Cooling System

[K9crew]

moe,

the garage that you went to originally should do the job for FREE if they had any ethics at all ... their misdiagnosis cost you time and money!!

[99lsguy]

MOE,

Do all the things ucf3 has mentioned if Lexus is gonna strip your engine down to replace water pump.

t belt, s belt, idler pulleys, hoses...........

otherwise it's gonna be another 6 -$700 again.

Your car will be like new - good luck!

[bigmalik00]

hello sir, I am in your area and I need help keeping my SC on the road. whenever you have time reach out to me at or at home bigmalik00@yahoo.com thanks

To be honest with you we don't have your car infront of us, hence the reason why we're hesitant to give you a good analysis.  If you live near Washington DC I could take a look at it.  You could take the car to Toyota or Lexus for an analysis.  Sure you'll be paying them close to $100, but they should analysis correctly.  You could also have them fix it.  If the problems isn't fixed, you can always  until they fix it or refund your money.

BTW: Why did you pay $700 for the Coolant Reservoir?  I though you'd change that yourself.  I was hoping were going to pay $700 for the water pump, but not the reservoir.

I would suggest changing the thermostat yourself. It's really easy.

For your V8 Lexus SC400--I would recommend buying some 50/50 antifreeze from Walmart or Pepboys.  I would also recommend a very large bucket, and a good set of Metric tools--no Standards.  Definietely get some decent tools, specifically the ones below. 

I picked up a set from Walmart for $17-18.  Best investment.  Also, you'll definitely need a new Thermostat.  Lexus or Pepboys will have that.  It doesn't hurt to get a good pair of socket wrenches either.

Lift the front end up on stands/jacks-bricks behind the rear tires.  Drop on the floor, and search for the white coloured plug connected at the bottom of the radiator.  Once located, put the bucket underneath and open the plug, and the radiator car.  Let it empty out, completely.

You're likely to remove the plastic covers infront of the hose.  There are two bolts holding the hose connector.  Caution, there is a good chance some antifreeze will come out, so keep a towel nearby.  Once you've removed the screws, move the hose connector out of the way. 

The thermostat is inside the part connected to the ENgine.  A counter-clockwise twist will remove that.  Compare the two Thermostats to eachother.

Reconnect-clockwise, reconnect the hose back, and put the radiator plug back in.  Fill up your radiator with the 50/50 antifreeze, and restart the engine.  If you still have the problem, maybe it's time to have Toyota take a look at it. 

Sorry I can't offer specifics, but like I said before, we don't have your car infront of us.  You could always post something titled Help- with your city and state in the title.  See if there's another lexus enthusiast who can analyze your problem.

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[RyLord]

how does one bleed the cooling system.. is there a screw you need to open up while the engine is running ??? I know on my old Lumina 3.4 it had two screws on the coolant lines going into the intake and it hissed out air until done then spewd out coolant....

I think i have a water pump bad in my 93 SC300.... are you supposed to see any water flow in the radaitor when the engine is running or does it just sit still ? i have cap off while running from cold to warmup (10 mins of engine running) and i dont see the water flow in there... also my heater doesnt work either..... i know its not the flapper inside the ac condeensor area cuz it works sometimes but gets cold fast...

Shawn

Hi first i would like to thank all you guys for taking the time and trying to help me out. The problem was they did not well bled the cooling system to rule out the air pockets, when they changed the coolant reservoir/expansion tank. I did not go to a Lexus dealer cause it was far away from me and my car was over heating big time so i was driving for 2mins and giving it a break 10mins to cool down over and over... and i just pulled up at the nearest garage, i know that a Lexus dealer would never give me this problem, now some guys were asking why did it cost 700$

it was 402 $CND for the coolant reservoir/expansion tank (order form Lexus)

105 $CND for the sensor (order form Lexus)

32$ for Coolant

60$ labour

My coolant reservoir/expansion tank was cracked so it was leaking coolant and the sensor wires on the reservoir was damaged.

they changed my Thermostat for nothing it was there bad so i didn't pay for it.

i just got my car back after 3days at the shop. it toke 2days to order the parts from lexus.

So from now on if i need any parts for my car i m gonna order them from the U.S.

Canadian Lexus dealer are just blood suckers down here and there isn't much sc400s around here in Montreal well not as much as the U.S.

thanks again guys

Moe/Montreal/Canada

[SirSam]

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.

[Air Force Rascal]

hi guys,

i had a lil problem with my car today, it over heats and sometimes it will cool down by it self so i tried adding more coolant but nothing yet i brought it in to a Shop and they want to replace my Water Reserve cause there is a leak in it and they are charging me 700$. Did any of you guys had this problem or if any of you guys knows a place where i can buy this part for a cheaper price the dealer wants 600$ for it .

they tolde me its a coment problem with the SC400 V8 is this true?

Go to car-part.com there are plenty of places there that can help you and reasonable...good luck

[SirSam]

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?

[SirSam]

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.

[SirSam]

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.

[schott1984]

I had a sable that was overheating because of that. What is the proper method to get air out?

[PatrickB]

I had a sable that was overheating because of that. What is the proper method to get air out?

I may be way off on this one, so anyone PLEASE correct me if I'm wrong!

It's been some time since I've worked on a water cooled car, but I would fill the

radiator. Start engine with cap off, and wait for thermostat to open. Then I would slowly run engine rpm up higher and higher

and continually add fluid to the radiator as the higher rpm's would lower the visible amount of fluid level in the radiator.

I would do this until about 1000 rpm's short of redline, then place the radiator cap (sealing the system) before decreasing the rpm's.

Alway's worked for me in the past!