ive read it's a delay valve, and also i've read it's a pressure release valve.. but the books are sketchy at best




one line has a vacuum on it, and the other line leads to the double throttle diaphram..

the MAIN problem here, is my car has a rough idle. this "valve" does NOT leak when cold, but when it's hot it IS blowing (or sucking) air out (or in) through the tip area of that device..

look on your car for THAT, and there should be two vacuum lines that run up to it

we checked Amur_'s car, and his does not leak when warm.. mine leaks.. but not when cold..

*props to Amur_ for taking the pics *

what do you guys think? can anyone identify this device? anyone else have a leaky one? should i check for a leak when its running cold?

 

Note: we located the leak using our ears and then a garden hose. The leak is definitely coming from inside the tip and not either of the vac lines.

 

something to do with the cold start assist/ thermowax.....do the TB mod and get rid of it!!!!!!!

 

thats what i was thinking, because it doesnt suck air when cold, but it does when hot.. which suggests fast idle related..

either way, there shouldnt be a vacuum leak..

just curious to see if anyone can give this device a name, and what its proper functioning range would be..

 

Yep, it's the thermovalve that closes the #2 secondary throttles until the engine warms up. It's different to the cold-idle thermowax, which raises idle speed until the engine warms up, but uses the same coolant flow.

 

what if you dont have any vaccum lines hooked to it,and its capped off?Will it affect anything?Im in the process of putting my motor abck in and did away with the vaccum rack so im running out of vaccum ports off the intake to hoke these lines back up.

 

If you are thinking of removing the doing the TB Mod, just remove the Secondary Throttle Plates your gains are there anyway.

Removing the Water Thermo Valve/Cold Start will be a real pain, considering our climate.

I did the FULL TB Mod on a spare TB and hated It.

 

we took off the lines from it and capped them, and the car stalled way more frequently than before.

we also tried having a hose connector to hook them up and let air travel through, and it again, stalled more frequently..

well this car is my summer car (just got it) and im using the cavalier as a winter beater.. so im open to suggestions.. id still prefer a high idle when i start it up though, so it gets warmer faster..

but at NO POINT should this valve leak? i havent seen anyone elses leak like mine when warm..

 

Have you looked in the FSM? There's enough info there to work out how the thermovalve should be connected up. If it leaks out the little filter on the end when warm, it's either broken inside or the vac lines are connected wrong. One if the vac lines goes to the manifold, so if this line's on the wrong port on the thermovalve (or not on anything), you'll have a vac leak that'll upset your idle.

 

i looked in the FSM, the information i was getting was scarce..

ill try reversing the lines.. and try getting a new one..

BUT according to the FSM, the line coming from the diaphram is correct.. i think..

i dunno.. ****.. ill look again..