P1131, P1151, back of throttle body and intake manifold COATED in oil...
11-08-2012, 01:02 AM
#1
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P1131, P1151, back of throttle body and intake manifold COATED in oil...
Howdy everyone,
I have a '98 Ford F150 with 168,000+ miles on it and during a recent road trip my normally reliable steed gave me something to worry about.
About twenty miles into a 300 mile road trip, my truck began acting as though it had both a vacuum leak and a fuel delivery issue. Absolutely no power, I had to shift manually and could not get the engine under load to rev over 2000 RPM. I was able to finish the trip on a limp, let it sit over night and the problem almost seemed to fix itself. However, in a week the problem returned sporadically and within two weeks it was here to stay.
I went to a local auto parts store to have the DTCs checked and it told me P1151 and P1131, both of which indicated "vacuum leak detected." However, a Google search indicated it may be the O2S trying to correct a rich condition. I popped open the hood just to make a good visual check before I started throwing parts at it and sure enough, I heard a good hissing noise coming from what seemed to be around the throttle body to intake manifold gasket. When I went to change the throttle body gaskets I noticed the back of the throttle body blade and as far down as I could see inside the intake manifold was coated in oil. I cleaned as far down as I could, installed the new gaskets, cleared the codes and the problem got negligibly better.
Right now, the drivability of the truck is complete s---. Before I even attempt to drive it, I have to let it warm all the way up to closed loop. Shut it off for two minutes, re-start it then drive. Mileage is pitiful, I have no overdrive if I'm trying to get up a hill or pass anyone and I don't even try the interstate. I still have to shift manually, letting up off the throttle to get from manual 2nd to 3rd.
Work has been slow and I cannot afford to take it to a shop right now.
I have a '98 Ford F150 with 168,000+ miles on it and during a recent road trip my normally reliable steed gave me something to worry about.
About twenty miles into a 300 mile road trip, my truck began acting as though it had both a vacuum leak and a fuel delivery issue. Absolutely no power, I had to shift manually and could not get the engine under load to rev over 2000 RPM. I was able to finish the trip on a limp, let it sit over night and the problem almost seemed to fix itself. However, in a week the problem returned sporadically and within two weeks it was here to stay.
I went to a local auto parts store to have the DTCs checked and it told me P1151 and P1131, both of which indicated "vacuum leak detected." However, a Google search indicated it may be the O2S trying to correct a rich condition. I popped open the hood just to make a good visual check before I started throwing parts at it and sure enough, I heard a good hissing noise coming from what seemed to be around the throttle body to intake manifold gasket. When I went to change the throttle body gaskets I noticed the back of the throttle body blade and as far down as I could see inside the intake manifold was coated in oil. I cleaned as far down as I could, installed the new gaskets, cleared the codes and the problem got negligibly better.
Right now, the drivability of the truck is complete s---. Before I even attempt to drive it, I have to let it warm all the way up to closed loop. Shut it off for two minutes, re-start it then drive. Mileage is pitiful, I have no overdrive if I'm trying to get up a hill or pass anyone and I don't even try the interstate. I still have to shift manually, letting up off the throttle to get from manual 2nd to 3rd.
Work has been slow and I cannot afford to take it to a shop right now.
11-08-2012, 07:35 AM
#3
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That's what a catch can is for, but you may have a bad PCV valve. Sounds like you're building up too much pressure in the crankcase (too much blow-by ?) and blowing excessive crankcase vapors into the intake. Do you have a catch can ?
Last edited by thiggins; 11-08-2012 at 07:38 AM.
11-09-2012, 12:36 AM
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Nope, not all wet around intake manifold and coolant level is still full (but in desperate need of a flush). A freelance mechanic I know checked it out and thinks the EGR valve maybe stuck open causing a leak in the EGR plumbing somewhere.
I did replace the PCV valve, but the hose does look a little old. I'll replace that next just for the hell of it.
I did replace the PCV valve, but the hose does look a little old. I'll replace that next just for the hell of it.
