CptYossarian

I bank transferred a £30 deposit to him, and he removed the advert as a result. I'd assume it's my responsibility for asking questions and/or doing the necessary research before pressing the trigger...therefore I've accepted the loss of the money and told them to put it towards relisting/inconvenience fees. I'll continue searching...with much more vigilance! Or I may just get them redone professionally...

Bother. Nevermind. The seller was open to any questions so it's my fault for not asking the right ones! Thanks for your help, all. Tom

That's what my research told me (I found that same website - it's exceptionally helpful!). I'll be making the three hour round trip to collect them in a week or two so my fingers are firmly crossed.

I've got a 1998 LS400 pictured below, with OEM 16s... My alloys are shot, and I found this decent set of four on eBay for a pretty good price... https://www.ebay.co.uk/itm/Lexus-LS400-alloy-wheels-Very-Good-Condition/143156443730 I've already sent a deposit, so in case the advert goes, here's a photograph of them... However, I'm now worried these are from an earlier Lexus LS400 before they gave them bigger discs/calipers...this has only been brought to my attention by another Lexus-owning friend. As I've committed already to buying and collecting, I'm not going to be that guy and pull out of the deal, but I'd like to know in advance, if possible, if I've stupidly bought some wheels that aren't going to fit over my brakes so I can get them sold as soon as I've collected them. Any help greatly appreciated!

This happened to me, and when a garage had it twice it was 'fixed'. The parking brake mechanism had broken, and it was jamming on making the car shake violently and producing heat too. My dad drove it and it didn't happen, but he must have given the parking brake lever some welly or got it to disengage. Unfortunately he applied it again when he parked up so when I got in and drove it the problem appeared again, as if by magic. It confounded us for a while, and cost me £200 in the end to have done at my local friendly garage (£40ph labour).

No EML at all today, car is still a little rich and tickover's a tad low, but otherwise running like a dream. Maybe it's time to cover my ears, go "LALALA" and pretend everything is fine. :)

Yes, that's very true - it's amazingly simple to work on for a big V8 and the over-engineering of some parts is wonderful (and they remain simple to remove/work on!). Okay, so removing the fuse has the desired effect. Somebody on another forum has suggested pulling the fuse overnight, reinserting it the next day, doing the paperclip test and reading the codes, seeing what it says, and taking it for a drive and then reading the codes again afterwards. This will test whether the codes are actually being cleared by the ECU reset or not. It'll also perhaps reset the car to 0 as it's been messed about a bit by us, with new parts being put on, accidental air-leaks messing things up further...it must not know whether its coming or going :D. This might be the final thing we do so that we can approach the Toyota/Lexus indy with a clear explanation of what's happened and what we need to happen going forwards.

Forgot to add, is there a difference between resetting the ECU by pulling a fuse and resetting it by disconnecting the battery?

Thank you for your responses. Hi, yes, we have replaced the entire part, and there are now no air leaks. The car drives absolutely perfectly (no juddering or sudden/brief losses of power). Regarding the coolant temperature sensor, I bought this: http://www.eurocarparts.com/ecp/c/Lexus_LS+400_4.0_1995/p/car-parts/engine-parts/fuel-and-engine-management/engine-management-sensor/?224660231&1&249771e521a68568d003667d41cabcb0c8a454a6&000572 This was what came up when I put in my car's registration (it might even show when you click the link), so I bought it. Unfortunately I may have committed a mistake - the logic we used was simply that it was cheap enough to buy and seemed easy enough to replace to not bother checking to see if the other one was faulty or not. Essentially, even if it wasn't, the new one wouldn't do any harm! Maybe I'm now living to regret that slap-dashery. The ECU ripple test looks interesting although unfortunately most of that entire post goes way over my head. I'll have to run it past my dad who is much more techy minded as he might understand what we're actually looking for by conducting that test. The very original problem was a high cold idle of around 1900rpm...first it was suspected to be clogged throttle body, but as an ECU reset (via the fuse) changed the idle to 1,250rpm for a couple of days I was advised that it was more likely to be the coolant temperature sensor that was faulty (hence the delay in the car going back to its old ways as the ECU realises that a sensor was throwing a strange reading). The air leak problem was simply caused by a bit of heavy handedness with old brittle plastic and has been rectified. The EML has only come on since we replaced the coolant temperature sensor - possibly because we ran the car with an air leak which might have caused all manner of strange readings to be sent the ECU's way which might in turn have made it instruct the car to do all sorts of daft things. It's hard to say - as you hint at diplomatically, our approach as non-mechanics has been a bit illogical and might have ended up placing us in a position where it's hard to now work out which direction to go in. For clarification, I did a 10 mile drive from cold and it was absolutely fine. I stopped the car, turned it off, then turned it on again, and only THEN did the EML appear. To compound this, what perplexed me even more was the EML appearing when I started the car later in the evening to drive home, but then going off enroute!! As you've all mentioned, this type of problem can indeed cause havoc! But nevermind, it's a £900 car, bought after a Saab began making "ouch my DMF" noises, so I'm calling this one a learning-curve. My dad and I have briefly skimmed over the tutorials on the Internet relating to testing/replacing O2 sensors and it goes a little beyond what we are happy to attempt on the driveway. I think it might be time for us to hold our hands up, write a "report" and then pass it over to a tame Toyota/Lexus independant! At least the car can be driven again - sure I might get 10mpg but it's worth it to hear the quad-stainless-steel exhausts warble. :)

Now fixed :). So we do the paperclip method of shorting the correct pins in socket under the driver's knee as outlined here. Nothing. No codes! Hmm. Weird. Sowe go for a 15 minute drive, on a circular route that covers all sorts of roads. The car starts up and idles at 1,250rpm, but this is normal after an ECU reset. It behaves like a Lexus on the drive. Smooth, effortless, sounds great. Tickover was a bit on the lowside...500rpm, and it dipped below 500rpm twice while stationary. Hmmm, not quite right. Get home, it's now warm. Turn car off. Turn car back on immediately (phwoar - RICH!) and BINGO! There's the EML light. So we do the paperclip test again, and BINGO AGAIN! We have four error codes: Code 21 - Main O2S & Heater Signal Code 22 - ECT Sensor Signal (this is the part we replaced in the first instance...whut?) Code 27 - Sub O2S Signal Code 28 - Main O2S Okay, so all of these could have a significant impact on how the car runs. Some Internetting reveals that the O2 sensor signals can be thrown out by a leaky exhaust, although there's no noticable blow. What this would do, though, is make the car think "Hmmm, a bit lean...MOAR FUEL", which might explain the fact the car was running super-duper rich when cold, or at high RPMs. This would logically explain why resetting the ECU by pulling the fuse "fixes" the high idling for a couple of days, until the ECU detects issues with the O2 sensors and says "wait a minute, something's wrong!" and then changes the idle speed. It's strange that up to this point I'd not seen the EML light at all, though. I do suspect that the SUPER CHIP that the previous person installed might have something to do with all of this now - at first I thought that the chip wasn't connected to anything or doing anything, but now I'm beginning to feel that it's utterly screwed up the car's brain . Even more strange, the EML light went out on the drive home, and it began ticking over at 650rpm. It smelled very rich still, however. Any ideas?

Eek. Yes I can see that the casing is all inclusive and it is a very easy part to replace. I'll see how much it is on ECP, if at all, unless a breaker's yard is the only likely place to "stock" it.

Following on from my earlier thread here, I bought a coolant temperature sensor for £6.50 from ECP and have used the helpful tutorial linked to in that thread to do the work today with my dad. Both of us are absolutely amateurs and do not register on the DIY mechanic scale-of-aptitude, although my dad is an excellent DIYer in general and can identify bolt-sizes and different clips from 100 paces etc. We spent 12 - 6.30pm on this job, and essentially, during this time we do remove the old sensor and then put the new one back in, and then putting everything back is kind of the reverse of the removal process. It wasn't smooth sailing though. We have to erect a gazebo hastily at around 1.30pm because of really heavy rain which arrived hours earlier than it should have done. Some of the parts we've taken off get a bit damp, one of these parts is a plastic air-intake manifold that probably shouldn't ever get wet because air goes through it and into the engine, which might explain why the car now has further problems. We also accidentally snapped off a brittle hollow plastic tube guides the line on the left in this image onto the slightly thicker line above it. When reassembling we had to use glue to stick this back on, and then hope that it didn't fall off again when reconnecting the line. It didn't, and we used a zip-tie to try and tighten it but it isn't doing much. The discussion about that particular line is here but I don't really understand much, only that it's probably important and might explain why the car has the problems it now does. After putting everything back together, I reset the ECU again so the car could "learn" the new sensor (not sure if this was wise or not), and turned it on. It still idles when cold at 1,900rpm, and then settles down to 600rpm after five minutes. I then test drove it, and discovered that the EML now comes on randomly, and when it does the car usually suffers a severe and brief loss of power. The revs dropped to 200rpm at a set of traffic lights and it flashed on for a few seconds, then it went away until I put it under load and it came on again. The car juddered as if it's losing power or not firing, but only momentarily. Then it was fine one moment and pulled tremendously in 3rd and then a few minutes later it juddered again. The EML doesn't stay on, it comes on and off randomly with no pattern or connection with how I'm driving. It doesn't sound like a misfire but I'm not sure what one sounds like. Drove it back home. Thought...."we've been morons and the air intake manifold got a few teaspoons of liquid in it whilst sitting on the ground without anything covering it except a gazebo (it was exposed to moisture in the air and spray from rain hitting the ground. Decided to leave the car running for 15 minutes to see if it burnt the remaining moisture out the other end. Go into house. Come back out 15 minutes later. Car has died at some point. Try to start car, barely cranks into life, and it's running awfully rich (as in, monoxide poisoning within 2 minutes if you stand within 2 metres of the back of the car). Drive it again, same problem. Put it in cruise control at 30mph for 1.2 miles and it's fine. The only silver lining here at least I've not paid £100 to have a £6 sensor fitted but I might have to pay a lot of money to have a more serious problem sorted, especially if, despite our careful attitude, we've managed to mess up a spark plug lead or something and now it's not firing in sequence.This is highly unlikely, but it doesn't feel like a cheap fix. Also, further research would indicate that the high cold idle could also be caused by a shorted out mass air filter sensor, which is an easily accessible big black box on top of the car, costs £27.99 to buy from eBay and is infinitely easier to fit than the coolant temperature sensor. Any help or assistance would be appreciated.

...Well this is the problem, the garage doesn't have a facility to run a diagnostic check on a Lexus. I have asked them to look into the CATs as the recovery guy was very sure this was the problem. I don't really want to have to take it to a main dealer. There is going to be a point where I have to bite the bullet and do that. I am located in Northampton, is there a recomendation for a reasonably local solution with the diagnostics. I have been told that the Toyota dealer will not touch a Lexus. I have confidence in the local garage it is with now but the lack of a diagnostic check is slightly frustrating. Have you tried Blue Streak Automotive? https://www.yell.com/biz/blue-streak-automotives-northampton-3308635/ Toyota independant who knows a lot about Lexus. He didn't have the correct equipment to hook my 1995 up but he has equipment suitable for later Lexus models. It would be worth ringing him in the first instance to make sure, though. Nice guy. EDIT - made mistake of not realising there were three pages to thread, and it's all been sorted. Please ignore me! *shuffles off*

Terribly sorry for coming across like a complete moron, but is it possible to get to the stage where you can access the sensor, without removing any bits that would prevent the car from turning on and working? That's the only way we're going to be able to do the multimeter test. As far as I can tell they only remove some plastic covers to reveal the sensor so this shouldn't stop the engine from being turned on.

Hmmm, the thread you've linked to indicates that normal idle when warm is actually 650 +/- 50rpm, so 600rpm would be fine. I'll have to double-check the next time it's warmed up fully and idling. It doesn't judder or stall when slowing down or at traffic lights. I've got a guy who's happy to clean the throttle body as long as he knows it's likely to fix the problem I've been having - it's a little beyond what me and my dad are able to do (although I'll show him the excellent procedure above to see if he's happy to give it a guy). I'm not going to deny that the throttle body might be clogged - it did well under 4k per year for 10 years - but because this issue can be temporarily fixed by resetting the ECU, it would suggest it's a sensor issue more than a clogged throttle body, so I think I need to set aside a day where we can first do the multimetre test on the sensor, and then see what that says. If all readings are okay, then it'll be on to the throttle-body. How would one be able to tell if a throttle cable was sticking by looking at it? I know you can manipulate it from under the bonnet, but I'm not sure how you would replicate the situation where it would stick? All of your advice has been very helpful and I appreciate your time! Once this issue is sorted I'll then investigate the heated seats (I have a sneaking suspicious that none of them work - the front two definitely don't)...hopefully this is a blown fuse rather than all of the elements being broken as I know that the former is an easy fix and the latter means I'll have to accept the car has no heated seats! It's nice buying a car for £920 - the engine (once warm) and interior is worth that alone :).

Haven't yet got around to doing the multimeter test, but something interesting happened today. I drive around 9 miles each way to work and back, give or take, and let the car warm up before leaving in the morning. As mentioned, it revs high for a couple of minutes, then spends a couple of minutes at 1,100/1,200rpm and then drops to 500rpm. Even if it didn't rev high I'd be inclined to leave it a minute or two before setting off to be kind to it - big engines + short journeys = coked up. Anyway, I had to leave work and get home quickly today, so I got in the car, and set off before it'd done any warming up. I then had to take a diversion, and this involved two very sharp bursts of acceleration onto a dual carriageway, firstly in one direction up to 60mph and then the other up to 70mph. I felt rather guilty for treating a cold engine like this, and then on the way home something strange happened, which has happened before. Without cruise control being turned on at all - active, rather - every time I lifted the throttle the car would maintain speed anyway, as long as it was flat. It's like the throttle was stuck, or rather the engine revs were not going down - no engine breaking perhaps. I then encountered traffic, and the car refused to drop below 1,100rpm, and thus wanted to creep a little too fast. I tried putting it into neutral when traffic slowed up, and the revs bounced upwards and settled back to 1,100rpm. The car was definitely completed warm by now as I'd driven 6 miles. I then blattered the car onto a final dual carriageway stretch and kept it 3rd until 70mph - at the next set of lights it settled down to 500rpm tickover as per normal. Soooo...could this weird behaviour, where the car seems to coast at a set speed, whatever speed I brake down to and lift off the throttle again, without cruise being activated, be explained by driving off when the engine was stone-cold (and, if the temp sensor was broken, when the car "thought" the engine temp was well below freezing)? Sorry for the long post...I hope someone can offer advice! :)

Sorry - I wasn't entirely clear on that point. The very first thing I did when it was sat SORNed on my parents' drive was to remove the chip. We inspected the wires and connector after removing it and couldn't fathom what it could have been doing, as it didn't appear to be physically connected to anything in any way. Either way, it was removed before I began using it as my daily, and following advice I saw elsewhere on this forum, I reset the ECU by removing the fuse for a few hours. Unfortunately it still hasn't "learnt" to run better, and this morning revved at between 1900 and 2000rpm for the first minute or so before gradually dropping to the standard purr that is 500rpm. There's definitely something up with it. I would have suspected a clogged throttle body if resetting the ECU didn't fix it temporarily (i.e. for a few days).

Oooh. Excellent. Thanks.

My dad has the equipment needed to test this out....we just need to find the CTS (which stands for "Something" Thermal Sensor? You can openly laugh at me if you want). :) Can someone chuck me in the direction of the tutorial/a diagram and I shall try not to bother you again!

Thank you for your responses. I understand that the engine is very cold even at +20 degrees compared to its normal operating temperature...but I also believe that if the sensor misreads the temperature it will potentially run rich at the start. Also, I know there are a few people about who've reported this type of issue...I could understand it running a little high when cold, being a big old engine, possibly 1,200 or 1,300rpm, but 1,800 seems excessive. I haven't mentioned this yet, but it's very relevant - it's done under 4k miles per year for the last 10 years of its life - some MOTs were only 1,200 miles apart - so at first I thought I could reset the ECU and "learn" it a new start-up procedure. I did this using the fuse under the bonnet, and then took it for a good long hard run, and after this the car started up and ticked over at 1,100rpm or so for a few days, before reverting back to its old ways. It also had a daft eBay resistor SUPERCHIP!!!1 on it when I got it which was doing between naff and all - I've ruled that out as having any kind of influence over it.

Very helpful post, steve2006, thank you for that information.

Goodish. I do 18 miles a day to work and back mostly on a dual carriageway and pepper this with some trips into town. Last tank was 20mpg, tank before, which included a nice long run out to Grantham, across to Newark, and back down the M1 around 26mpg. Obviously it's running very rich for the first few minutes when cold. You can see it coming out the exhaust even when it's well over 20 degrees C outside. ambermarine - I can barely identify one end of a spanner from the other, and would rather not tempt fate messing around with sensors, unless' literally as simple as "unclip dud sensor from x compartment, fit new sensor into its place, try car". This chap at the friendly garage doesn't want to do this without any data showing that this is the problem though, which I can understand.

'Evening, My LS400 runs at 1,800rpm for about 3 minutes and gradually drops to the perfect 500rpm, after which it runs like a dream. I've been advised by a very friendly local Toyota indepedent (Blue Streak Automotives - Tweed Road Northampton) that it is likely the temperature sensor that's gone wrong - essentially reading the engine temp as -15 or -30 degrees when it's cold so running the car very rich. He said that if he could diagnose this as the issue I'd be getting everything sorted for around £100. Unfortunately my car is just too old for him to read the live data when starting the car up from cold. Without having to go to a Lexus stealership and pay £99+VAT for an hour's labour just to have the car plugged into the system they have, I was wondering if it was... A - possible to buy a contraption that reads data from a 1995 (M - registered January '95) as the car is started up from cold B - possible that anyone on here knows of a garage well within the Northants area that has access to such technology that won't charge silly money for diagnosing this This problem isn't absolutely critical - it just makes driving the car when cold very difficult, as it wants to creep at 30mph, so slow manoevering is more or less impossible, and I don't want to knacker the gearbox putting it into gear when it's running that high, nor do I want to wear out the disc brakes trying to reign the car in! At present I can warm the car up in the mornings as I have the spare time, but I'd rather not do this, and fixing this issue will make the car mechanically spot on, apart from the 15 year old cambelt of course. Any assistance would be greatly appreciated! :) Thanks, Tom

Colin - is this something a local mechanic would be able to do cheaply? I have a very good local mechanic who avoids all complicated cars with electronic gubbins under the bonnet - I am hoping a 20 year old Lexus, while huge, is more basic and easier to work on than your average 10 year old saloon of a similar size. Malcolm - I think it's a good buy, for £900 or so it's almost "disposable" as long as I can get 6 months or more good motoring out of it. It's worth £900 even without a cambelt change to someone who's an enthusiast, but I'm not thinking about selling it at all. I love it! I know that Lexus cambelts are buried deep and hidden from dirt and muck very well...I'm not so worried about the mileage it's done since the last change in the year 2000 as it's just barely reached the next interval, and a lot of that mileage was done obviously at a low speed and over short distances...it's just the age of the belt itself. 15 years!!! *gulp*

Good evening, I'm dabbling in Lexus ownership mainly to get tick "Own a V8" off my things-to-do-before-I'm-30 bucket list, and at £900 I wasn't going to argue. It was a risky purchase as there's no stamped history between 2005 and 2015, although the MOT history confirms that it only did 37,000 miles in that time, with only 1,500 miles or so between some MOTs. There's no cambelt history either - the only recorded change being done in the year 2000 at 65,000 miles or so, so I'm being proper gambly here, and as I don't want to immediately fork out £hundreds on a £900 car, I'm happy to run the gauntlet of having to break the car for parts if it lunches itself. Anyway, my problem stems from a very high cold idle. It's 1,800rpm for the first couple of minutes, then it gradually sinks until the car is warm (second or third line on the temp gauge?), and then it does the normal Lexus purr of 500-600rpm. I bought it off a dealer who'd been using it for a month or so. They'd naively fitted a SUPER-DUPER EBAY CHIP, which I've removed (it was doing somewhere between naff and all to the engine), and the gan'sta tints that were fitted to the fronts (illegal) and the rears (not illegal but stupid). I first thought it was the eBay chip, so I was disappointed when removing that didn't fix it. However, further research suggest resetting the ECU, which I've done by removing the fuse under the bonnet for a few hours. After putting the fuse back in it ticked over at 1,100rpm when cold - much more normal I thought. I gave it a good 10 mile drive and a bit of a booting to try to make the ECU realise it was going to get more usage now, and for a couple of days it was fine, always starting at 1,100rpm. But it now idles at 1,800rpm again, and as I know have come to realise that it might be an "adaptive" ECU, it might still be thinking that it needs to warm up quickly which is why it's reverting back to this high cold idle speed. A slightly more logical explanation is that the throttle body is utterly coked up because it was being driven short distances for nearly 10 years...this is causing it to idle high because it can barely breath when cold. Not being mechanically minded, am I in the right ball-park? Would a friendly garage be able to cope with replacing a throttle body on a car like the Lexus? It doesn't look horribly electrical and complicated under the bonnet. It's massive but simple in a way. Anyone else got ideas? I know this kind of problem is a pain to diagnose! Other than that it drives like a dream. Just over 140k now, silky smooth engine, quad-tipped stainless steel exhausts for a throaty grumble at low speed, gearbox is perfect and kick-down is effective if not a little uncivilised for a big ol' car like the LS400. Thanks for any help you can provide! :)