Overheating 999 ?

[CarsOrBikes]

Ghost actually mentioned the w/p as a possibility, but el toro first made a sound point, in that for 6 quid? a cap 'could' be the cause. It does vent at a set pressure, and if faulty, can explain what yours is doing. If nothing changes, it could still be an air lock, things need checking like equal temp hoses, to see if t/stat gets opened? Confirm w/p actually 'is', hoses may 'move' (expand/contract) a little as revs raised a bit, or with cap off the level can be seen to 'swirl' or appear to drop, then raise slightly at idle again. Air locks can be a pig to get out, sometimes it helps to let it spew out what it wants, (don't wait forever) and top it up with boiling water again (slowly), to keep the t/stat open (or even open it in the first place). You should be able to get away with running the bike for a while with the cap off to get an idea of how quikly it tries to expel. I may settle if you let it throw 'some' out, and see if level suddenly drops further than you think it should for what just came out (if you get what i mean) then top up slowly with v/hot water, see if it settles. If you get a longer interval than at first, you may have released the lock, wait for a bit longer, if you think something has changed, get the cap on and run it further to confirm.

Hard to explain, I had a pig of an air lock after experiencing exactly what you are but on an RSV 'R' 04 that i bought as a cat 'c', the salvage dealer had fitted a coolant hose, and topped it up correctly with coolant etc. and even run it for 'a period'. It was only after i did 'my bit' that i found the problem. I was initially worried there was more to that bike, but in fact just patience and 2 - 3 goes at letting it throw stuff out, finally got it. Coolant circuits dont differ 'that' much in the basic operating principles, hence my suggestions, my 2p if you like.
I Don't know how much you want to try, but it can be quite gratifying to find out what it 'really' was.

Cap first if 6 quid?

Kettle on twice, 1 for tea, 1 for standby to top up as required (bike not tea) :-)

[mw999]

Thanks again for the info.
Took the bike back to Ducati dealer today. Explained the history and used some of all your possible explanations - must have sounded quite knowledgable!!! After an hour of checking they now think it's the head gasket that's gone so I've had to leave it with them. Gutted.
Looks like you were right "carsorbike" - although I'd rather it was just the cap!!!.
I'll post the final outcome in case it helps someone else later on.
Thanks again

[safetyfish]

They think what? Head gasket?

On what do they base this assumption?
Is there water in the oil sump? Is there water leaking from an area on the cylinders or on the engine?

Correct me if I am wrong but you saw the water coming from the radiator cap - correct?

SF

[CarsOrBikes]

safetyfish, it could be the h/g as the gasket may have failed sealing the compression chamber to the coolant circuit, this would pressurise the system.

I still have reservations about this though. You can do a 'block' test on a car that will tell you if carbon monoxide is in the coolant, so the dye changes colour if it is. May be hard to do on a bike. The seal can be letting go at a high temp too, it is hard to tell. It could be a faulty t/stat even.

Like the others suggested, cheapest first could be the way to go.

Are Ducati paying for the h/g work?

If not maybe worth a complaint, esp if the bike isn't that old or with high mileage?

How much faith would I have in a dealer that says my h/g is gone, when they already told me the symptom is normal? Not Much! The bike would be in somewhere else.

This would reinforce a complaint to Ducati.

Whatever happens........... good luck, it will come out in the wash so to speak.

[theoldbuzzard]

Originally Posted by mw999

Checked radiator and it was full to the brim. Checked level was mid way between upper and lower levels in expansion tank and left engine ticking over.....Left fan kicked in at about 103, right fan at about 105. They didn't seem particularly effective and didn't appear to be pulling much air through but both were on. Temp continued to rise but not quite as fast.
After about a minute the expansion tank relieved at 107. Temp then dropped to 103 then rose again....and tank relieved again. Temp seemed to stabilise at 107 / 108. I increased revs a little to just above 2000 and saw temp drop to 103 virtually immediately.
Left it to tick over again and it dropped another small amount of coolant onto my drive!!!. Got a bit nervous then because there had been quite a lot of water dropped - so switched engine off. Fans stayed on till about 101. Waited for it to cool then found I had to put in 250 millilitres of water just to get it back to the minimum liquid level.

Everything you said above is normal until you had to top up again. I have my bike serviced by the same dealer (I think) and have had the same problem with water being dumped after getting quite hot, I think that they always over fill when they service.

The temperatures that you note are perfectly normal and it is also normal for the temp' to drop when you pick up the rev's. There is an optimum speed for the coolant to pass through the rad', too slow and the temp' rises, speed it up a little and the temp' reduces but then will rise again as the coolant passes through the rad' too fast to be cooled. I often do this in traffic, allow the engine to tick over but then, when the temp' gets to around 110, pick the rev's up to around 2000 until the temp' drops to 105 or so.

The problem that you describe does suggest the rad' cap being to blame. The system is "overpressurising", this could mean that it is overpressurising due to the headgasket failing but it could just as easily mean that the pressure is normal but the rad' cap is weak and "tripping out" at too low a pressure.

Sorry that this has been a bit late for you to sort it out yourself but, on a different thread, I have given Riders a vote of confidence and hope that you get the same good service that I did.

[mw999]

Well....Looks like it's sorted.
After a lengthy check the dealer still thought it was a head gasket so replaced them. Apparently this is not a common fault - the only time the mechanic has seen this problem, but they said as soon as they opened it up they saw where the gasket had been passing into the cooling system. It had been pressurising the cooling a little and would have increased as the temp rose.
Picked the bike up and let it tick over till hot - no problems.
Had a great run up the coast road - temp didn't rise above 80 even through towns.
Let it idle once I got home. Fans kicked in at 102 and 103 and cooled engine back down to 100 several times.
Hopefully that's it - no more problems. If i do have any more cooling problems I'll bear in mind all your advice in the previous threads - my thanks to you all for your advice and help.
Cheers!!

[safetyfish]

I would never have thought that is the cause of the problem, but still glad your bike is sorted.

Enjoy the ride mate

SF

[CarsOrBikes]

Great, good that the tech saw the leak spot, always reassuring when the defect is visible.

Happy days.

[Ghost]

I think I mentioned it in post 4.!!

[moto748]

Pleased you've got it sorted.

I'll bet a head-gasket ain't cheap, though.