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Volkswagen Jetta Engine Questions



  • MrShift@EdmundsMrShift@Edmunds Posts: 43,693
    edited May 2012
    You should be able to pop the cover off the fuel pump---then briefly crank the starter motor or have someone do that (work safely!). You should hear the fuel pump start up audibly. If it doesn't, then I'd check the fuse circuit for the fuel pump (I think it is #G6) and if that's okay, then the fuel pump relay is suspect.

    You can also check for fuel in the fuel rail by depressing the little Schrader valve under the hood (wear safety glasses to protect your eyes).
  • bpeeblesbpeebles Posts: 4,083
    I can pretty-much GUARANTEE that your no-start problem is not caused by fuel-filter.

    You should be able to hear the fuel-pump run for about 3 seconds if you turn the key to "ON" without cranking the engine. (Some older VWs even pre-pressurized the fuel-system when you opened the drivers door... I know my daughters Gulf did that)

    Also check fuel-pump fuse and relay.
  • shelfershelfer Posts: 4
    Actually figured out how to undo the clips-

    Careful scrutiny and voodoo (with chanting) revealed that the outermost portion of the clip, directly across from the two pin holes was indeed a small button (raised about 1 mm high) which relased the grip on the fitting. An interior panel tool worked well to remove the line.

    After a voltage test on the wiring on the connector to the fuel pump (the two outermost wires) revealed that the voltage was getting to the connector.

    The pump did not hum, so I have taken it out, and then connected it directly to the battery, with the wires attached to the pump itself.

    Chanting and more voodoo did not bring it back to life.

    Thus, a new fuel pum, with gauge float and rheostat has been ordered and should arrive in a day or so.

    I will certainly post if this was indeed the culprit when it it returned to life, as I hate diagnostic threads without conclusions and eventual success.

  • shelfershelfer Posts: 4
    OK. It was indeed the fuel pump. However, for 2004, there are appapently 2 diffent size flanges on teh top of the fuel pimp where it goes into the tank. One measures about 5 inches across in diameter, the other is 5.5 in diameter.

    Of course, I ended up getting the wrong size off of an online order, so I disconnected the float and wiring from the new unit as well as the fuel lines and connected them to the old top flange.

    Cost of new pump was $80 on line, much better than via a parts house around here where pirices ranged from $218 - $308.

    Reinstalled it and away we went (of course I tested it for hum prior to putting it in the tank - older unit had no hum at all, see earlier post).

    Car has much better acceleration now than it has had for some time, leading me to believe that the fuel flow volume was down or just that the pressure was not coming from the pump as it should have been.

    For those that wish to test the unit in the car also - the outermost wires on the connection plug are the ones that power the fuel pump. You can check for current with the key on at that point (Seeing if the relay is still supplying power.)

    I would also guess that one could bypass the relay in order to run the pump in an emergency situation if the relay was bad.

    I put my findings out here so hopefully they will aid someone else in the future.
  • heyjack1heyjack1 Posts: 1
    My wife washec the car the other day and sprayed off the engine and now is running rough and now the check engine light comes on and flashes for a couple seconds and then stays on and just keeps repeating. Someone please tell me what is wrong. We love this car to death and dont want to get rid of it.
  • shelfershelfer Posts: 4
    You should be able to go to a Kragen, O'Rielly or Autozone and they can pull the code. My guess is that it is an igniter problem. (P03xx) with xx being the cylinder where the igniter is shorted out. The igniter swap is relatively easy just don't force the connector. The part is much cheaper aftermarket than it is at Volkswagen if that is indeed the problem. Let me know if that does the trick!
  • vdudzz84vdudzz84 Posts: 8
    Someone please tell me if air coming out of the oil tank is normal? Guy at Valvoline said it's normal.
  • bpeeblesbpeebles Posts: 4,083
    I have been fixing vehicles for many years.... but I am not sure what you mean by "Oil Tank".... Please be specific.
  • vdudzz84vdudzz84 Posts: 8
    So i have air coming outta my oil valve. When the oil cap is loose it bounces around. I went to Valvoline and they told me it's normal for jetta to do that. It seems kind of odd to me. I work to late in the day to make it to a vw machanic so i have no idea if this is a problem.
  • MrShift@EdmundsMrShift@Edmunds Posts: 43,693
    Oh you mean you have pressure in the crankcase? Yeah, that could be a defective PCV valve or "oil separator" (fancy name for it).
  • vdudzz84vdudzz84 Posts: 8
    I was told that my car doesn't have a pcv valve? This is my first VW so I'm not 100% with it yet
  • vdudzz84vdudzz84 Posts: 8
    Ment the oil valve. Crank case
  • MrShift@EdmundsMrShift@Edmunds Posts: 43,693
    maybe they call it an oil separator.
  • vdudzz84vdudzz84 Posts: 8
    Is there a way to test to see if the oil separator is junk?
  • MrShift@EdmundsMrShift@Edmunds Posts: 43,693
    Let's back up. Tell us the year, model and engine you have, and what your symptoms are.
  • vdudzz84vdudzz84 Posts: 8
    I have a 99 aeg 2.0 vw jetta. I just had a full tune up. When i bought the car it had been sitting for 6 months. Right now my oil light stays blinking. I have a lot of air coming out of the top of the oil valve where the cap is. Loosing the cap and it dances sort of speak. It alsogoes thru oil like crazy. I had an oil change 3 week later it was bone dry. It has 119k on the motor.
  • MrShift@EdmundsMrShift@Edmunds Posts: 43,693
    edited June 2013
    THIS MIGHT BE what you need.

  • bpeeblesbpeebles Posts: 4,083
    Your VW engine does *not* have a "PCV valve" like many American-Named vehicles. Instead, VW uses a simple oil-separator which attempts to keep the oil in the crankcase while allowing air to escape into the intake manifold

    When you loosen the oil-fill cap, you are simply allowing some of the excess pressure to escape so the oil-separator does not have to work so hard.

    Unfortunately, there may not be any way you can replace external parts to fix the problem you describe.

    Your description sure sounds as if you have a SERIOUS mechanical problem with your engine. There is sooooo much blowby past the piston-rings, the oil-separator cannot keep up with the amount of airflow past it.

    The blinking oil-lite is another indicator that the engine is in SERIOUS trouble. This means that the oil-pump cannot build up enough pressure to protect the engine.
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