Ian Lord

Morning Rupert, The sensors I bought were 2nd hand (used) from Old car parts in Warwick, they confirmed the sensors worked and I had to also confirm the year of my LS400 before they would confirm the parts were the correct fit etc. I guess always a bit of a risk with used (old ) parts but the cost was very attractive compaired with new. They were sent same day by UPS and arrived next day which was great. I got my friendly local garage to fit both sensors, as they are a bit difficult to get at (but easy for them on the ramp) took just 1 hour to fit both, it seems that there is also a oval foil gasket on each sensor when the old ones are taken off, and then reused on the replacements. Because these replacements already had the lexus plug fitted to the cables that saved time when fitting. Worth taking a look to check yours are the same as mine, they fit above the CAT on pipe from exhaust manifold to CAT. regards IAN

After changing the oxygen sensors I removed fuse as per lexls website which should clear the fault code and stop the engine warning light coming on. But the light did NOT clear So just did the code check again with the paper clip and I am now getting code 55 No2 knock sensor signal, So I now need to address this issue. Does anyone have any feed back on how to solve this? I read it can often be the cable or connections rather than the knock sensor it's self. I would welcome feedback also where is this located, I think in the "V" between each bank of cylinders below the intake manifold? but which is No2 and is it easy to get at? I look forward to any feedback Regards IAN

Got the new oxygen sensors from Steve's recomended source, but they were the wrong type of fitting as my LS400 is 1990 Note for future reference: The oxygen sensor has a flange with 2 x bolts so returned to supplier who credited my card account same day. I then tried to find the correct type, it seems the 1990-1994 poss upto 1995 models have this type, later models changed to the screw in type. Lexus dealer in Poole wanted £165 each Plus VAT so that would be just short of £400.00 for the pair!!!Argh I eventually found 2 of the correct sensors on ebay (oldcar parts in warwick) from a 1994 model, £27 each so I got the 2. These were fitted and the problem has been solved. (no lumpy tick over and much better aceleration etc) but not quite back to 100% So if you have an older LS400 be sure to get the correct sensor with correct fitting.

Dear Steve, Got the oxygen sensors from your recomended source, but they were the wrong type of fitting as my LS400 is 1990 the oxygen sensor has a flange with 2 x bolts so returned to supplier who credited my card account same day. I then tried to find the correct type, it seems the 1990-1994 poss 1995 have this type later models changed to screw in type. Lexus dealer wanted £165 each Plus VAT so that would be just short of £400.00 for the pair!!!Argh I eventually found 2 of the correct sensors on ebay (oldcar parts in warwick) from 1994 model, £27 each so I got the 2. These were changed and the problem has been solved. (no lumpy tick over and much better aceleration etc) The only outstanding issue is the engine check light, I did the remove fuse stuff as per lexls website which should clear the fault code and stop the light comming on, just did the code check agian and I an now getting code 55 N2 knock sensor, so now need to address this issue. Do you have any feed back on how to solve this, I read it can often be the cable or connections rather than the knock sensor. would welcome your feedback also where is this located, is it easy to get at? Regards Ian

Steve You are a Star Many Thanks, will udate when sensors changed IAN

Thanks Steve for your excellent reply/advice. It was exactly what I needed to know, and should be helpfull to other "Lexus Lovers" Could you expand on the Brand of 02 sensor used as I undertand some will not fit female thread correctly? From what you say the actual physical operation of the sensors are universal and not specific to lexus which I understand requires 4 wire sensors as they are heated.. regards IAN

Thanks IAN

I have just identified (with piece of wire in diagnostic socket fault code 28) that the reason my engine warning light comes on is the oxygen sensor (up stream above cat) on the right bank has failed. Can anyone advise is RIGHT BANK from drivers seat? or from outside with bonnet open? Or maybe its time to replace both? I can see from lexls what needs to be done, but has anyone in UK forum done this? and is there a good UK source for the parts as they seem expensive, and which make is best fit i.e. Bosch etc. Any feed back would be welcome, Many thanks IAN

Thanks Rupert for your words and the link to lexls.com YES the sensor looks the same as mine, but the place its sits on the link photos is different on my 1990 LS400 (maybe its a later model?) the photo on the lexls link seems to have a flat metal section behind the locking nut, but mine does not. Also the cable lenght on the sensor was not long enough to fit the space shown on the lexls photo.. What I need to know is this the engine speed sensor for sure? Where must it be located for the sensor to do its job (what is it reading?) Do these sensors fail? what's the part number (I cannot find on SEWELL web site which is my normal source of info) Regards IAN

Yes it is near (underneath) LEFT (from inside car) Cam belt cover, and above fan belt pulley, you can see Coil to right in photo, Grey top left in photo is top water hose to radiator, and cable sheath at front centre is to Battery.Does this help?

Just had some hunting noises at tick over on my 1990 LS400 so went to investigate, cable connections etc, and fould this hanging loose, looks like a sensor (see attached photo) clearly its not far from where it should normally be as cable is very short (2") also looks like part of the connector block is broken. This is from same harness as cable to ignition coil (the one mounted on the side) Please confirm what it is,and where it should live. There is only ONE cable into the connector block (all secure) and black shiney concaved surface at opposite end which I guess should be touching something. would welcome your feedback oh wise folks of the Lexus owners club. Thanks

As the guy who started this tread I wanted to say thanks to Malcolm in Kent and also to tell you how I solved the problem. New expansion tank cap was good advice (the rubber had split and was looking old) got a new cap and that increased the pressure in the water system result it blew holes in the radiator!!! So searched for a new LS400 rad, found what I wanted online from ADVANCED RADIATORS LTD in Newcastle-upon-Tyne the cost of £61.86 inc VAT and delivery to me I thought was good value. (I ordered Monday received early Weds) you can pay more for 24 hr delivery. I found various forum folks saying changing the rad is easy which it was (40mins to take out) 15 mins to transfer pipe to expansion tank from old rad and also to transfer the temp sensor, all simple stuff. Then 20mins to refit. All now seems well on the engine water side temp guage dead level never moves above this, and no leaks. The long job was flushing out the water in the engine, 2 heat up sessions (with holts rad flush) , 2 draining sessions, and 3 refills, the time consumming part was letting things cool down so not to cause me any danger when draining off The surprising item was where the rad was made!!! Made by a company called DOLPHINheattransfer.com who are based in the United Arab Emirates, their website is massive,and they make rads for just every car I have ever heard of, makes you think what does it really cost to make a Rad? Ian Lord 1990 LS 400 Bournemouth

My 1990 LS400 had a failed thermostat 8 months ago, I replaced this (plus lexus rubber seal) and all was well. Recently had overheat on a 25 mile trip, had to stop every 5 miles to top up water /let it cool down. when home tracked problem to leak at bottom of radiator, added 2 x bottles of radweld and leak fixed, Now I get temp gauge showing normal, but after 5 miles of so VERY hot water comming out of breather hose from expansion tank. Is it possible the Thermostat got cooked and needs replaceing again? or could it be more serious? Oil all looks fine (no water mixing). Or could it be the radiator? Would welcome feedback from any one who has had similar problem regards IAN Bournemouth - UK

Hi gangster pose man!! Sorry to hear you have same drivers seat back problem, and very pleased my post gave you some good news, the seat is very heavy so when taking seat out through the back door, (be sure to place some old towels or carpet on wheeel arch) I did nt and scratched the paintwork!!!!. Before disconnecting the wiring harness (pull apart block under seat) get seat back level (mine was in maximum recline mode) otherwise you will not be able to move it with NO power. I still have the exploded LEXUS drawing with all the DRIVERS SEAT PARTS (its a fax but I should be able to scan and email to you if this will help?) if you want it send me your email address - My email is: i.lord300@btinternet.com Good luck IAN

last year I had a problem with drivers seat back not working I fixed and wanted to share with members =================================================================== DRIVERS SEAT - LS 400 (1990) We call it “the Dream Machine” I wanted to share with members of LOC the answer to a frustrating problem I recently encountered in the hope others can resolve the same problem should it happen on your “dream Machine” While cleaning the roof with another coat of car polish I was standing on the driver’s door sill and inadvertently must have touched recline button on the side of drivers seat leaving the seat in fully reclined position. When trying to return the seatback to normal driving position the seat twisted, and stopped short of normal, because the LEFT side of the seat was not moving. I searched both the UK & US LOC forums and found that others had encountered similar problems; in my case I was NOT able to drive the car. The solution from members was to locate the Aluminium Tube (with black plastic cover) located at the base of seatback this is visible if you look at the junction of seat & seat back near the hinge. How seat recline works: The way the recline feature operates is by an electric Motor on right side of seat as you look at windscreen, from this there is a tapered metal spline, and the aluminium tube is ridged inside the tube and slides over the spline by this method the tube connects in the same way to the LEFT side and drives at the same speed as the RIGHT side. The Problem is: In my case the LEFT side of the aluminium tube had been cleaned of its ridges (rather like a pencil sharpener) so no drive connection possible to LEFT side of seat. The solution many LOC members had suggested was GLUE it with Araldite type of glue and let it cure for 12hours or more, I did this twice with ZERO success… How to Fix: You will need to remove the seat from the car; there are 4 x 14mm bolts, •slide seat forward remove 2 rear bolts, •move seat backwards remove 2 x forward bolts •You will need lift off carpet covered plastic covers, to find bolts •Disconnect wiring harness •Remove seat via rear door •Remove plastic panel on back seat (2 small Phillips screws at bottom of plastic backing) pull sides of plastic cover off clips on seat frame and slide down to release 2 x clips that go under top of seat frame. •Free up leather from base of seat back by removing wire loops from wire frame section that attach leather also remove 6 x steel clips (3 each side) so you can release leather and foam filler away from lower seatback frame. (leave seat cushion leather in place) You can now see the aluminium tube covered in black plastic tube. To release this tube, you need to remove 4 x bolts (2 from each side) of hinge arm that connects to seat back to hinge arms. When removed you will be able to push seat hinges apart just enough to remove the aluminium tube from the steel splines. NEW ALUMINIUM TUBE: My friendly local garage called Lexus spares department at main dealer and they faxed over exploded drawing of Drivers seat, (ref: MN 2071-A) the aluminium tube was identified as Lexus part number is: 72501D My garage called and ordered the part which was available in 3 days at a cost of £11.08 + vat. I inserted new tube, and put everything back together and all works normally. (Interesting to note that the new part is slightly longer than original which ensures tube does not move from side to side, which is my guess why the problem happened in the first place. IMPORTANT: Be sure the seatback is straight (not twisted, be sure both sides of seat are level) when installing the new part, otherwise the seat will twist when electric motor runs, and seat may not return to correct position. IAN LORD Membership number: 10742 Location: Bournemouth

I have a 1990 - 173,000 mile LS 400, (Love it had it 7 years) I have had little need to use the car in recent months. I last used the car 3 weeks ago on a 100 mile trip, 2 days ago I started up in the garage only to find that shortly after start up there was pink fluid loss on to the garage floor, seemed to come from under the front bumper /spoiler.. as nice straight line on floor. Today I had a check and there was no loss of auto tranmission fuid, or break fluid, so it had to be Steering.. I checked the PS fluid level and it was down, also the fluid had gone a watery pink colour rather than the clear red colour it normally is.. My time was limited but there did NOT appear to be any leaks from the PS fluid reservoir, and as there is a large floor pan bolted to the underside of the engine compartment it is not easy to see where its coming from.. I would guess pipe work or steering rack? which could explain VERY small loss of Power Steering fluid, over last few years. I gave the car a short run approx 2 miles, and the power steering still works, but on return to garage there were some strange noises from the power steering unit, I would guess because of low fluid etc. * How can I confirm what the problem is? * Is this common problem to LS400's? Additionally I have recently ecountered lumpy running / miss firing / on some cylinders plus smoke and smell of unburned fuel from exhaust, before this it never missed a beat since I owned the car, and always ran so smooth and quietly. Would really appreciate some feedback from the "wise men" of the Lexus owners club Regards IAN

Thanks Chips 229 I will investigate, and hopefully resolve soon, appreciate rapido reply Ian

Hi I am a new member with 1990 LS400, had it for 3 years and love it mileage now 152,200. recently had new cam belt, pullies, tensioners fitted, and she runs like a dream. Drivers door handle (OUTSIDE) has recently started to stick OPEN, if I give it a gentle nudge it closes, and lock works normally. Has any one encountered similar problem, and how did you fix it? I am concerned interior light may operate if not resoved as lifting handle activates interior light. Would appreciate some help/ideas. regards IAN