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916 And Now I Have A New Problem...

Discussion in '748 / 916 / 996 / 998' started by John Ralston, Feb 22, 2020.

  1. Well, It was a day of highs and lows - I got the 916/996 fuel lines correctly inserted, the "new" 996 fired right up and - dancing! Revved cleanly and then shut down. Finished putting all the remaining bits in order and took her out for a drive, seemed to run very nicely, although I heard a whistle on acceleration that I didn't recall from it's earlier 916 motor (?). Made a few laps of the neighborhood with no issues, put her back on the lift to look everything over and MF!! the sight glass was not clear anymore, had a film on it!!! I've seen this shite before...
    I think that the head gasket might be leaking some coolant into the system. When I reassembled the head after a valve rocker replacement and set up with a new head gasket from a well know Ducati parts supplier here in the states, I immediately noticed it was not like the original 996 head gasket, it was two very thin sheets of metal riveted together on the tabs that stuck outside the head. I don't recall if there were any other O-rings sealing any of the water galleys, but if there were I didn't replace anything since only the gaskets came with the head gasket kit. Everything was torqued to spec and put back together. Sigh...
    So, any things to check and/or tighten before I dive back into removing everything again (arrgg!), pity or stories of encouragement, etc. would be heartily accepted. Also, any pointers as to what I can do when I do open it up and reassemble that will insure that this doesn't happen again would also be greatly appreciated!

    Thanks folks,

  2. Dunno if this is relevant or not: On my Monster, in this kind of weather when it is not terrible hot, the sight glass would always be quite gloomy and they was what looked like an emulsified oil on the sight glass. Nothing wrong with the bike at all. When we got to the summer with nice, warm weather the site glass would be black when the engine was running and clear with just showing the oil level when left for a while to allow the oil to settle down.
    • Agree Agree x 1
  3. Would a pressure test of the cooling system not highlight a leaky head gasket before you head into major surgery again ?
  4. When I used to do an oil change on my mates 996s this would happen nothing was wrong just condensation on the inside of the sight glass , so check there before Pulling it apart ! Good luck
    • Agree Agree x 2
  5. Take it for a longer ride to get the oil good and hot. This should drive the moisture out
    • Agree Agree x 3
  6. It would take a ride of over 20 minutes to get to operating temperature, starting up and stopping a few minutes later will result in condensation.
  7. As said above, it’s more likely than not moisture in the oil. Ride it until it comes up to the temperature where the fan(s) kick in, then ride it some more. It should clear.

    If it is the head gasket that’s leaking, or anywhere, where oil & water can mix, not only will you have a cloudy sight glass but you’ll have an emulsion forming in the coolant tank so check there as well. If the coolant is clear and as it should be then it’s just moisture in the engine oil which will, with heat, be driven out. No need to strip the engine again IMHO
    • Agree Agree x 2
  8. Did you fit the head gaskets on the right way around? They’ll go on one of two ways. Only one is correct.
    • Useful Useful x 1
  9. I worked on an engine that a so called Ducati expert had rebuilt. He had reversed the head gaskets, with the result that the cylinder heads filled up with oil, and the oil and water systems mixed. Great fun...
    • Like Like x 1
  10. Yep. Seen a few over the years. Not the best of ideas
  11. Ok! I wish I looked at this thread before I got up and starting pulling parts!
    Well actually, I mainly drained the fluids, which was probably worthwhile, since there wasn't really any significant evidence or fluid swapping - the oil wasn't perfectly clear, a slightly opaque, but the coolant had no evidence of oil. I'm gonna pull the plugs and take a look inside (cheap Chinese endoscope!) to see if there's any evidence of fluid and if it looks Ok, I'll fill everything back up and take it out for a longer run as suggested (should have suppressed my initial despair and done that any way).

    As far as installing the gaskets upside down, I saw that the manual said to look for ALTO and put that facing the head, I don't recall the gasket I got having any such wording, I did make sure the holes were correctly aligned with the galleys (five on one side three on the other) and the same side was facing up for both cylinders, but whether right side up or upside down I'm not sure. What would be the result of that? could it cause some fluid leakage?

    Thanks again ya'll for all the great advice and help. I'll let you know how it looks.

    • Like Like x 2
  12. One last question, if I did put the head gaskets in upside down (its starting to look like that might be the case), do I need to replace them or can I just turn them over at this point?

  13. I wouldn't ever re-use a head gasket. If you're going to all the trouble of removing the heads, then fit a new one. They've been clamped and although only for a short time, a heat cycle.
    • Agree Agree x 4
  14. Thanks you sir, that's what I was figuring, just wanted to confirm. I know I'm on the other side of the ocean, but does anyone have a recommened vendor for these things?
  15. @nelly !
  16. I'd use OEM. You can still get them, albeit the later thinner type. If you're engine uses the early "thicker" type, you need to swap out the base gasket for a thicker one to compensate so you maintain the squish. Your dealer should be able to supply. They are now tagged as "ST4" gaskets.
    • Useful Useful x 2

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