tall buildings it always seems to find at least one satellite and display a red GPS logo at minimum. Unless you drive at the speed of light, then 2 miles is far too long. I can't fault your logic process now in thinking that it is antenae related. Although I am a retired engineer, I belong to the old school of external combustion, and a lot of this modern electronic wizardry is quite frankly beyond me, although I do have a slight grasp of general principles. Your satnav has exhausted my meagre knowledge, and I am now reduced to clutching at straws. Your mention of having had a tracker fitted recently makes me pose the question as to whether they share any part of the antenae hardware, and if not, whether they somehow interfere with each other in a radiowave or electromagnetic sense. Is one set of GPS data signals being cancelled out or otherwise degraded by the other ? Do you know a friendly wizard ? The fact that the satnav works on some occasions but not on others actually means that the fault finding process is more difficult. Intermittent faults can be an absolute nightmare to try and resolve in any sensible manner, they sometimes go away of their own accord, but are often found by a sheer random process coupled with a large dollop of luck. I really do feel for you, and have stuck a quid in your fund ! Keep taking the tablets, and above all Nil Desperandum. Regards, Alan

Steve, I've spent the last 36 hours driving around with my eyes glued to the satnav screen - probably at the expense of road safety. So if by chance I have swerved or driven erratically in front of anyone reading this, then I apologise profusely - mea culpa ! It's all been in the interests of science. Firstly, colours of the GPS symbol on the top left of the screen. Mine also has different coloured moods, and I think your assumption that it is linked to how many satellites it can 'see' is a pretty good assumption - it's certainly very logical. Mine has four conditions, the only difference to yours being that my yellow symbol is actually blue. I should point out that I am using a slightly later software version than yours, which may well account for minor detail differences. Mine seems to work as follows - No satellite signal - No GPS logo 1 satellite signal - Red GPS logo 2 satellite signals - Blue GPS logo 3 satellite signals - Green GPS logo (full triangulation) My logo turns blue in built-up areas, and red when first starting up in narrow streets lined with tall buildings. It normally takes about 20 seconds from first starting up to working out who and where it is, but the initial 'where' is often about 100 yards out. That said, it's still a hell of a lot closer than thinking it's in Norfolk. Just as a matter of curiosity, was the location in Norfolk somewhere that you had actually travelled to, or is Norfolk a randomly surreal location travelled to only in the innards of your satnav ? I have also tried driving around with my big thick trusty book of maps wedged in various places on top of the dashboard in an attempt to artificially block the GPS signal, but all to no avail - the GPS logo remained resolutely green. Bear in mind that I live in a very rural location, so green is predominately normal for me. Things to check before spending any money or pouring petrol over the car and striking a match - Drive out to the wide blue unobstructed yonder and see if the GPS logo turns green. If it does, and you are still in Norfolk, then my gut feeling is that the antenae is probably working OK, and that the problem lies in the CD drive somewhere. All the displayed information has to be read from the CD, and possibly the drive is sticking or freezing. If this is the case, then Norfolk is actually a fairly irrelevant place - it could just as easily have been Bournemouth or Carlisle. I should certainly speak harshly to the CD drive, or even chastise it, before taking the dashboard apart in seach of the antenae. With regard to your Xenon headlamp failure, do check for slightly loose or corroded (high resistance) electrical connections at the back of the headlamp unit before splashing out on a new bulb. This type of bulb has a very long life and a very low failure rate, and the symptoms described are typical of a poor electrical connection. Please do keep us all informed of progress - satnav faults are a learning curve for us all. Regards, Alan PS I seem to have somehow inadvertently referred to Norfolk as irrelevant - does this mean I'm now going to get hate mail ?

Hi Steve, I have been reading your threads during the last few weeks and had already taken on board the fact that you were less than happy with your 400. Off the top of my head, I really haven't the faintest idea what colour my GPS icon is, but if you give me 24 hours or so, I will get back to you with some concrete information. No icon means no signal, and I would suspect that the colour changes with day/night panel illumination. You can do a manual calibration - see page 59 of the Nav system owner's manual. I have noted that the signal can be easily blocked by high buildings etc, and also gets confused by repeated direction changes. I do 2 right turns and 2 left turns in quick succession to get onto the main road about 100 yards (sorry, metres) away from my house, and my satnav generally takes about a quarter mile before the cursor aligns with the main road, instead of showing me being 100 yards away in a field. I can't help but feel that your satnav problems may well be connected to all the water that's been sloshing about in your boot for goodness knows how long. The unit is basically a simple CD player, with extra attention paid to protecting it from excessive vibration. It isn't waterproofed, and certainly wasn't designed to operate in a humid atmosphere, and I suspect that that the CD drive may be a better place to start your fault finding investigation. I can probably rustle up an old CD of about 1997 vintage if you want to try another disc before delving too deeply. PM me if you want to try this route. On DHP - I have driven two, and found them both slightly 'crashy' over rough road surfaces. With the standard 16 inch wheels and suspension the ride is about as good as you're likely to get without going to air suspension, although it is like trying to con an ocean liner around country lanes and roundabouts. Also, standard Dunlop D8Zs are still available for about £110. Sorry if that seemed like rubbing salt into wounds. The throttle is a bit of a b*gger, but I can assure you that you do gradually get used to it, although I did have the benefit of coming from a previous car with ECT. (Merc) The thought was endearing, but I really couldn't recommend part exchanging against a traction engine, not only will you end up being divorced, but all your fillings will fall out from the vibration - been there and done it in years gone by. I really do hope that your problems get resolved quickly - I suspect that your car may not have been treated too well in the past, and you are now having to put up with other peoples latent faults. Regards, Alan

Hi Steve, I'd always been under the impression that the satnav aerial was built into the rear screen along with the phone aerial, but having just looked in the handbook, I'm no longer quite so sure. There is a brief note in the handbook stating that objects placed on the dashboard may obstruct the GPS signal, so I can only assume that the aerial is somewhere just under the windscreen area. Perhaps someone with a bit more knowledge can come up with a definitive answer. Do you have a problem with your satnav, or is this just a thirst for knowledge ? I note that worn tyres can affect the accuracy of the satnav - I really must find the time to actually read the handbook properly, and learn to use the satnav for its intended purpose. So far, I've managed to tell it how to take me home, but I already knew how to do that journey anyway. Life seemed to be so much simpler when everything was steam powered. Regards Alan

Mk 4 wipers are adjustable for the parking position, but the wiper arms are slightly different for driver and passenger sides. Start adjustment procedure with wipers in fully parked position. On passenger side, unclip the round plastic cover at the base of the arm, slacken the nut below the cover, and gently ease the complete arm loose from the splined spindle. Do not use excessive force when releasing the arm from its spline. Reposition the arm to where you want it, but leave a slight clearance (1-2mm) between the arm and the plastic rest it sits against when in the parked position. The driver's side wiper works on a pantograph mechanism, and the adjustment for wiper arm height is essentially the same as before, although there is no cover over the spindle nut. You may find this arm will be very tight on the spindle if it hasn't ever been removed from initial manufacture. Once you are happy with the height adjustment, you may find that the pantograph requires adjustment. I did this by switching on the wipers, and then turning off at the ignition switch when they are at full travel. If the blade is parallel with the black windscreen trim at the side, then all well and good. If not, then slacken the two screws at the base of the secondary pantograph arm, and slide on the slotted adjustment until blade is parallel with side of windscreen. Only very minor adjustment is needed here to produce large angle changes. When I bought my car, both wipers parked so low that it was straining the mechanism, and it also left a large unwiped strip at the side of the driver's screen. I had several attempts at adjustment before I was completely happy with the parked position, the area of screen that was wiped, and with no clanking or banging of wiper blades against trim on full travel in really wet conditions. (wiper blades will travel over a slightly larger arc in really heavy rain, or on the high speed position) Like most things in life, the ideal position for me ended up being a slight compromise. Also, wiper adjustment tends to be a very empirical exercise. (a suck it and see basis) I use Bosch wipers myself, 22 inch with aerofoil on the driver's side, 15 inch without on the passenger side. Since purchase, I have been plagued with an occasional squeaky blade with drizzle and light rain conditions. Keeping the blades clean of road film and grease is essential. I understand that the genuine Lexus rubbers are treated somehow to help prevent this sort of squeaking. Use of good quality windscreen washer fluid with an alcohol based inhibitor helps to reduce some of this squeaking. A bootle of vodka would probably do just as well, and it wouldn't freeze in winter ! Hope this has been of use, Regards, Alan

Hi, It enables you to unlock the gear shift from the 'Park' position without having ignition on and foot on brake. Regards, Alan