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I thought I had solved this problem, but it's still there...
Sometimes, if I touch the purge canister valve a I can feel a popcorn-like pulsation gong on inside....but then it smoothes out and I can't duplicate it. So I replaced the valve, but I am still having this issue.
I took my stethoscope out to see if I could figure out where this initiates and I can feel it here:
That's in the valve itself, the hose underneath it, which is hard to see in the picture, and it seems to start in the hose that connects to the engine up top
You might want to check for intake leak when the vacuum isn't high enough to keep a steady vacuum on pcv valve. It will flutter like that. Has it been tuned up lately
Spike, odds are, your leak is from somewhere else. The Purge Valve as I recall will pulse like you are seeing as it is attempting to draw a slight vacuum on the gas tank to do a leak check of the gas tank. You can prove this by simply filling up the gas tank (or anything above 3/4 of a tank). The computer will not check for a leak when the gas tank is really full. Besides, if the valve is having to cycle too much, it will throw up a code (P0456 as I recall) indicating a leak from the gas tank and that it is an emissions issue.
As for finding the leak, you have 2 options. If you smoke cigars, then this is the troubleshooting for you. With the car cold and the A/C off (ie, you don't want the engine fans running), start up the engine and take a few good drags off of the cigar and gently blow the smoke around the engine (intake area specifically). What you are looking for is the smoke to be gently moving along and then suddenly make a sharp turn. Where the smoke goes suddenly is your vacuum leak. Keep in mind the other 2 of the big 3 leakers for the X-Type. From there, I would be looking at the connection for the purge valve line going into the top of the engine. People have been known to have issues with that line (which may also help explain the cycling that you are seeing).
Option 2 is to pull out some starting fluid/ether. You then spray each joint in the intake. When the engine RPMs pick up, that is the location of your leak. I am not a fan of this method as you are spraying a flammable liquid onto a hot engine. Just keep sparks away, doing it in a well ventilated area, and all is good.
By the way, are you getting P0171 and/or P0174. This may also help narrow down where the problems are.
Spike, odds are, your leak is from somewhere else. The Purge Valve as I recall will pulse like you are seeing as it is attempting to draw a slight vacuum on the gas tank to do a leak check of the gas tank. You can prove this by simply filling up the gas tank (or anything above 3/4 of a tank). The computer will not check for a leak when the gas tank is really full. Besides, if the valve is having to cycle too much, it will throw up a code (P0456 as I recall) indicating a leak from the gas tank and that it is an emissions issue.
As for finding the leak, you have 2 options. If you smoke cigars, then this is the troubleshooting for you. With the car cold and the A/C off (ie, you don't want the engine fans running), start up the engine and take a few good drags off of the cigar and gently blow the smoke around the engine (intake area specifically). What you are looking for is the smoke to be gently moving along and then suddenly make a sharp turn. Where the smoke goes suddenly is your vacuum leak. Keep in mind the other 2 of the big 3 leakers for the X-Type. From there, I would be looking at the connection for the purge valve line going into the top of the engine. People have been known to have issues with that line (which may also help explain the cycling that you are seeing).
Option 2 is to pull out some starting fluid/ether. You then spray each joint in the intake. When the engine RPMs pick up, that is the location of your leak. I am not a fan of this method as you are spraying a flammable liquid onto a hot engine. Just keep sparks away, doing it in a well ventilated area, and all is good.
By the way, are you getting P0171 and/or P0174. This may also help narrow down where the problems are.
Thanks !!
So it's normal for the valve to pulse right after start up? That's when I have been testing it
Spike, yes. The car is going through its checks to see if everything is how it should be. Hence why I say to fill up the gas tank. This will cause the computer to not check the purge system.
You say you have a vacuum leak issue. What code(s) are you getting. The P0171 seems to be tied to some parts of the vehicle while the P0174 to others. This may help to go after specific things.
Well, I was getting a P0455 purge canister valve code, and I was having shifting issue, and I noticed the valve pulsating. I replaced the valve and also the brake vacuum hose and cleared the code and it did not come back and the shifting became normal again.
I decided to check the valve again a couple of times and noticed it was still pulsating and then smooths out, but I always check it right after I start the car, so apparently that's normal....so I may not have a leak at all