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This cannot be right vacuum line wise...2001 3.0 5 speed with A/C The 90* elbow does not fit on the nipple of the vacuum solenoid thing but i cant figure out how else it would operate if it wasnt... Also what exactly does this do?
Also poking around looking for possible vacuum leak areas - are there any common areas this can happen? I dont see a whole hell of alot of vacuum lines. Whats the best way to go about hunting for vacuum leaks? I had the truck all warm a few months ago and unplugged the IAC valve and it did drop below 500 RPM. I just did it again last night after changing the fuel filter and letting it idle 15 minutes (temp was normal area) and it hardly dropped (maybe to 6-700) with a light bit of surging. Going to actually drive it around getting it hot and try again to verify.
Looks like someone disconnected it and the line is just stuck on the linkage tp prevent a vacuum leak.
Although from the sounds of it, it doesn't fit on there very well.
I don't have AC on mine, but I think it connects to where the arrow is on my screen shot.
How that works is when the AC is on, the vacuum line becomes activated to pull the water tap closed.
Under normal conditions, the tap remains open all the time.
yea thats what i thought but its loose as a goose on there. I bet that diaphram has a vacuum leak and someone just did that to "fix" it and stretched the elbow all out. The AC works OK but never gets super cold to the point i have to turn it down that would explain it haha.
what would you call that diaphram part? NVM - heater control valve
Last edited by Dngr Rngr; Oct 3, 2018 at 11:34 AM.
To go hunting for vacuum leaks... I'm in the same boat, so this is what I've been doing.
Rather then checking every line for a vacuum leak, I work in reverse by disconnecting all the vacuum lines from the upper intake manifold and blocking those ports off.
There are a few of them.
The brake booster port _ easy to see at the back of the upper intake manifold.
The main vacuum feed that runs the dash switches, EGR system etc. That is found at the back of the upper intake manifold near the brake booster port. It's out of site and can be made accessible once the line from the brake booster has been disconnected.
It has a large boot with a number of coloured lines from it, yellow, green and red.
Another port is at the front of the upper intake manifold near the EGR valve.
It's down low, sort of out of site, near the front, below the EGR valve where the port is on the manifold.
The port itself is for the EVAP system.
The last port, the one that causes the most problems and the least accessible is for the PCV valve itself.
It's totally located out of site pretty much above the middle of the valve cover on the drivers side.
There is a hose (that usually gets hard and can crack) that runs from the port to the PCV valve itself at the back of the valve cover on the drivers side.
The PCV valve plugs into a large rubber grommet in the valve cover, that grommet either gets hard or soft and rotten. It needs to be checked as well as the PCV valve.
There is also an O-ring on the bottom of the dip stick tube that seals on the block, this is also a common source of vacuum leaks.
On the other valve cover where the oil cap is, there is a breather line that goes into the air tube, check that for leaks and cracks, that is also part of the PCV system.
As I said before, I disconnect all that and block all the ports off, and then I unplug the IAC valve.
The trucks idle should fall below 500 rpm and/or stall.
If it does not, then you have eliminated all those systems as a possible cause and you need to look elsewhere.
If it does, then start plugging things back in, one at a time and work backwards.
In my case, I have a leak in the crank case vent system somewhere.
Right now, I'm driving with out it connected, the crank gasses are just venting out side until I have time to find where the leak is.
yea thats what i thought but its loose as a goose on there.
The one on my truck is too. Doesn't make any difference in the way my truck runs. If it's really bothering you, you could maybe dab some sealer on the nipple inside the valve to keep the elbow from coming out. But honestly, even on rough trails the one on my truck has never just fallen out on it's own.
This one would fall out just sitting there. Anyways bought a new variety pack of elbows and a new control valve just in case it leaked. Put a good fittign elbow on, manually moved diaphram in, plugged the elbow and it held for a good minute with no movement. Once I removed my finger it opened the valve again.
One problem down - just gonna return the valve.
Found the fat line to the evap valve thing crusty as ****. Also why is it in 2 pieces and a 90* elbow in the line? One single piece of fuel line about a foot long will work just fine... Brake booster line wasnt exactly snuggly sitting on the intake so gonna replace that too. The small hardlines look OK. Will have to climb on top the engine to see the backside.
does anyone know why the arrow on the heater control valve is pointing in the opposite direction of the heater core inlet flow direction? the coolant travels up from the manifold to the heater core and then out down the heater core outlet hose. e.i., the arrow is pointing to the front of the car and the coolant travels toward the cabin.
This never made sense to me. I figured it was referring to the flow direction of the coolant passing through the HCV. Maybe it's referring to the vacuum direction?
ty.
by "water tap" you mean coolant supply right? basically the heater control valve shuts off the heating /cooling from the circulation of the coolant and allows the air compressor to cool/heat when A/C is on. right? ty.
Looks like someone disconnected it and the line is just stuck on the linkage tp prevent a vacuum leak.
Although from the sounds of it, it doesn't fit on there very well.
I don't have AC on mine, but I think it connects to where the arrow is on my screen shot.
How that works is when the AC is on, the vacuum line becomes activated to pull the water tap closed.
Under normal conditions, the tap remains open all the time.
The Vac hose your looking for is in your picture. It's the small gray line with the black connector sticking on top of its piston control arm (whatever you call it) projection behind the HeaterControlValve. Hope you found! Looks like someone put it there so they could find it later but forgot the reattach it.
