Chirping Engine

Discussion in 'Mech Tech' started by Little Nellie, Aug 25, 2019.

  1. Little Nellie

    Little Nellie Supporter

    hi, last few drives my 2 litre type 4 has adopted a chirp on acceleration. I think I’ve heard this quite often when air cooled VWs drive past, but I’m not sure it used to do it this much.

    It’s not a fan belt as start up or Rev in neutral does not produce the noise.

    So it’s a pulsing bird like chirp. Like a fan belt, but not s shriek, but pulsing. I think this may be quite normal, but any ideas?

    Ta
     
  2. What sort of carbs do you have?
     
    Rich83 likes this.
  3. Exhaust or cylinder to head leakage would be my tuppence worth ...

    :hattip:
     
  4. Little Nellie

    Little Nellie Supporter

    I have twin Weber ict 34s
     
  5. MorkC68

    MorkC68 Administrator

    Google type 4 distributor chirping / also search on here for it and on the samba. It’s a fairly common issue with type 4 motors

    I think Rickyroo has that issue and wrote up how to cure it.
     
  6. ^this, possibly. Distributors can chirrup if they’re running out of lube.
     
    MorkC68 likes this.
  7. Hmm , Dells are known to chirp.
     
    Dubs and MorkC68 like this.
  8. I’m with Lasty on cylinder to head leakage. Only because mine did it when I first bought it.
     
    Lasty likes this.
  9. Little Nellie

    Little Nellie Supporter

    Ok, I hope not. Is this a problem that needs urgently fixing? Gasket or re tightening of boots?
     
  10. Little Nellie

    Little Nellie Supporter

    Cheers I’ll check this out tomorrow when I’m sober enough to take it in!
     
    MorkC68 likes this.
  11. davidoft

    davidoft Sponsor

  12. MorkC68

    MorkC68 Administrator

    :lol: I know the feeling :eek:
     
  13. Little Nellie

    Little Nellie Supporter

    Bolts!
     
  14. Nuts!
     
  15. Little Nellie

    Little Nellie Supporter

    Couldn’t have put it better my self!
     
    snotty likes this.
  16. mikedjames

    mikedjames Supporter

    With old Beetles it could simply be the exhaust, or some aftermarket big carburettors would also chirp. But that would be a permanent effect.


    Just get out a metre or so of hose, hold one end near your ear and then poke around the engine near the heads with the other end and see if you can hear a sharp crackling noise with the engine idling. That is some kind of exhaust leak.

    If its a cylinder head leak then at the least do a compression test to see if there is leaking followed by checking the torque on the cylinder head nuts on the studs.
    Also generally look for missing nuts on exhaust studs or completely missing studs..

    If its the cylinder head to cylinder joint that is leaking then these can get worse as the metal gradually wears away with the hot gas. You may have to remove the cylinder head, clean up and replace bits, like any copper gaskets.. fitted by VW but turned out to double the available space for leaks rather than seal better.

    If your engine was fairly clean there will also be visible black marks from exhaust leaks on nearby metal.
    If its an oily mess.. no way can you see.
     
  17. Little Nellie

    Little Nellie Supporter

    Ta, nice check list!
     
  18. Little Nellie

    Little Nellie Supporter

    Well pretty much bang on with your diagnosis, local expert did an engine autopsy: wrecked heads, one in particular and barrels and pistons too shot to repair. So new top end needed. Gone for all new components and supposedly German. Bit of a bummer but looking forward to a decent engine, and hopefully not being stuck in lorry Convoys.

    Get her back next week.
     
    mikedjames, F_Pantos and Gingerbus like this.

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