Problem with my 2001 Pontiac Grand Prix GT
3.8 L V-6 (non-supercharged)
My Service engine soon
GM Computer codes = p0108
Repairs done prior = Just replaced the upper intake manifold.
GM tech = KK
question = I have a 2001 Grand Prix GT (non-supercharged). I just replaced my
upper intake manifold due to warping causing a coolant leak. After putting
everything back together I have a problem with the vacuum system. At idle when
I take off the oil cap there is way to much suction coming through. It pulls the cap
back hard. When I cover it with my hand the engine RPMS go way up and it
sounds like the vacuum is starving for air. Is it possible that while replacing the
upper intake I spilled coolant into the tube leading to the PCV valve? I checked
all vacuum lines and they seem to be all right and hooked up correctly. Also I
did not use any extra sealant on the gaskets as I heard this can cause problems.
Why does my GP doing this.
KK:
Only thing that can cause this vacuum problem and the MAP sensor code is that
either you did not install the PCV valve, the valve O ring is missing, or possible
the large plastic insert is not in the new manifold. It should have come with this
insert. Look at the inside of the old manifold and you will see a runner insert that
can be removed. If this was missing from the new manifold, it could cause this.
Be sure the PCV valve is installed. Getting coolant in any tube or passage would
not cause this.
3.8 L V-6 (non-supercharged)
My Service engine soon
GM Computer codes = p0108
Repairs done prior = Just replaced the upper intake manifold.
GM tech = KK
question = I have a 2001 Grand Prix GT (non-supercharged). I just replaced my
upper intake manifold due to warping causing a coolant leak. After putting
everything back together I have a problem with the vacuum system. At idle when
I take off the oil cap there is way to much suction coming through. It pulls the cap
back hard. When I cover it with my hand the engine RPMS go way up and it
sounds like the vacuum is starving for air. Is it possible that while replacing the
upper intake I spilled coolant into the tube leading to the PCV valve? I checked
all vacuum lines and they seem to be all right and hooked up correctly. Also I
did not use any extra sealant on the gaskets as I heard this can cause problems.
Why does my GP doing this.
KK:
Only thing that can cause this vacuum problem and the MAP sensor code is that
either you did not install the PCV valve, the valve O ring is missing, or possible
the large plastic insert is not in the new manifold. It should have come with this
insert. Look at the inside of the old manifold and you will see a runner insert that
can be removed. If this was missing from the new manifold, it could cause this.
Be sure the PCV valve is installed. Getting coolant in any tube or passage would
not cause this.
/
Thanks KK.
You were right on. It was the bottom o-ring for the PCV valve. The new upper intake manifold
came with the top o-ring but not the bottom one and it was black rather than orange so I didn't see
it down there. After I put the bottom o-ring in the crazy suction was gone. But I am still getting the
same problem as I had before I replaced the intake. Code p0108. When cold the car will start, rev
up then stall. It will only stay running if I keep the RPMs at about 2000 till it warms up a bit. I think
the coolant leaking into the intake may have caused the MAP sensor to go bad. I am going to try
replacing it tomorrow. Unless you can think of something else that might be causing that issue.
Thanks again for your help! You were the first one to nail the answer!
You were right on. It was the bottom o-ring for the PCV valve. The new upper intake manifold
came with the top o-ring but not the bottom one and it was black rather than orange so I didn't see
it down there. After I put the bottom o-ring in the crazy suction was gone. But I am still getting the
same problem as I had before I replaced the intake. Code p0108. When cold the car will start, rev
up then stall. It will only stay running if I keep the RPMs at about 2000 till it warms up a bit. I think
the coolant leaking into the intake may have caused the MAP sensor to go bad. I am going to try
replacing it tomorrow. Unless you can think of something else that might be causing that issue.
Thanks again for your help! You were the first one to nail the answer!
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