601LEXTACY

Hey new issue. Its gettin cold here in Mississippi and for some reason my 91 is acting like it doesnt know what warm air is. It has completely expanded what it thinks hot air is. I try to wait until the car is warm but after like an hour of continuous driving only then will it try to get warm. What do I need to replace to fix this and can I do it myself. Let me know wassup guys.

GRAND_LS 4

iTrader: (2)

1. Make sure your coolant fluid is topped.

2. Does your temp gauge go to about the middle after 10mins of driving?
If it doesn't, that most likely means a new thermostat will due.

601LEXTACY

It is and It does. So whats the next option. Hurry. I am freezing here.

GRAND_LS 4

iTrader: (2)

Not sure what your problem is then. having said that, IF its the same as teh SC400, there are two lines in the engine bay that you can swtich to regain back some heat.


Have a read here:

https://www.clublexus.com/forums/sho...ht=heater+line

https://www.clublexus.com/forums/sho...ht=heater+line

There are some pics to the lines you switch to cause the heater core to kick in, the reason for it not kicking in is usually a bad heater valve.

there are some thread with pics, but i cant seem to find them... have a further look in the SC forum.

GRAND_LS 4

iTrader: (2)

found it...........

601LEXTACY

But I have an LS. Will that work for me. I dont see these parts under the hood also.

GRAND_LS 4

iTrader: (2)

Its somewhat of a common issue on the SC400, which i thought might be similar to the first gen LS. If you cant find them, then I'm not sure what might have gone wrong.

sorry i couldnt be of anymore help.

justfixit

LS400 does have the heater control valve but it doesnt work or look the same as SC400. It is located on passenger side firewall. Usually this valve will leak a little coolant (you will see flakey residue) and this coolant will run down the heater control cable and cause it to bind up. When it binds up it will not open air mix door inside vehicle. If you look under dash on passenger side above transmision tunnel you will see cable. Check cable movement as you raise and lower temperature setting on climate control panel.
Good luck

601LEXTACY

Ok. Found it. And this is what it looks like. Is this the source of why i dont have any heat or as much as i should?

justfixit

Yeah you found it. If you will notice, there is a cable connected to the valve that moves (or should move) as you adjust temperature up and down. All that reddish colored substance on the valve is coolant leaking and that coolant will run inside of the cable causing it to seize up. Seized cable means no heat.