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VT V6 , VERY rough noisy idle, won't run/rev

Discussion in 'VT - VX Holden Commodore (1997 - 2002)' started by sticksicks, Dec 15, 2018.

  1. sticksicks

    sticksicks Member

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    Hi All. Great site here!
    I've searched for info on my problem here and not found much useful, hence this post:
    I've a Series 1 VT V6, 300K kms, auto, well maintained and serviced. Driven spiritedly :)
    The other day a twat ran me off the freeway into the middle stop lane. I had to floor it to get back to the speed limit on a blind 100kmh corner.
    Engine may have revved to/over 4,000 breifly, oil is not low.
    After this it drove fine and stopped and started as normal.
    Later in the day it stopped driving fine and idles very very badly and won't rev. There is a 'tinking' noise in the top of the motor.
    I've recently done the Crank Angle Sensor and the coils and fuel systems, plugs and leads are tested and fine.
    I did drive a few weeks with a dodgey spark lead on Number 4........:(
    My mechanic has tested the compression on all cylinders and all are good except Number 4, which has ZERO compression.
    Before I call the wrecker, is there anything simple I've missed, or is it likely as fecked as it sounds?
     
  2. commodore665

    commodore665 expat Saffa

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    The lead and plug on cylinder 4 might be knackered , or the injector on 4 is cactus too
     
  3. sticksicks

    sticksicks Member

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    Leads plugs and injectors are all fine, as stated above :)
     
  4. Tree cutter

    Tree cutter Tree cutter

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    Might be a broken valve spring. Take the rocker cover off and have a look
     
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  5. BowTie

    BowTie Active Member

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    Or stuck lifter.
     
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  6. sticksicks

    sticksicks Member

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    Thanks.
    And when it does 'run/idle/cough/fart/snort' it doesn't blow any black smoke like it would with a fecked DFI module or faulty MAF.
     
  7. sticksicks

    sticksicks Member

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    A mechanic did pull off the harmonic balancer very recently, to replace the CAS behind it.
    Is there anything that could have been damaged by this, that would lead to say, slippage in the timing chain systems down the track.
    Seriously, it runs like a slipped chain has put out all the timing.....in which case my motor is well and truly screwed.....but then, so is the mechanic :/
     
  8. gohrdrgomad

    gohrdrgomad Active Member

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    lt certainly could not drive fine on 5 cylinders.
     
  9. sticksicks

    sticksicks Member

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    "Might be a broken valve spring. Take the rocker cover off and have a look"
    Great suggestion. Done. 1 x broken valve spring and damaged retainer and 2 x collets found !
    Pics to follow....
     
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  10. sticksicks

    sticksicks Member

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    20181217_200750[1].jpg
    Yups.
     

    Attached Files:

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  11. BowTie

    BowTie Active Member

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    Good time to turn the engine over by hand and make sure lifters aren't sticking too. Pull all the rockers while your there and inspect and clean pushrods.
     
  12. sticksicks

    sticksicks Member

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    Excellent suggestion.
    The replacement spring is already fitted, thanks to all the other car nerds out there who make How To videos for youtube-nauts like me :confused::D
     
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  13. wildfiremaint

    wildfiremaint Active Member

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    Hi, I’m curious to know did you have to remove the head to replace the valve spring ?
    Cheers.
     
  14. sticksicks

    sticksicks Member

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    Short answer : No.
     
  15. losh1971

    losh1971 Well-Known Member

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    You can used compressed air to hold the valves in place or you can use thin rope. I like the rope method, even though I have never done it. Which way did you choose?
     
  16. wildfiremaint

    wildfiremaint Active Member

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    Hi Losh,
    Thanks I just wanted to know in case I need to do
    that in the future. I like gathering good tips. So I guess you remove plug, rotate engine to lower the piston so that you
    can stuff the rope into the cylinder then raise the piston
    and the rope will hold the valves up ......
    Cheers.
     
  17. sticksicks

    sticksicks Member

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    SHORT ANSWER: Yes, I used the cord into head method.
    I rotated the crank until the piston was just down past the spark plug hole then stuffed it in.
    LONG ANSWER:
    - Clean your engine bay around the area where you'll be working, and lay down a white sheet or the like under the engine
    to make it easy to see things you drop, such as collets......
    - Disconnect battery at negative terminal.
    - Disconnect spark leads, AFTER numbering them on their relative coil packs and cylinders;
    (you will find odd numbered cylinders go 1, 3, 5 front to back on the kerb side and
    cylinders 2, 4, 6, front to back on drivers side)
    - Remove all spark plugs, to make engine easier to turn over by 'hand', by a socket and drive on the harmonic balancer nut.
    - Remove relative rocker cover, taking care not to dislodge dirt and crap into rocker assemblies underneath.

    I had a busted intake spring on number 4 cylinder ((number 6 was the dodgey lead I mentioned earlier. Phew!))
    I found the two wee collet locks and the retainer sitting where they fell and the spring appears to be in two pieces only.
    The valve, in these motors, doesn't fall into the motor as such, there's always a bit sticking out the top of the head.
    But, to keep the valve all the way open/up during reinstall of spring and retainer components, I used the 'stuff-2.5-meters-
    of-clean-cord-into-the-head-via-the-spark-plug-hole' method. Then I gently turned the motor until I felt it resist against the cord.
    This keeps the valve all the way closed and thus it's stem all the way up and is wayyyy easier to refit the spring and retainers on the end of said valve stem.
    I then rotated engine to check the lifter was still working, which it seemed to be.
    Car still won't run..................
     
  18. gohrdrgomad

    gohrdrgomad Active Member

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    How can you be certain the valve will seat, giving a solid comp. It could need lapping or replaced also. Seems to be a hold your balls application and hope for the best. Unless you have applied air to the cylinder. For eg. The valve may have been bouncing on top of the piston...
     
  19. BowTie

    BowTie Active Member

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    Compression test to confirm?
     
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  20. sticksicks

    sticksicks Member

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    You're basically right.
    But I haven't done a comp test....because if the head comes off it all get s too expensive :(

    The mechanic I had the car at for initial diagnoses, said all other cylinders had good compression, but none on number 4.
    The car had 'run badly' , at IDLE, for a total of two to three minutes, including roadside assist diagnoses, and not say, at 100kph on the freeway.
    And so, when I replaced the #4 intake spring, I also pulled out the pushrod and it had suffered NO damage, so I can assume the lifter is also not externally damaged, although there's no saying if it is fecked internally. The spark plug from number 4 is also fine, not damaged.
    So, to summarise:
    Car will NOT start, but:
    Car has fuel, fuel pump, fuel injection, good spark, good coils, NO fault codes whatsoever, a new CAS, a good battery, no water in oil ( although a little in water, as per normal)
    and an engine with dodgey compression on ONE cylinder but it still won't even cough, when I turn it over.
    In fact since being to the mechanic, the starter sounds weak or like it's trying too hard to turn the engine over.
    Perhaps it's on the way to being seized, or all the main bearings are spun.....?
    It could be the DFI, the MAF, the IAC, the Cam Angle Sensor, the Oil Pressure Switch/Sender, the O2 sensors, the this the that.....
    I might try a fuel filter, but really, I've already spent nearly $800 of my time and money on a car that still doesn't run and was barely worth $1500 before it broke. I think the writing is on the bin for this VT......
     

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