Razor61

Oooooh, I suspect the whole hub assy may need to come off and what’s left of the bearing pressed out then a new wheel bearing pressed in.

Thanks Phil, good question and of course you are correct. This was checked/done by the aircon guy, I watched, helped a bit and learned. I’ve had a think and going back to my electronics days I think I know. We removed the small 12v connector and with the engine running and switching the aircon on, checked the incoming side for 12v as you would normally do with a multi meter and is pretty standard. While I was mauling about removing the compressor side of the connector, pain to remove, so we could get one of the leads/probe into it, I think he must have rearranged the multimeter, switched to measure current and put it in series from the battery positive to the compressor side of the connector ( normally to measure the current) but this will complete the circuit and therefore apply 12v from the battery.

A few weeks ago my aircon stopped working with the AC light flashing. The Air Conditioning isn't an area I know a lot about at all so contacted a mobile Aircon Specialist to have a look. After a few checks it looked like the compressor at fault, either the compressor itself or the magnetic clutch assy. 12v was being applied to the clutch but clutch wasn't engaging so it wasn’t the aircon relay at fault (I presume). So system de gassed and we agreed that I would purchase a new compressor, fit it and then he will re gas the system. I also received some tips/information on what to do while replacing the compressor. New Denso compressor and drier kit purchased from RockAuto Friday afternoon and it arrived the following Monday afternoon, pretty good service. I replaced the compressor on Saturday and I'm waiting for it to be re gassed next week. I thought I'd post some information on how I did it and what bits I needed to remove in order to remove the compressor which may be useful for anyone else that needs to do it or is thinking of doing it. I may have forgot a few details so don't take this as 'gospel' but the basics are there. It took me 4-5 hours to do but I took my time and replaced the drier as well. If I had to do it again it would be 2 hours max. I knew the V belt had to be removed so started with that, removed smallish battery cover, air cleaner inlet and fan with viscous coupling. So it then looked like this. Disconnected the aircon lines to the compressor, placed a rubber glove round each one and wrapped insulation tape round to seal as best I could to stop any moisture entering the system. Used some cable ties to hold the pipes out of the way. Disconnected the aircon electrical connector. Jacked up the car at the passenger side and removed the under tray so I could then get to the compressor from underneath. One quick look told me the compressor has to be removed from the top. I'd already removed the fan assy but I needed to remove the fan cowling as well. 4 x bolts (2 x at the bottom and 2 at the top with captive square nuts) rh one at the top and the 2 x bottom bolts were rusted so plenty of plus gas and left for a while then removed them relatively ok. Had a good look for the 3 x compressor mounting bolts, there are a quite a lot of wires and pipes around this area plus a lot of dirt that will end up on your face and in your eyes while doing the job so wear some glasses or goggles at the very least. Make sure you locate the correct bolts by having a good look at the new compressor as you could easily start undoing the wrong stuff like the oil filter housing/pump. LH bottom bolt is easy to see and remove, LH top is relatively easy but not a lot of room, the RH one at the back isn't easy to see so you need a light to shine round and get to it with a long extension. I removed the plastic engine under cover as well (shown below and be careful of rusted bolts for this as well…………) to give me better access to the RH bolt. Un clipped the fastener for the aircon electrical connector cable which is attached to the compressor. Removed the 3 x bolts, bottom 2 are the same size and the LH top bolt is longer. You will need to work out how to do this yourself with ratchet/extension etc. There are some brackets that are attached with the bolts so take note of these. Wiggled the compressor forward and rested it on the roll bar then removed it carefully from the top between the front of the engine and radiator. Installed the new compressor (see next section about the compressor itself), bolted in place and torqued the bolts to 49nm. Re fitted the aircon line connectors and torqued down the nuts to 10nm after thoroughly cleaning (super clean as best I could), fitting new 'o' rings with a smear of compressor oil, smearing some compressor oil in the compressor connector 'holes'. Reconnected the aircon electrical connector. Installed V belt after cleaning all the pulleys etc. Reinstalled fan cowling, fan assy, smallish battery cover, air cleaner inlet, under trays (basically everything that was removed) and removed jack. Started car and made sure everything still turns correctly. The compressor I received did not have the valve suction plate (the bit with the aircon pipe connectors) but rather a blanking/transit plate, at first I thought I’d bought the wrong one but after reading the instructions it became clear I hadn’t. I needed to remove the suction plate from the old compressor and install it in the new compressor. Make sure the surfaces are super clean, smear some compressor oil on the new seal etc. The new compressor came pre filled with compressor oil but way more than needed probably for transit purposes. You will need to drain out the oil from the old compressor and the new compressor into some separate containers of the same size. Compare the difference and replace the same amount of new oil into the new compressor that came out of the old compressor plus a little bit more. I drained the oil after removing the suction plates and refilled the new compressor after the suction plate was installed. You will need to re fill the new compressor via the hole that ‘sucks’. To find out which one it is, put your thumb on one of the holes and turn the compressor clock wise. You will soon discover which hole ‘sucks’ and which ‘blows’. After refilling with the correct amount of oil turn the compressor over clockwise a few times to distribute the oil inside then fit to the car. There were instructions with the compressor about all this but above is what you basically need to do.

Removed aircon compressor, fitted new compressor, drier and replaced the seals on the aircon line fittings etc. Also put back the stuff I had to take off to get the compressor out in the first place. Under tray, fan shroud and fan assy in order to lift the compressor out from the top.

Yes they are a bit blingy maybe but my opinion, and it’s just my opinion, is that on a dark coloured LS400 they look really really good, stand out and suit the car. I have had lots of comments from people at work saying the gold badges look good.

Not all Lexus dealers charge the earth for LS400 work, Lexus Bolton didn’t when I had a lot of work done in November last year. List of the work I had done is in the link below and it cost £1500. At the time, I asked about the cost for replacing the timing belt and was told they can do it for £400 and £500 for timing belt and water pump which I didn’t think was bad at all that’s why I had Lexus Bolton do it plus the other work. Some dealers like working on the original LS, want to help keep them running/on the road and appreciate the costs can be high so help as much as they can. Judging by the quoted cost in this post, Lexus Bolton definitely helped me! There are quite a few people at Lexus Bolton who were involved with the original launch of the LS400 at Toyota dealerships so they like getting one in to work on and talking about them which is really good.

Absolutely nothing, for a change🤪

It’s been 5 days, 250 miles going to work every day and the idle is still very stable with no erratic behaviour. Car hasn’t cut out when stopping after a decent run on the motorway but the cutting out issue was intermittent so can’t say if that’s been solved yet (my gut/instinct says it has though) What I can say is that I’ve been taking note of the idle speed when stopping after a decent run, or any time I stop for that matter, it’s not the same as before and is very stable and consistent. Definite change in behaviour, when you drive the same car everyday on the same route and roads you tend to notice any change in the way it drives and behaves. I certainly do but I still can’t find the cause of an annoying squeak from the passenger rear😬

£15,000 is definitely out of my price range!

I've been discussing this car with another forum member, it does look amazing and 30k miles.............still like new. The car is close to were I work and was going to go and have a look. I was bidding on it but it went out of my price range, I wasn't surprised though, so won't be looking now.

You’ve done an amazing job and brought the car back from the brink👍

I believe the cost at a Lexus main dealer is £400 for the cambelt and £500 for cambelt and water pump.

Here’s another link that was in the original post I read, this convinced me to change the sensor. https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/377171-diy-coolant-temperature-sensor-change-pics.html

👍 that's good to hear and I'm glad you have done the same thing in the past. My gut instinct was that replacing the sensor has made a difference but after a couple of day's driving I'm pretty much convinced. This post made me think the temp sensor could be the issue: https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/376713-all-ls400-owners-with-bad-gas-mileage-read-this.html

Drove to work this morning, the idle is the same as yesterday and very solid so I took a very short video to illustrate when I arrived at work. I drive 25 miles to work, mostly motorway, and when I leave the motorway a couple of miles from work there are some lights at the top of the slip road. This is the place were I first noticed the engine cutting out when stopped at the lights, I paid particular attention this morning, it was fine and the revs went down to more or less 600 rpm and stayed there. I know that's no guarantee it's been solved at all though. But, previously I have noticed that when I stop at the lights the idle goes low and then most of the time it goes up a bit and engine doesn't stop but it stays lower than it should be. When the engine does stop you can see the revs just die and the engine stops, classic symptoms I imagine. I have done a few other things over the last few weeks, I adjusted the throttle cable and removed the slack a week or so ago when I dismantled the air intake etc to replace the sensor (only to find I didn't have the correct socket to remove the sensor) so put it all back and adjusted the throttle cable. This did improve the cruise control 'smoothness' quite a lot in my opinion. I put some Toyota fuel system cleaner in the tank the last time I filled up which was 2 - 3 weeks ago and the tank is 1/3 full now. The air intake up to the throttle body has been removed a few times along with the 2 x vacuum hoses (one goes to the IACV/idle control valve and the other to the steering pump I think ) and all put back together after cleaning and jubilee clips tightened etc. Maybe that's had an effect but who knows. IMG_0760.MOV

Thanks for all the information, I was aware of the ECU issue and the sensor was ‘working’ so wasn’t open circuit or anything. I replaced it mainly to see if it cured the high/low/erratic idle. I believe that they degrade over time or can do and replacing it can cure the issues I have or had, hopefully. I didn’t disconnect the battery or pull the ecu fuse either, many people recommend that you do. I have another ECU (later issue) and the correct capacitors ready to replace if needed which I will do at some point when I find my soldering iron!

I’ve just replaced the ECU Coolant Temp Sensor on my 96 LS400 as the idle on the car wasn’t right, it could be high around 800/900 rpm - low rpm - round about the correct rpm but wasn’t stable and the common 0 revs sometimes after a decent journey and stopping. It was worse at high revs when you take your foot off the gas and the car keeps driving forward. It started niggling me so I did some searching and came across some info pointing towards the ECU Coolant Temp Sensor that could be the cause. So the sensor was replaced yesterday, I drove to work and back today (50 mile round trip) and the idle seems to be a lot better. The rpm drops to 600 and stays solid at 600 with no movement up or down, yes it is early days yet and it might be just a fluke today but it doesn’t feel like it. The car also feels different but that may be all in my mind and it’s exactly the same, time will tell though I suppose. If it solves the engine cutting out sometimes when coming to a stop I’ll be well pleased.

If I hadn't put the engine cover back on I would have used a pint of lager and see what happened😀 I'm a lager drinker so it would be a more realistic test for me.......I must be getting bored now after doing all the work on the car!! But having said that, I've had to order a new Aircon Compressor as mine has gone 'pete tongue'. It went a couple of weeks ago on the hottest day of the year leaving work, baking hot and the car didn't cool down - checked aircon was on and the light was flashing. First instinct was compressor had gone but did some checks. There is good pressure in the system so no leaks but the compressor wasn't kicking in, checked 12v power to the clutch when aircon engaged- ok there, disconnected clutch assy supply and applied 12v direct to the clutch assy and it didn't kick in. So conclusion is that it's either the clutch assembly or the compressor. It's easier to replace the whole thing, compressor with clutch assy and it should cure it (hopefully). New Denso compressor with clutch assy, AC Drier and expansion valve kit as well should arrive Weds this week from Rockauto in the US. Sounds silly but the USA is the best and cheapest place to get aircon stuff, I did look in the UK but couldn't find anywhere to get the stuff. The stuff was listed but was out of stock. I dread to think what the cost would be from Lexus.

I didn’t just put the wine glass on and rev it🙄...............I did a dummy run holding the glass first, I may be a silly little boy but I’m not stupid🤪

Replaced the ECU Temp Sensor (LS400 1996), took a hour or so taking my time and taking photos. I'll put together a guide and post it when I get chance. When I put everything back (apart from the engine cover) and started the engine to check that the sensor didn't leak, I decided to put a wine glass with filled with some water on top of the inlet manifold and rev the engine a bit just for the hell of it, video is below. Pretty impressive how smooth the whole engine is. Of course I've seen the video, and others, of a stack of wine glasses etc but wanted to try myself😀 TwpeBExmQgSD8txNeovNmQ.MOV

Adjusted the throttle cable on my 95 LS400 and took out the slack as there was too much in my opinion. Left a little bit of slack, throttle pedal is now how I like it - instant throttle response - and checked that the car still idled correctly when warm. Cruise control is better now as well, before it took too much time to react but much better now.

Just to add that the boot looks to be dry now after washing etc, I gave the whole area a good soak with the spray hose and the spare wheel well seemed dry. A bit of water gets in via the aerial to the left hand side but I’m not too bothered about it. I could remove the aerial, for the 4th time, and put a bit of sealant round the gasket but I not doing it all again.

Yep the OEM weather strip isn’t exactly cheap, £100 ish but it’s a doddle to fit without needing to glue the joint. I did find a slight bit of rust on the lip itself but nothing to write home about. If you are thinking about the corners where the water gathers at the bottom of the rear screen, I did find some surface rust last year when I removed the trim and weather strip to clean it all. I cleaned, treated and painted these areas and it’s fine. The 2 x trim outer retaining clips don’t fix in place so I’ve left them as they are for now. The corners are not fixed down with any sealant, I thought it best to leave them as they were for the time being. The trim isn’t going anywhere and at least I know I can lift them up to clean etc.

Replaced the boot seal yesterday with a genuine Lexus one, the boot ‘pops’ open now as shown in the video. Quite a big difference between the old flat tired seal and the new one which isn’t a surprise after 24 years use. It’s done well lasting that long really. D040EBEB-6EA2-4063-B98C-ECE9BEB78B1E.MOV