Vacuum lines on the thermostat?

[eyetrauma]

Does anyone know why there are vacuum lines running to the thermostat? I can't figure out what they could possibly do.

 

[Todd95TSi]

Follow the line to its source. If it is actually a vacuum line I would think it would cause you to hydrolock. Make sure it isn't the line to the overflow bottle.

 

[Talontid21]

if you are talkin' about the two that run right next to each other and into the thermo housing closley together,they are coolant lines

 

[Defiant]

Originally posted by eyetrauma
Does anyone know why there are vacuum lines running to the thermostat? I can't figure out what they could possibly do.

It's a thermal vacuum valve, only on Federal engines.

http://www.taboospeedshop.com/emissions.htm

It controls the actuation of the EGR.

 

[eyetrauma]

I knew it was emmissions related. Any idea if I disconnect them what state it will leave the EGR in? I assume open, because it looks like I'll need a EGR block off plate.

 

[crankbender]

Yep get the blockoff.

 

[Defiant]

Don't eff with the EGR:

http://www.ukcar.com/features/tech/Engine/techno/exgr.htm

 

[eyetrauma]

I've got a TSI awd I don't drive that much on the street, and a galant vr-4 I drive on the street a lot.

I may consider keeping the EGR while getting rid of all the other emissions related vacuum lines. I could still get rid of the charcole canister, purge convrol valve lines and purge solonoid lines. I can see how that works on my Talon. If it works well getting rid of everything but the EGR I may do it to my galant. But eventualy I'll probably block off the EGR in my talon. Good thing I've got a lot of vacuum line caps in the mail.

 

[boostedinaz]

I was having some idle and cold starting problems with my Talon. I tried a bunch of shit to fix it an none of it worked. I went to rebuild the TB and found that my Vacuum lines had small cracks in them. I went to Taboo's site and removed as many as I could. My hard starting went away and I no longer have idle problems. i will also have to disagree with the EGR I have them blocked on all my cars and they run better and have a better chance of keeping vacuum leaks away.

Michael

 

[92redman]

Didn't feel like reading Defiant's article, but besides having an affect on gas mileage, the EGR also reduces knock because it reduces cylinder temps. Not saying it would be that noticeable but still, if it is working why not leave it hooked up?

 

[eyetrauma]

I don't think the EGR is open under boost so I don't think it would affect knock there. The EGR inceases intake temps, by heating up the intake manifold and dumping hot exhaust into the intake, so I don't know how it would lower cylinder temps.

Mostly I want to get rid of as many vacuum lines I can to prevent leaks, and simplify the intake system and engine bay as much as possible. And if I get rid of the vacuum lines and the carcoal canister I can save like a hundredth of a pound of performance draining weight.

 

[92redman]

It lowers cylinder temps by displacing oxygen, that is also how it helps fuel economy. If you read the article I am sure it explains it all.

 

[bulletproof96]

I have a 93 eclipse 2.0 non turbo and i was rebuilding the engine and then i found that on the thermostat housing it was to openings next to each other that look like vacuum lines i can't follow to where it goes because nothing is there now. So can someone please tell me if the lines go to the overflow resevoir or radiator iteself or somewhere else? thank you

 

[nightspeed87]

I dont have any vacuum lines at all for any of that egr stuff, no charcoal canister, and my egr is still on the car but I stuck two screws into the two holes coming off of it ( a cheap way to block it off I guess. ) Anything wrong with this as far as changing the idle, engine characteristics ( not emissions related) Just curious, despite ive had it like this for a long time.

 

[Thomas91169]

Thermal Control Valve

i know this because i just had to replace mine, the plastic had become so brittle it just snapped when i tried to pull the hoses off. i should be getting my replacement tomorrow.

btw, dont #### with EGR shit. theres no gain and no loss from having it work correctly, so just leave it alone.

 

[nightspeed87]

The gain for me is cleaning up the engine bay from unnessecary stuff.

 

[crensinivon]

There is a broken vaccum switch on the thermostat housing. I was wondering if this switch is important or can it just be taken out of the loop. Also, what does it do so I understand what it does if it causes problems.

 

[Spades]

It is called a thermovalve which operates the EGR

 

[crensinivon]

So if I'm blocking off the EGR then I shouldn't need to worry about it then thanks.

 

[Defiant]

It only operates when the engine overheats.

 

[Spades]

It only operates when the engine overheats.

the thermo valve or the EGR system as a whole?

 

[Defiant]

The switch which is the thread topic.

 

[steve]

It only operates when the engine overheats.

Pretty funny, Guy.

The thermoswitch (the one with the vacuum lines not wires) on the thermostat housing is there to disable the EGR operation before the engine has warmed up. If you not using the EGR then it just serves to seal the housing.

 

[pj91gsx]

Thomas91169, my thermostat control valve thing broke too. My motor overheats after about 15 min of driving. Also it leaks coolant out of the oil filter housing coolant hoses. I just replaced the hoses and the clamps prior to running the motor. how much was the replacement? since my line broke i just left it unattached. so its a vacuum leak.

 

[M3BEAST]

It's a thermal vacuum valve, only on Federal engines.

http://www.taboospeedshop.com/emissions.htm

It controls the actuation of the EGR.

mines broke and the plastic thing is emissions for egr

so can i just unbolt it and put a bolt thru there to block it off since i have an egr blockplate already.

thanks man

thanks i found it. no egr= eliminate thermovalve switch