Heater switch valve question.

[Fubar231]

http://www.cygnusx1.net/Supra/Library/EPC/291420/catalog.aspx?F=8716&P=1

Part 87240. From what ive read this controls the flow to water to the back of the head. I know people have taken it out, to make it full flow at all times, which would in theory keep temps down, but what are the cons to this? My friend is running his currently with it bypassed and he said he gets some weird heating/cooling issues with his ac sometimes, but thats it. I can definitly have that as a trade off to keep the temps down at the back of the block near the firewall. Again, any input would be great!

Thanks,
Shane

 

[CRE]

The heater core has coolant flowing through it pretty much all the time as it is. You shouldn't really see any difference. The only time the heater core is bypassed is when the A/C is at full.

 

[Bri7man]

If it is bypassed wouldn't a/c run hot air always? Was talking to zumtizz about this since my heater control valve broke and replacing.

 

[cuel]

No, the blend door(between the heater core and a/c evaporator) controls that. Its how you can control the temp. of the air from the vents, as long as its all working correctly.

 

[jetjock]

You'll lose about 8-10 F of AC goodness at max cold but otherwise you won't notice. Remember, the climate control system was designed to maintain a set temp and the coolant valve is always open when doing that.

As CRE said the only time it's closed is when the head unit is set to 65 and even then the valve is designed to have a trickle through it. Still, I used to keep the control at 66 when I wasn't using AC or heat so as to keep the valve open. That way I could still get max performance when I needed it. A full time bypass would prevent that.

 

[Fubar231]

You'll lose about 8-10 F of AC goodness at max cold but otherwise you won't notice. Remember, the climate control system was designed to maintain a set temp and the coolant valve is always open when doing that.

As CRE said the only time it's closed is when the head unit is set to 65 and even then the valve is designed to have a trickle through it. Still, I used to keep the control at 66 when I wasn't using AC or heat so as to keep the valve open. That way I could still get max performance when I needed it. A full time bypass would prevent that.

So what your saying in the first paragraph, by losing 8-10F of ac goodness you mean it just wont be as cold? If so i can live with that since i don't use my ac anyways, (It sucks, i never recharged it, havnt got around to it, just dont use it)

The second paragraph, saying as long as the climate control thing is set to 66 the valve will be open all the way at all times? Then the lil segment after that your saying it would be full open to the heater core at all times if i removed it, but losing just a little bit of ac? Cause if so i can live with that. Quick question, if i did remove it, where does the vac line on it lead too and where would i block it off at?

Thanks for all the help and replies everyone!!

 

[jetjock]

If your AC is busted and you don't plan on fixing it (not to smart imo but it's your car) then feel free to bypass. You can block the vacuum line where it tees into the intake manifold. Not that you couldn't have eyeballed that yourself...

 

[mecevans]

just take the vac line off the switch and put it directly to the actuator thing. works great.