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999 How Hot Is Too Hot?

Discussion in '749 / 999' started by Old rider, Nov 14, 2014.

  1. my 999 runs at a nice steady 70 degrees when ridden free but once I get caught in stop-go traffic, the temperature starts to climb.
    So, how hot is too hot and what to do about it?
     
  2. 1st fan kicks in at about 100 and 2nd kicks in at 105 if I recall so don't worry about a ting
     
  3. Wrong side of 100 if no anti-freeze you are in trouble !!
    Check fluid level.
    In hot summer mine climbed to 108, both fans running
     
  4. As above, they all do that sir. (On my 998 the [dry] clutch gets grumpier as the engine temp goes up, too.)
     
  5. Keep an eye on it. I have the same engine and the constant increasing temp led to a head gasket failing - luckily covered under warranty!
     
    • Like Like x 1
  6. Think there is supposed to be 1c between the two fans I thought it was 101c and 102c . then off at 1c below on both fans .
     
  7. Well that's quite a worry.
    What temperatures were you seeing and how often??

    It seems to me that the radiators are perfectly adequate as long as there is a reasonable airflow but how adequate are the fans?
    I tend to avoid heavy traffic, having been alarmed by watching the temperature climbing, so I don't have much experience of how well the fans cope but they certainly don't bring the temperature back down to the levels I'm used to seeing when not in traffic.
    The system is pressurised, so the coolant won't boil at 100* as it would otherwise and maybe the additives push the boiling point above that of just water as well but I wonder why Ducati set the point at which the fans come in so high - is it because the charging system can't cope too long with the fans running at idle and the battery will start discharging? Maybe we should make sure the headlight is off if the fans are running?
    Are the thermostats really accurate enough to switch on one fan and then the other precisely after just one or maybe two degrees or is it that the two fans have independent thermostats for fail-safe reasons and one just happens to kick in before the other?
     
  8. 102 then 103/4 for 2nd fan on mine. In traffic in sunny weather mine goes up to 108+ fairly fast. The temp starts flashing at 120 meaning danger, I switch off and let cool down at about 112. I shut off at 120 once(in Florence) and it boiled over due to latent heat.
     
  9. Yes, it's the heat-soak bit and at what point to switch off that worries me...
    So the fans don't really cope and keep the temp down. I guess stronger fans might drain the battery at idle but I'd prefer that to a fried engine!
    You'd think a bike designed and made in Italy could cope with temps in Fiorenza
     
    • Agree Agree x 1
  10. You could be right, I did kind of guess
     
  11. Whyever would Ducati have the fans come on sequentially with just a one degree difference but cut off together. It just seems bizarre... The only reason I can fathom is to avoid a sudden load on the charging system but why??
     
  12. The fan cut-in temp can be altered by reflashing the value in the ECU. I've done this for a few forum members.
     
  13. Seems a good idea, maybe it's easier to keep the temp down if the fans cut in earlier...
     
  14. No, was definitely the rising temperature, consequent thermal expansion and thereafter evaporation and expulsion of coolant that caused the head gasket to fail.
    Keep any eye on it!
     
  15. So your Cooling system pressure cap and expansion bottle failed then? I'm sorry but I'm with @Mr.R on this, your h/gasket is under much more stress running than from heat soak expansion.
     
  16. I was with two others and got stuck in the tunnels under brussels , been a crash , we were there for some time just inching forward . My then 999s went up to 120 c at one point . We were rescued by a cop on a motorcycle that got us up a down over ramp with flashing lights and lots of arm waving . Bike dropped down to 80 as soon as we got out and didnt seem to suffer.
     
  17. I too always build/tune 'race' motors to copĂȘ with the heavy Geneva rush hour trafic so I'm sure you know best! I'm also always available on the evening of friday the 25th July 2014 to diagnose the symptoms other people's mechanical failures and second guess the opinions of the local Ducati agents and contravene the laws of thermo-dynamics. I always listen to what 'I've been told' am and in no way a complete bell-end!
     
    • Funny Funny x 1
  18. My 916 will soon see temps of over a 100 degrees if in traffic, other than the hot air blown at me from the fan it doesn't seem to suffer for it...
     
  19. Maybe the 916 fan system is better able to stop temps rising too fast or too far. There's no doubt the 999 rads work beautifully at any reasonable speed, it's the fans' ability to give enough airflow when stopped or just trickling along that is in question, as well as at what point to switch off and let it cool down.
    I did find elsewhere a reference to 999 fans sometimes becoming detached from their spindles, so the motor or motors are whirring away but the fan blades are doing nothing!
    Maybe something worth checking...

    Also, Desmotimes were selling replacement, higher flow metal fan bladesfor the 916 etc, with a single fan but nothing for the twin fan 999
     
  20. I've ridden my 2003 999S in anything up to 30C of heat, including some stop-go through towns. The most I ever saw on the temp gauge was 108C.
    One time there was a complete traffic snarl up and it was impossible to find a way through Chichester - and I know a lot of ways around that town. I completely over-heated and had to pull over ... but it was me that was too hot, the bike coped fine.
     
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