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Type iv head problems....I think?

Discussion in 'Bay Tech Clinic' started by Ragerty, Jun 30, 2012.

  1. Ragerty

    Ragerty Member

    Messages:
    92
    Location:
    Wodonga
    Hi,

    Travelling home forom work...pop bang pop. Loss of power...managed to plod home...

    Changed dizzy, condensor, points, checked plugs and clearances.

    Clearances on pot 3 -one of the clearances had opened up by a significant amount...similar to one valve on pot number 1

    Compression test-
    #1- 120psi
    #2- 10psi
    #3- 0psi
    #4- 120psi

    Does it appear valves seats have shifted? Seems odd no compression on pots 2 and 3?

    Any advice?

    Maybe I should sanity check my clearances sgain otherwise looks like I'll have to drop the engine.

    Thanks in advance
     
  2. gazman

    gazman Well-Known Member

    Messages:
    1,890
    Location:
    Perth WA
    Haha sanity check, I need one of those sometimes....
    double check the valve clearances on #2&3, make sure the engine is turned over so the valves are completely closed first. If that doesn't help then its not looking good with readings that low :cry:
     
  3. MickH

    MickH New Member

    Valve seat issues....not uncommon.Remove head,repair or replace.
     
  4. Ragerty

    Ragerty Member

    Messages:
    92
    Location:
    Wodonga
    Cheers guys...dropped the engine today...that's a fiddle job...how do you get that back in...not much room for manoeuvre. Yeah think the seats have popped out...I hope it's not worse...will have the heads off in the morning.
     
  5. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,959
    Location:
    Melbourne Bend of Islands
    Interesting that 2 cylinders are kaput?
     
  6. Ragerty

    Ragerty Member

    Messages:
    92
    Location:
    Wodonga
    Yes I thought that...I tested them 4 times each..rescrewing the compression tester in each time to make sure I had a perfect seal.
     
  7. oldman

    oldman Super Moderator Staff Member

    Messages:
    10,202
    Location:
    Avalon Beach NSW
    Broken valve stem/s ?
     
  8. Ragerty

    Ragerty Member

    Messages:
    92
    Location:
    Wodonga
    I really don't know till I pull the heads off tomoz....fel like doing it now....bit like Xmas wondering what I will unwrap...only I know it's not gonna be good...the thing is I've looked after my engine...not been thrashed or overheated etc, regular oil changes, clearances checked and then pop pop pop. Doh
     
  9. Ragerty

    Ragerty Member

    Messages:
    92
    Location:
    Wodonga
    Ok..took the heads off today but before i get on to that I would like to thank you in advance for your advice...it is appreciated.

    As you can see in pics below of the pistons and heads

    #1 - this gave a reading of 120psi but was very oily inside the head, you can see the oil in the bottom half of the piston with the carbon build up. Woud the valve guide be worn to cause this much oil in the chamber?

    #2 - this gave a reading of 10psi but was very oily inside the head, you can see the oil in the bottom half of the piston with the carbon build up. I can't see exactly what caused the low compression buy a trail of oil can be seen leaking at the bottom of the pots...could the gasket have gone?

    #3 - no reading whne compression tested. Tha valve seat has popped and damaged the top of the head but also clonked the crown of the piston. Could this have damaged the crank....is it worth a check?

    #4 - 120psi - best chamber out of all four.

    12 months ago I had all the valves replaced and the seats recut. New piston and rings was also installed.

    [​IMG]

    [​IMG]


    Your advice is appreciated.

    Cheers
     
  10. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,959
    Location:
    Melbourne Bend of Islands
    Not a good result for 12 months kruising.
     
  11. Kai

    Kai Well-Known Member

    Messages:
    4,782
    Location:
    Sydney, NSW
    Am I correct in saying that the heads don't look that old?
     
  12. Ragerty

    Ragerty Member

    Messages:
    92
    Location:
    Wodonga
    The heads are original vw. I had them cleaned and new valves put in with the seats recut too.
     
  13. gazman

    gazman Well-Known Member

    Messages:
    1,890
    Location:
    Perth WA
    No 2 exhaust valve looks burnt too....
     
  14. VanAime

    VanAime Active Member

    Messages:
    2,343
    Location:
    Primate Gully Vic.
    On cyl no. 2 & 3, you can see where the head has been leaking. Usually terminal as the gap gets bigger as the engine heats. It indicates the head wasn't torqued down properly or in all likelihood the head gasket failed.
     
    Last edited: Jul 2, 2012
  15. Ragerty

    Ragerty Member

    Messages:
    92
    Location:
    Wodonga
    Torque settings were followed by the book but if that is the case then I hold my hand up as I rebuilt it. Doh but if the head gasket went either way...wouldn't the performance affected be noticeable rather than no compression full stop. My bus had been running a treat...I'm having the head vacuum tested. Will see where the issue resides...apart from me. Lol
     
  16. beep

    beep Member

    Messages:
    40
    Location:
    Brisbane
    Hi Ragerty. Sorry to hear about the bad luck. I agree with Alpal that 12 months isn't long enough after all that work. I just went through a similar thing with an engine I bought as a long block (built by an alleged professional) that had lots of things wrong with it. And really wrong.

    Anyway I've never had any luck with reconditioned VW heads so recommend new ones. They're pricey, but great quality. Old ones usually go kind of soft and can't hold their seats even if they're replaced. The new ones are so well machined they don't need head gaskets. And if you fit them yourself you'll save heaps of cash for labour.

    If you're that far into the engine, I would also replace the pistons and cylinders. I just did on mine for about $550 and the new parts are great quality. You'll have to replace number 3 in any case.

    And the trick to getting the engine back in is don't disturb the clutch and remember to take the car out of gear when you try to get it back in (ask me how I know)...

    Good luck.
    c.
     
  17. VanAime

    VanAime Active Member

    Messages:
    2,343
    Location:
    Primate Gully Vic.
    "Torque settings were followed by the book but if that is the case then I hold my hand up as I rebuilt it. Doh but if the head gasket went either way...wouldn't the performance affected be noticeable rather than no compression full stop. My bus had been running a treat...I'm having the head vacuum tested. Will see where the issue resides...apart from me. Lol"

    I've been getting some excellent info from Bob Hayes in the States and he claims the book torque settings aren't enough. This is from one of his info sessions.....

    "[FONT=&quot]Regarding me reworking the heads, I always leave them stock, re new AMC. I don't trust any head for super long life that's had the seats replaced, eventually, one on every motor will come loose, as your friends did. All genuine VW heads came with the seats peened into the head except for the 2 litre. [/FONT] [FONT=&quot]Regarding me reworking the heads, I always leave them stock, re new AMC. I don't trust any head for super long life that's had the seats replaced, eventually, one on every motor will come loose, as your friends did. All genuine VW heads came with the seats peened into the head except for the 2 litre."

    This explains the rest..........

    "The main reason these engines fail is - leakage between the cylinder and the head (see my website under air cooled facts/4 leaks in one). The torque specs in the book are too low, eventually leakage begins here and combustion temps begin to rise due to lean mixture from air being pulled in through here, not being metered by carbs or injection, and the hot lean mixture causes valves and seats to begin to burn and it's all downhill from there."

    Hope that helps and provides some direction.
    [/FONT]


    [FONT=&quot]
    [/FONT]
     
  18. Ragerty

    Ragerty Member

    Messages:
    92
    Location:
    Wodonga
    Wow! Yes that's loads of information to run with...I guess it's back to the basics and re.build from there on but I do appreciate the help and advice from you guys too.

    I must ask if the torque settings are too low....what should they be and would threadlock be useful on the studs. I'll also check out bob Hayes if I can find his web site...onwards and upwards...I'll be back on the road...sometime soon....ish lol
     
  19. VanAime

    VanAime Active Member

    Messages:
    2,343
    Location:
    Primate Gully Vic.
    Just tried to post up some more helpful Bob Hayes tips concerning heads here, but the pics must have been too big or the wrong kind. I don't know all that much about computers.

    Anyway, if you can PM me your email addy, I'll send you the files.

    Bob's website, although not a particularly good lay-out can be found at.............

    http://haysvwrepair.com/2011/03/vw-type-iv-heads/
     
  20. VanAime

    VanAime Active Member

    Messages:
    2,343
    Location:
    Primate Gully Vic.
    Bob's currently building me a set of heads for my 2lt. They'll hit my doorstep via insured post for the princely sum of $1535. That includes seats correctly machined by Bob, new retainers checked for fit and installed and both heads leak tested.

    Good time to buy with the current almost parity of the US to Aussie dollar. With financial contagion spreading throughout the world as a direct result of the European crisis, our high Aussie dollar most probably won't last much longer.

    $1535 from US shop to door may sound a little high, but I'm guessing if you bought a pair of AMC heads in Australia, then paid someone else to do the machining and lapping, testing and sizing of retainers, the labour cost in Aussie dollars might run even higher??
     

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