1600TP engine Hot and Cold

Discussion in 'Mech Tech' started by mgbman, Jan 12, 2018.

  1. Looking to sort my engine out this year.

    Stopped driving the van 6 months ago as the engine started popping and knocking/rattling.

    Engine starts fine, but rattles/tinkles as the revs are increased. It settles to idle when warm, but still pops but the rattle goes away but runs rough.

    Today I have found something new which I would like help with.

    I ran the engine for about 5 minutes until it idled without needing any throttle. I got underneath and found the no 3 and 4 cylinders side rocker cover and heat exchanger very hot and far too hot to touch.

    The no 1 and 2 rocker and heat exchanger, very cool, just about warm and can be gripped easily.

    Heat risers on both sides were too hot to touch, maybe on the no 1 and 2 side a bit cooler.

    No 3 and 4 input manifolds hot, No 1 cold, No 2 warm.

    Is this uneven heat a clue to my engine problems.
     
  2. 10 minutes after switched off engine. no 3 and 4 still hot, cold/barely warm on the other side.
     
  3. Think you are only firing on 3,4,check tappets on 1,2.
     
  4. I`m guessing its single carb ? possibly snapped rocker or dropped valve ..pull the valve covers !!!
     
    1973daisey likes this.
  5. it has a nice refurbed solex 34 pict 3
     
  6. It sounds like its buggered for sure
     
  7. I think you need to start with the basics and gradually work through everything.
    Check the valve clearances
    Check the ignition timing and gap the plugs
    Make sure your choke on the carb works properly and the throttle position is correct
    Look for any signs of exhaust leaks.

    If that doesn't get you to at least fairly smooth running then you need to move on to compression checks and leak down tests
     
  8. Fortunately I am retired so have time to do more tests on the engine. I don't want to give up with it until I've tried to fix it.

    Re looking for exhaust leaks, I thought it was blowing on the 1 and 2 side but the air flow seems to be from the crankcase hanging down breather pipe.

    I was checking that when I noticed the cold side and very hot on the 3 and 4 side.

    Re valve clearances, when I bought it 4 years ago, the 3 and 4 exhaust ones were tight with no clearance and I have checked and adjusted all round regularly since then, but the 1 and 2 closed up again.
     
  9. I meant 1 and 2 were tight, not 3 and 4, the 3 and 4 have always been ok.
     
  10. Check the rubber manifold boots first for any splits.
     
    Dubs and snotty like this.
  11. ^this. Does sound like one side's running hot. Ideally, prob best to pull the engine, whip the heads off & have a good looksee...
     
  12. Try pulling spark plug leads off 1,2 see if engine note changes.
     
    Moons likes this.
  13. mikedjames

    mikedjames Supporter

    From your description the 1 and 2 side is misfiring.
    I would check the rocker arm nuts are tight as well as the inlet manifold to head joint nuts are done up.

    Something like a heck of a lot of air leaking on 1/2 side so no combustion and some air leaking across and making the 3/4 side run barely and run hot and lean.


    My major yellow taxi time was down to a snapped securing clip on the No 2 exhaust valve rocker arm. Sudden loss of power and the backfiring burst the opposite manifold boot so then 3/4 were lean as well. It ran at about 20mph bucking and leaping but I failed to leave the motorway because a slight hill was too much.

    The loose rocker arm happened more recently and that just caused a progressive loss of power over about 5 miles until it would only run on the level.

    By the time I stopped the No3/4 cylinder head was cold . About 30 minutes of fault finding and a quick tightening up with a 13mm spanner and I departed just as the haulage company whose driveway I had parked opened for business.
     
  14. Baysearcher

    Baysearcher [secret moderator]

    Can you put up your registration plate so we can all check your MOT history?

    :D
     
    Moons, davidoft, philntfc and 4 others like this.
  15. May be 1,2 exhaust valves have sunk.
     
    3901mick likes this.
  16. I forgot to mention with the engine idling, the air flow out of the oil filler (cap removed) and the breather hanging down pipe is quite strong. Is this some form of blow by or air leak symptom.
     
  17. 77 Westy

    77 Westy Supporter

    The only way the crankcase can become pressurised is from blow by. Have you done a compression test?
     
    snotty likes this.
  18. Thanks for the helpful responses. Seems I have a lot to check out to get to the bottom of the problem(s).

    Just thinking whats best to start with, ??

    rocker covers off
    remove spark plugs
    set cold valve clearances to spec
    rocker covers back on

    remove king ignition lead
    do compression tests
    write down the psi
    squirt some oil in spark plug holes
    do compression tests
    write down the psi

    rocker covers off
    check out rocker arms and valve springs
    unbolt rocker arms and remove
    pull out push rod tubes

    what next?
     
  19. I would do the easiest first - whip off plug leads one side at a time - then do compression test - then if no joy take off rocker covers and see what's loose/tight
     
    mgbman and snotty like this.
  20. ^this, probably easiest. If you've got contact breakers, just whip the green lead of the coil -ve to kill the ignition.
     

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