SirSam

This should help: http://www.lexls.com/tutorials/body/fdoorpanel.html The hardest is actually the regulator itself. Haven't find a tutorial on that one yet.

Update: I took it to a local mechanic to see what he had to say so i could narrow it down, it turns out he replaced the thermostat & said that he had to bleed the air out which is what was causing it to overheat. This is were i am confused, because I have taken off the inlet housing before when I replaced my alternator & power steering pump & it has never overheated on me before or after that. Are there any mechanics on these forums that can explain or verify this for me, & if so how do you bleed the air out of the system. Thanks.

Are you referring to the Throttle Control Actuator or Throttle Position Sensor? I've never heard of these going bad myself. Throttle Position Sensor: $130 at local store Throttle Control Actuator: $822 at local auto store

That's the one for the ECM - I need the one for the temp gage. But I found it! Believe it or not I found a guy at Autozone who actually knew something about cars and he was able to use their componet locator. Its actually right next to the other one but has only a 1 wire connector. Thanks for the help though! By the way is that whole manual available on this site? or for sale somewhere? Edit 2: "LScott400", can you tell me if you updated the PDF from the ECM to the ECT? Because the PDF you provided is for the ECT (Temp Gauge) & if its correct I'm not quite sure why "oldls400" said you posted the ECM one, because now my posts below are irrelevant. The temp gauge sensor you found is it to the left of the ECM sensor if you are facing the engine block from the front of the car? It looks like I have to remove the air intake system in order to get that out in my SC400. That ECM PDF is very helpful, do you have one for the temp gauge? My dash gauge says its overheating, but there are no signs of leaks or coolant needed so I want to start with the sensor to see if it fixes the problem, thanks. EDIT: After looking at diagram again & engine, it looks like Temp sensor is to the right of the ECM sensor & I can remove the Temp sensor without having to remove the air intake connector because its not in the way. Can anyone verify this for me?

Ok relooked it over, I'm having the same problem except there are no leaks & I never have had to add any coolant its always topped off. I've replaced thermostat & even ran without it to rule it out & it still overheats. I'm completely stumped & am trying to figure out what to do next. I've even taken off timing belt covers ran engine & looked down inside at water pump to look for leaks & nothing at all. Havn't noticed any power loss, but am still going to run compression test for cracked head gasket, if that comes back negative i'm lost lol.

First lets make sure that your heat isn't working. Make sure your car is warmed up then turn heat on high & let it run for a few seconds. If you feel heat it's possible you may just need more freon.

Just to make sure, if anyone knows the answer to this. I should be able to use this same tutorial on my SC400 right? http://www.lexls.com/tutorials/engine/timingbelt.html Is there one that does just the water pump, just wondering if I have to really take the timing belt off to get to the water pump?

Ok, i have read every post in this thread along with these: http://us.lexusownersclub.com/forums/index...p;hl=thermostat http://us.lexusownersclub.com/forums/index...p;hl=thermostat I just replaced my thermostat today because my 92 SC400 would occasionally over heat & fluctuate just under the 3/4 mark for a while now, & today I had to ride with heat on High full blast just to keep the car from overheating. Yes i purchased gasket & installed it with it. Is there some kind of flush that is required & any links or manuals on how to? I drained about a quart of fluid so that when i took of the inlet housing i wouldn't get fluid everywhere. After letting the car run for about 10 mins reservoir was still full & car began to run hot. Took it for a drive & its even worse, having heat on works slower if at all than before. I don't want to just say its the water pump & then that wasn't really it. I don't really have the money to throw into the car to start researching what it might be. I don't mind taking it to the toyota dealership & getting it analyzed for $100 but even then sometimes its not what the professional thinks. If anyone has had the same problem & has had the fix please let me know, because this could even be multiple possibilities in some cases that i have read. I'm gonna start with the simpler cheaper fixes & work my way up. Thanks to anyone who can give me help.

I would like to resurrect this thread since there are unanswered questions that someone could possibly answer. After reading back on this post I noticed I previously replied where the high & low ports are located, Low(On compressor)High(valve above radiator) refill on low side & drain on high side. If I am incorrect please let me know. I had my system last year refilled with R12 & it is again already out of freon, cost me $189 at shop, 2x bottles @ $62per. I had dye added to check for leaks, none were detected at the time, I am going to convert to R134 because its ridiculous to keep paying that for a recharge when I can easily do it myself much cheaper. This time I may have a shop discharge whatever bit of R12 is left over before I add the R134 unless anyone has any suggestions for a discharge kit that is sold seperately? thx for any help provided.

Also, if you havn't done it already which you probably have. You should be able to remove the Radiator reservoir out of the way without disconnecting any hoses to it, it'll make reaching the bolts much easier. :)

Hey everyone, I thought I would ask to see if anyone else has had this issue before. I installed a new PS Pump & Alternator 11 months ago, & I look under my hood last month & there is PS ATF fluid all over the underskirt. I cleaned all of the area up, the hoses, fittings, etc. Ran it for another 2 days & took a look at it again to see if i can find a leak anywhere & there was fluid on the underskirt again (a puddle). But the lines were pretty clean/dry. So I was stomped I did a thorough search & on the pump towards the left back of it was a small line of fluid coming out of the pump. Which looks like it is running down on top of the Alternator & splashing on the sidewall onto the underskirt. Now i am 90% certain it is the pump, but is it common for it to have gone bad already? I bought it from Advance Auto Parts & it seemed to be a good pump. If I were to buy a new one are there any recommendations from anyone that will have the quality to last as long as a PS pump should? I need to get this fixed quick before it ruins my Alternator again. Thanks for any help anyone can give me.

If you still need help with this, you just need to unscrew the 3 screws at the bottom of the bracket that is holding on the Reservoir, the bracked will come off with it this is ok & should stay attached. Also, the hoses are sometimes tight & you will need something to catch the fluid coming out of the two hoses attached when you disconnect them. Also, don't forget to bleed the air out of the lines by leaving your cap off the reservoir & turning your wheel back & forth over & over all the way with the car off the ground once you put it back together.

I noticed my gauge did that the other day, hasn't done it since. The safest thing & its cheap & easy is to just buy a thermostat & replace it.

Thanks for the replys, I'll look at the solenoid filter screen & see what I find. It has been 5 months its possible it got clogged.

Sam: Clean your P/S Rack Solenoid Screen/filter. Do a search on this forum, you'll find plenty of hits. I did that when I replaced the pump, I got it looking brand new. In order for me to look into that I'm going to have to go through the same whole process as taking the pump off. I am going to look into tie rods, bearings & alignments first to see if maybe something happened there. It almost feels like maybe the steering column bent but seems impossible, because its harder to turn right then it is left. You can only notice it when turning at higher speeds, like on the interstate on a corner for instance.

I just replaced my alternator & PS Pump 1750 miles ago. The other day I had to make a quick sudden left turn & pushed my brakes really hard & instantly it felt like my power steering died. Right now it feels like it is running at 20% its capability, compared to what it was like when the pump went out & I had to drive it home before I replaced it. I took the reservoir cap off and did the whole turn left to right all the way 20 times just like when I installed the new pump to get any air out of the lines, but to no avail. Still feels like its running at 20% capability, I don't see any noticeable leaking as in a line busted & it lost its vacuum. Does anyone have any suggestions?

Whats this have to do with the topic? Here's the thread to the question lol... http://us.lexusownersclub.com/forums/index...showtopic=27434

This will work to... http://www.lexls.com/tutorials/cooling/thermostat.html

I have not done this personally on the SC, but after looking at it. Thermostat should be right in the inlet housing & usually just requires the 2 bolts to be taken off and remove thermostat.

http://us.lexusownersclub.com/forums/index...showtopic=26939

So far it just looks like the Fusible Link, the 7.5a alt sensing fuse, and the 20a radio fuse blew. I'll be replacing the fusible link tonight, it was bolted into the fuse box, very interesting. I'll let you know if I was blessed & thats all I blew. My Alternator was already bad because of PSP leaking. Thats why I was replacing battery so I could drive it home, go figure i bought an inverted terminal battery, well thats a first and to never happen again.(wrong battery that is) It was late & i was tired. Had to special order 150a fusible link from dealer, about $20.

Does anyone know what direct effect it would have on the car if you put the Positive lead car wires on the batteries Negative terminal, and the cars Negative lead on the batteries Positive terminal? What fuses would blow or what devices would be effected? Thanks!

I did some searching but nothing that answered my questions to the entirety. To make it short as possible, battery light came on, cars power started to dissipate, I looked and noticed power steering pump leaking on alternator . So I bought a new battery & installed it so i could drive it home. Now I do NOT get any ignition response, dash lights, power tilt wheel, power seats, power locks, or power windows. However I DO get headlights, brake lights, turn signals, ignition ring light, & door ajar beep. This leads me to believe that the Anti theft System is engaged somehow. I checked all the fuses in the kick panel and engine compartment and they are all FINE, except for the 2 listed below. So my first step would be to get my car started & remedy this problem before I even attempt to replace Power Steering Pump & Alternator. In the engine compartment fuse box I noticed that the ALT 150a & the ALT Sensing 7.5a fuses are blown. My question is, would those fuses blow if the alternator went bad or is that possibly the cause of my alternator not charging because the fues blew & its not the result of the power steering fluid? If I replaced those fuses would they blow again if the alternator was bad? Once I get my car started I will continue onto the next task, but does anyone know how in the would to reset the Anti Theft device? I talked to the dealership and they said to, "cycle the master key in all of the exterior key cylinders in an attempt to reset the anti-theft system." Which I tryed but the key I have when I bought my car looks like a spare, it had no remote alarm built into it and thats all I was given. I tryed several times in different combinations in all the exterior locks but had no response whatsoever. I would love to get my car back in my garage without having to tow her. I can get some pictures up of what im looking at if anyone needs them. Thank you to anyone who can help me with this its much appreciated. Just a quick note also: I don't get any repsonse at all when I turn the ignition to on or all the way, no dash lights, no power wheel tilt, or cigarette lighter, I get no engine repsonse whatsoever. Well only thing it does is beep when i insert the key(door is open/door ajar), thats it.

I get the vibration from 1k rpm's to 1.8k rpm's when accelerating in park or neutral, I assumeed its motor mounts but not sure.

Looks nice, check the interior.