johnathan1 said:
This procedure will check the VSV and determine if it is mechanically functioning (meaning does it open and close) You will need a small section (1 or 2 ft is fine) of 1/4 inch vacuum line.
(1) engine off
(2) locate the VSV and remove the small 1/4 inch vaccum line at the top of valve (the metal "cap")
(3) attach your 1 or 2 ft section of 1/4 inch vacuum tubing to the VSV.
(4) place the open end of the tubing you just attched to the VSV and place it in your mouth (YES that is what I said!!!
)(5) SUCK, DRAW, OR CREATE A VACCUM (whichever word choice you prefer) on the tubing and observe the VSV where the little plastic arm is located below the metal cap where you just attched the tubing. When you suck/draw/create a vaccum on the VSV you should notice the little arm move upwards and "open" the valve. Release the tube from your mouth and the arm should "snap" back to it's lower "closed" position. The amount of "sucking" you will need to move the valve will be something similiar to drinking a VERY thick milkshake. (Mmmmmmm milkshake!!!) The total movement of the arm is about the diameter of the coolant hose or about 3/4 of an inch. If you go red in the face while sucking before you see movement or no movement happens or the arm only moves 1/4 inch instead of the full range, then the valve is stuck and/or doesn't operate properly and you will need to replace the valve. Also, the valve should REMAIN in an "open" position (little arm upwards) with constant vaccum applied and not slowly move downwards. If this happens then the diaphram in the "metal" top of the valve is leaking and not holding a vaccum and again, you will need to replace.
..So,...... If you have followed the previous steps and the VSV is mechanically working as it should. You can now try this....and what you will be doing here is making sure coolant flows into the heater core and you get HEAT from the vents.
(1) with a vaccum applied to the VSV using the method described above. Keep the VSV in an "open" position by clamping the tubing that was in your mouth with a vice-grips, or similiar, so you keep the vaccum on the valve. (I actually use 3 ft of tubing, open the passenger side door, place the end between the end of the door panel and the end of the fender and close the door and this pinches the tube nicely).
(2) start engine and let it warm up. Since you have the VSV in a fully "open" position, there should be coolant flowing into the heater core. You may or may not actually hear the waterfall sound at this point (depending of course on whether or not you have air in there), but give it some gas (which turns the water pump and thus moves the coolant) and you should hear the waterfall sound. Once the car warms up you should, likewise, have warm air out the vents with the blower on and since you have "bypassed" the heater controls by forcing the VSV to be in an "open" position, it doesn't matter what they are set at.
(3) Now, once the engine is warm and if you STILL don't have warm or hot air out the vents, or air is hot at first then cools, first check to make sure the VSV is still open and your little vaccum hose has not fallen off, or lost it's vaccum. If your VSV is "open" then you have a blockage somewhere which is not allowing coolant to flow THROUGH the heater core; meaning, there is a hose blocked on the inlet and/or outlet side of the heater core, the heater core itself is blocked (filled up with corrosion or gunt from years of old coolant), or worse yet you have a blockage in the block which is restricting the flow of coolant and in this case you will, if not already, have other major engine problems .....or of course you are a total idiot and have no coolant in the engine at all..... WOW what a run-on sentence !!1 :icon_bigg
So let's recap what has been done at this point in summary....
(1) VSV checked for mechanical operation (does it open and close properly?)
(2) does coolant flow through the heater core (hot air out the vents?)
Finally the question must be asked at this point...IS there a properly working vaccum to the VSV????
Now,... the operation of the VSV is controlled by a vaccum which is controlled by the heater controls on the dash relative to the ambient cabin temperature. Remember that first little vaccum tube that you removed from the "top" of the VSV valve way back at the beginning of this long-winded post?? It is a 4 inch section of tubing that connects to a electro-mechanical switch underneath the metal "top" of the VSV. Take a look at the switch for a moment (on my car it is blue in color)... It has two wires comming off of it, and two vaccum tubes as well. One of the tubes attaches to the "top" of the VSV which is the one you removed initially. The other tube runs to the other side of the engine compartment and to other various components. This tube is where the vaccum comes from to operate the VSV.
First thing to check here is...
(1) With engine running at normal operating temp. If you remove the tube from the electro-mechanical switch under the VSV that runs to the other side of the engine compartment, there SHOULD be a vaccum that you can feel with your finger and you can actually hear it drawing in the ambient air. If there is a vaccum, this is GOOD and means that you have the vaccum present to operate the VSV. If there is NO vaccum, then here is a problem and you must trace the tube back and find out why there is no vaccum. If this is happening then there will be no vaccum at the electro-mechanical switch and thus no vaccum can be applied to the VSV, thus it will not open and you will not have heat....Next
(2) Now to the electro-mechanical switch under the VSV ( has the two wires comming off it and a connector nearby). This is controlled by the heater dash controls when you increase/decrease the temperature in the passenger compartment. When you desire to increase the temperature of the air into the cabin, the switch opens via a electric current and allows the vaccum in step#1 above to be applied to the VSV which opens the VSV and allows hot coolant into the heater core resulting in heat into the cabin. Likewise, a desired decrease in cabin temp will shut the switch off and remove the applied vaccum to the VSV, thus closing the VSV and stopping hot coolant from entering the heater core. OK....time for lunch. Hope this does help someone out there...
Cheers,
Rick..
