Volvo AWD S70 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 6/2008 S70 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

Tried PCV repair...now car dies S70

posted by  Rosbif22 on  Thu Oct 28 12:35 CST 2010
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Sat Nov 6 21:11 CST 2010
[RELATED]

Hello all,

I attempted to change out my PCV tubes and all that, and it seemed to go well.

However, now when I try to run the car, it doesn't want to stay on. It runs very roughly and turns itself off quickly.

If I give it a little gas, it hesitates badly, makes a popping noise, and then will rev...
I think I killed the tubing that comes out of the front of the manifold. Is that what's causing my issue? Or some other tube somewhere?

Please help!







  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Tried PCV repair...now car dies S70

    posted by  Rosbif22 on  Fri Oct 29 21:51 CST 2010
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Sat Nov 6 21:11 CST 2010
    [RELATED]

    SOLVED.

    jablackburn was absolutely correct: that stupid bracket, combined with my own stupidity, was apparently leaving enough of a gap to cause vacuum problems.
    Removed the manifold (AGAIN), removed the bracket, put it all back together...no more popping noises!

    Also, it appears that MAF is good after all...the car runs with it plugged in again. The car must have been trying to make corrections to account for the leak to the point where it just turned itself off to "cope."








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Tried PCV repair...now car dies S70

    posted by  jablackburn on  Thu Oct 28 16:30 CST 2010
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Thu Jan 20 10:56 CST 2011
    [RELATED]

    There's air getting in somewhere.

    Look CLOSELY at all turbo/IC pipes. I left two kinda loose, and they blew off as soon as I put my foot down when I felt something didn't feel right. Bam, instant loss of power.

    Did you leave the bracket in place at the bottom right side of the intake manifold where it bolts up? If it gets stuck in between, it will leave a nice air gap there and your engine will be confused. I just remove the bracket entirely.








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Tried PCV repair...now car dies S70

      posted by  Rosbif22 on  Thu Oct 28 18:32 CST 2010
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Sat Nov 6 21:11 CST 2010
      [RELATED]

      Replaced the vacuum tubing that comes out of the front of the manifold...didn't change anything.

      I did leave that bracket in there; I'll try to pull it out tomorrow and retighten everything. My car never had power from the moment I tried to restart it after I changed everything...it's just been turning itself off immediately unless I force it by giving it gas. And, of course, those popping noises are quite worrisome.

      Any other suggestions, anybody? I'm all ears.








      •   REPLY TO THIS MESSAGE    PRINT   SAVE 

        Tried PCV repair...now car dies S70

        posted by  tmannian on  Fri Oct 29 06:52 CST 2010
        Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
        last visit: Sat Sep 20 10:31 CST 2014
        [RELATED]

        I agree with massive air leak.. Might be a bad connection in the intake manifold (either loose or bad gasket placement). Check intake air hose for cracks... This is one where you should be able to detect with propane... Use a torch with just gas on (NO FLAME!!!!) and run it along the air lines, when the engine picks up speed you've found your area of leakage...
        --
        If you're not driving it "like its stolen," are you really driving?








        •   REPLY TO THIS MESSAGE    PRINT   SAVE 

          Tried PCV repair...now car dies S70

          posted by  Rosbif22 on  Fri Oct 29 10:02 CST 2010
          Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
          last visit: Sat Nov 6 21:11 CST 2010
          [RELATED]

          Bad gasket placement? I threaded the gasket onto the lower four bolts, put the manifold on top of it, threaded the top three bolts, tightened them all down. Could the gasket somehow still be out of place??

          Also, the car stalling has been solved, I think. I pulled the MAF connector on a hunch, and sure enough, the car stays on just fine (albeit it runs like crap). Guess that means it's time for a new MAF sensor. Damn.

          That popping though...disconcerting. Is that indicative of an air leak? When it happens, the revs drop a bit or raise a bit.

          I'm so confused, I could swear I put everything back together carefully. I actually used your tutorial, jablackburn...great job on it, it's very good :)








          •   REPLY TO THIS MESSAGE    PRINT   SAVE 

            Tried PCV repair...now car dies S70

            posted by  jablackburn on  Fri Oct 29 10:31 CST 2010
            Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
            last visit: Thu Jan 20 10:56 CST 2011
            [RELATED]

            Thanks =)

            I still suspect you've got an air leak. It should run fairly well without the MAF sensor, as it is using its "best guess" for a new engine. The fact that it's running, but still like crap points out to me that there's still unwanted air entering the engine - it is better now that the MAF sensor ISNT correcting for it with a lower value.

            Unbolt the manifold and pull the bracket out. Or try the carb cleaner trick the last guy mentioned around the gasket seal and see if you get anything else.

            The popping noise you are getting is a backfire - if the engine's stumbling due to either the bad MAF sensor or an air leak somewhere, it's confused and choking on too much gas. Kinda like an old out of tune go-kart engine if you suddenly floor the throttle and let off again quickly.

            If you're still having trouble with it tonight, send me a PM from Matthews and I'll send you my phone number. I've done about 3 of these and should be able to help you, but I just don't like to put my number out there on the internet - I get enough calls from telemarketers as it is...








            •   REPLY TO THIS MESSAGE    PRINT   SAVE 

              Tried PCV repair...now car dies S70

              posted by  Rosbif22 on  Fri Oct 29 11:09 CST 2010
              Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
              last visit: Sat Nov 6 21:11 CST 2010
              [RELATED]

              I very much appreciate the offer and will take you up on it if I need to...which I'm hoping I won't, as the carb cleaner trick reveals that the manifold is probably a bit too low, especially on the right hand. It revs quite nicely when you spray it there.

              Now, I'm assuming that I can just undo the 7 bolts, have my wife assist in pulling up the manifold a bit, and retightening them. Am I correct in this, or is there something that I'm missing? Do I need to undo the bottom 12mm bolts?







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.