I’ve tried searching on this, but my SC’s heater is out. Well, it actually came back on for a few days last week when it got really cold. Is that a clue of what might be wrong with it? If it will work sometimes and not others? It generally doesn’t work.

I filled the reservoir up with coolant, but I don’t see where you can fill the actual radiator if you even can.

If I need that heater control valve does anyone have suggestions on where to purchase that has the best price? Is this something that I can install myself or is it too complicated? I’m a fair shade tree mechanic. I pulled my power steering pump and alternator as per instructions found on this forum. That’s about the extent of my mechanic skills.

 

I have the same question...my heat is ice cold....if I had know this I would have run it during the summer..lol....so if anyone answers your question...please forward to me....thnx..

 

My 94 SC4 just had the same problem. There is a diag test for the VSV which controls the actuator on the water control valve. However there is a simpler test. If you take the vacuum hose from the VSV and plug it directly into the actuator and you now get heat (engine warm, wait a minute or two), then your VSV is bad. See the two photos below. First photo is how the vacuum hoses should be routed. Second photo is the re-routed hose directly to the actuator. A local lexus gave me the following part numbers 88690-24060 ($225) for the VSV and 87240-24040 ($325) for the whole water control valve unit. It's much less at Carson's and I just ordered my VSV today. By the way, if you keep the hoses rerouted, you'll lose cooling efficiency when it gets warm outside but it's a good alternative until the replacement part(s) come in.

 

Here is the re-routed hose picture

 

Well, I ended up having to replace my ‘heater control valve.’ $400 list price for that ****? Are you kidding me? I ended up ordering it from Parts.com for a total of $317. Still, the most outrageously overpriced part that I’ve ever had to purchase. Hands down. It’s hard to believe they can get away with charging that much for it. There’s nothing to it.

It’s really easy to replace. Three bolts and two hose clamps – pull the vacuum line off and then do the reverse to install the new one. No big deal.

Here’s a picture of that part that Lexus is ripping people off on:

 

Yeah dealer prices are a joke! Unles you work there of course ,but still the prices are high. I was going to say go to a junk yard and try your luck with one of those. So replacing that took care of your issue?

 

Thanks alot 94SC4 I did the reroute and PRESTO i have heat!!!.... Sucks that i cant just leave it like that though cause the weahter in Texas Changes so much.. It was in the twenties today and this weekend its supposed to be in the 70's!!.... i thought by doing this my A/C wouldnt work but it does!

 

Yes, it did the trick. I actually took my car to a mechanic to run diagnostics to make sure that was the problem before I bought the heater control valve.

 

My '93 SC4's heat stopped working a few days ago. Luckily, afternoons in NJ have been pretty decent weather-wise BUT going to work at 4AM was just straight up COLD.

Everything seemed to be working...

• Display worked and showed all data (i.e., temp, fan speed, etc.)
• Turning the temp **** showed the temp changing on the display
• Could hear and feel air

Just had no heat. Cool to cold air is all that would blow out.

Anyway, I searched the forum and found this thread which, thanks to 94SC4, had great pics on how to change hoses to get some heat back in the car. Ahhh, warmth!!
May not be a 100% fix but it will definitely get me through the rest of the winter or at least until I get enough cash to replace any defective parts.

Just thought I would revive this thread with my comments since it helped me out.

 

thanks ... this thread indeed did the trick for me .. till I can afford to buy the part I need

 

im about to do this also since my heat doesnt work either.

question tho. when u do this and if u turn down the temp on the climate control to 70, 75 or what ever its still going to pump out heat as if its on max heat right?

 

this didnt work for me? what else could it be? and its getting cold

 

I have the same issue as demented--I tried it and let my car run for about 5-10 mins and still no heat--does that mean my heater core is bad? ...though I dunno how a core could go bad unless someone put dexcool in my car when I wasnt looking and clogged it up lol. I want more detail about the VSV though-- 94SC4 said it controls the actuator on the control valve--could my actual heater core valve be bad and not the VSV?

Also, how much of a badass is it to get to the heater core valve? I noticed the heater core itself is directly behind my headunit next to the evap for the AC.( meaning no getting to it without removing the evap...)

 

the heater control valve is under the hood, near the firewall. its a lot easier to access than the heater core on the inside.

 

Thanks for the info and pics. I have intermittent heat and am going to try the test.

BTW, 94SC4, assuming the test works, how do you know if you need the VSV or the entire water control valve unit ?

Thanks