Help diagnosing P0171/P0174 codes please

[dhollow2]

I have a 2000 Windstar with the 3.8l engine and 129,000 miles on it. I have been trying to diagnose 0171/0174 codes and have a question about a whoosh I hear when I goos the throttle manually. At first I thought this was caused by a vacuum leak somewhere around the upper intake manifold, but the sound is resonating from the intake manifold cover itself. This is apparent if I put my ear directly on the plastic cover. Please see this video: http://youtu.be/RD8xEsD5jz0 which clearly illustrates what I am hearing. My question is: Is this sound normal? I've not heard this before but I haven't ever manually goosed the throttle from under the hood like this before. I just want to make sure I'm not chasing a Red Herring.

I have checked the periphery of the cover and there are no leaks. I have triple checked all of the vacuum lines and fittings and cannot find any leaks other than a small one at one of the IMRC bushings, which seems to be normal. The van has had the valve cover/isolator bolt TSB performed previously. I've also cleaned the MAF sensor, checked the EGR valve, and replaced the DPFE sensor.

Thanks!

[tempfixit]

Originally Posted by dhollow2

I have a 2000 Windstar with the 3.8l engine and 129,000 miles on it. I have been trying to diagnose 0171/0174 codes and have a question about a whoosh I hear when I goos the throttle manually. At first I thought this was caused by a vacuum leak somewhere around the upper intake manifold, but the sound is resonating from the intake manifold cover itself. This is apparent if I put my ear directly on the plastic cover. Please see this video: http://youtu.be/RD8xEsD5jz0 which clearly illustrates what I am hearing. My question is: Is this sound normal? I've not heard this before but I haven't ever manually goosed the throttle from under the hood like this before. I just want to make sure I'm not chasing a Red Herring.

I have checked the periphery of the cover and there are no leaks. I have triple checked all of the vacuum lines and fittings and cannot find any leaks other than a small one at one of the IMRC bushings, which seems to be normal. The van has had the valve cover/isolator bolt TSB performed previously. I've also cleaned the MAF sensor, checked the EGR valve, and replaced the DPFE sensor.

Thanks!

Have you tried a smoke test for vacuum leak??? Check this video out, it maybe helpful.

http://www.youtube.com/watch?v=zMok2...7&feature=plcp

[dhollow2]

Thanks for the video link. I thought about a smoke test but don't have access to a machine. The cigar method looks easy so I'll probably give it a try. I really don't expect to find a leak, though. I've been over every possible leak point and mating surface with both a propane torch and carb cleaner and only found the small leak at the IMRC bushing. I also isolated the aux vacuum system, brake booster, egr valve, and evap solenoid to no effect. Overall system vacuum is steady at 20 inHg with appropriate response to the throttle. Fuel pressure is good at 33 PSI. All of the spark plugs looked good and are correctly gapped. The van idles smoothly and accelerates with good power and no hesitation or stumbling.

I pulled the intake plenum and the EGR ports were 90+ percent clear. I was surprised to see that the sleeves on the isolator bolts were BLACK. The van had the isolator bolt TSB performed by a dealer at 36k miles and I thought the updated sleeves were supposed to be GREEN. I haven't seen any posts about repeated failure of the isolator bolts, but since they are black I'm wondering if the TSB was done with the old level bolts. Can anyone confirm if the upgraded bolts are always green, or could they be black?

[MARZBX157]

If I remember correctly, the new bolts are green shouldered.

[ricebike]

http://www.f150online.com/forums/199...174-codes.html

how about the pcv and hose condition?

then on page 3:

it turned out my exhaust flanges were a little loose at the manifolds. i never paid any attention because it didnt make any noise once the metal warmed, it quieted up..

exhaust leak would cause those codes to come on?!?

[dhollow2]

The PCV valve and hose are both in good shape. I hadn't thought about an exhaust leak, although that seems unlikely since both banks are lean. I'm not sure about the isolator bolts now either. The picture of the bolts on the Rockauto site are green with black on the top part which would be visible when installed. I'll have to pull one and see if it's green or black.

[tempfixit]

Have you found the problem and come up with a fix??

[dhollow2]

I wish I could say definitively that I have, but I ended up resetting the codes and so far no CEL. We've driven the car over 400 miles with 30+ drive cycles since I reset the codes. I'm going to be optimistic and hope I snugged something up without realizing it.

[Searles Lewis]

Originally Posted by dhollow2

Thanks for the video link. I thought about a smoke test but don't have access to a machine. The cigar method looks easy so I'll probably give it a try. I really don't expect to find a leak, though. I've been over every possible leak point and mating surface with both a propane torch and carb cleaner and only found the small leak at the IMRC bushing. I also isolated the aux vacuum system, brake booster, egr valve, and evap solenoid to no effect. Overall system vacuum is steady at 20 inHg with appropriate response to the throttle. Fuel pressure is good at 33 PSI. All of the spark plugs looked good and are correctly gapped. The van idles smoothly and accelerates with good power and no hesitation or stumbling.

I pulled the intake plenum and the EGR ports were 90+ percent clear. I was surprised to see that the sleeves on the isolator bolts were BLACK. The van had the isolator bolt TSB performed by a dealer at 36k miles and I thought the updated sleeves were supposed to be GREEN. I haven't seen any posts about repeated failure of the isolator bolts, but since they are black I'm wondering if the TSB was done with the old level bolts. Can anyone confirm if the upgraded bolts are always green, or could they be black?

I checked the fuel filter on my car, looked like the original, and I had a shop and others supposedly replace numerous times. It did not look like it had ever been replaced, at all. Mechanics get pressured to lie by their bosses a lot.

That having been said, I have the 2-year warranty Resniz bolts, and have read numerous posts here back to 2005, and all state they are green. BTW, I have the upper crankcase popping sound, and prior posts to here seem to indicate even if the isolator bolts are replaced, especially if it is early in gas mileage, they might have to be replaced again.

They are always green. Mine looked green, I am going to replace them tomorrow using he leckemby procedure. Another thing that goes, even in new replacement parts, is the coil pack.

HTH!

[Searles Lewis]

Originally Posted by dhollow2

The PCV valve and hose are both in good shape. I hadn't thought about an exhaust leak, although that seems unlikely since both banks are lean. I'm not sure about the isolator bolts now either. The picture of the bolts on the Rockauto site are green with black on the top part which would be visible when installed. I'll have to pull one and see if it's green or black.

Then you might as well replace them all. They supposedly shatter when taken out! At least they are weak.

[12Ounce]

Originally Posted by dhollow2

...... I was surprised to see that the sleeves on the isolator bolts were BLACK. The van had the isolator bolt TSB performed by a dealer at 36k miles and I thought the updated sleeves were supposed to be GREEN. I haven't seen any posts about repeated failure of the isolator bolts, but since they are black I'm wondering if the TSB was done with the old level bolts. Can anyone confirm if the upgraded bolts are always green, or could they be black?......

Yes, the "upgraded" bolts were always green .... but not all the "replacement" bolts were green!

It took Ford a while to get their hands around this problem .... so a number of replacements were made using the original quality black bolts. I did my first repair using black bolts .... sure enough, in a year or so, I was back in there doing it again. Luckily, the green bolts were available for my second repair.

Be sure not to overtorque these bolts ... does no good ... can do mucho harm!

[dhollow2]

Update... About a thousand miles after resetting the CEL, and the day after a 600 mile drive from Atlanta to Washington, DC, the CEL came on again. On the return trip from DC, the transmission also set a fault code so I had a transmission shop read the codes. That's another issue to be resolved later, but they also reset the codes (probably so I couldn't take it anywhere else for a second opinion). Over the next couple of weeks several seemingly unrelated issues showed up (backup sensor fault, auto sliding doors occasionally not opening/closing, intermittent rough idle) until one day a message something like "low system voltage" flashed briefly on start-up. I replaced the battery and all of these unrelated problems went away. We've logged another 1,500 miles without another CEL so I'm going to assign the blame for all of this to a weak battery.