What Is Wrong With My 2004 3.9 Motor?

Discussion in 'Other Auto Tech' started by 04V6Stang, Jul 30, 2012.

  1. The engine idles smooth, no trouble codes, but the engine surges at the mid to upper rpm ranges while holding the throttle steady. I have replaced the air and fuel filters, spark plugs and plug wires. Where do I need to look next?
  2. Toss a scan tool on it anyway. Often times you'll find pending codes that don't trigger the check engine light, simply because the problem doesn't persist long enough.
  3. Good point, I'll try it tomorrow.
  4. Checked it with my scan tool today, NO codes. What next?
  5. Manual or auto?
  6. Automatic, could it be a problem with a speed sensor?
  7. Check your fuel pressure under load. Could be a fuel pump going out.
  8. Got a #0316 trouble code today after starting for the first time, engine actually idled like crap until it warmed up. That code is not listed on the chart I have. Anyone know what it is?
  9. P0316 is a misfire on startup for the first 1000 revolutions. How many miles and when was the most recent tune-up done?
  10. 140,000. In the past two months, I have replaced plugs, plug wires, air filter and fuel filter. Before changing the plugs and wires I was getting a #3 cylinder misfire. After plugs and wires, no #3 misfire, but the mid to upper rpm surge was evident. Surge is still there after the filters were changed. #316 code was triggered for the first time yesterday.
  11. I have a fuel pressure gauge, but I don't see a stock fitting on the fuel rail to hook it to. How do you go about checking the pressure on this system, splice into the fuel line and install a gauge? Is the attached picture showing the regulator, if so, do you install the gauge before or after the regulator?

    Attached Files:

  12. Yeah don't splice anything, if there isn't a schrader valve on the fuel rail you can get an adapter to go inline before tw fuel rail. But let's not get ahead of ourselves, if you are getting a p0316 now id suspect your having an ignition related intermittent misfire. Check the coil. Sometimes they will get hairline cracks on tw bottom of them. I see it all the time.
  13. A couple of posts back I explained the #3 misfire code I had before replacing plugs and wires. Since then, no #3 misfire. At that time I suspected the coil, but didn't see anything wrong with it visually. Autozone claims that they can't test the coil pack, I didn't want to just swap it out on a hunch. Is there a way that I can test it out. Can the coil have an intermittent problem and not send a trouble code to the computer?
  14. Yeah with an intermittent misfire it might not set a code. No real way for a do it yourselfer to test the coil but I would still say that it is your suspect. They used that same coil on Taurus/ sable, rangers and f150s and they're easy to find in the junkyards.
  15. Just checked on Rock Auto, they have a Standard Motor Products unit listed for $30. I will probably go that route instead of hoping to find one in a wrecking yard with no issues.
  16. Installed the new coil from RockAuto. Problem solved, runs great now. Turns out there were a couple of small cracks on the back side of the old coil.
    JB04v6 likes this.
  17. buy a 5.0 lol
  18. Even my Peugeot has got similar problem.. i have changed fuel filters and water pump.. but no positive result.. I have checked my fuel pressure its normal.. now from few days there is a noise from engine and last night i found there is leakage from car.. Is it the Tank or Radiator am not sure or something else.. this engine is getting worst day by day.. i am totally fade up with it.. from last one month am try to fix it but at end of day same thing continues..
    now i have two options...
    1. should i change the engine??
    2. should i repair this??

    already i have wasted $1000 for this car.. any engine expert???
    can someone help me regarding this??

    peugeot maintenance