Evening all.

Had a big journey planned for this evening. But my 899 cinq is now over heating.

A couple of weeks a go it had its engine changed as there was a problem with one of the cam shaft followers.

Been running it with water for coolant since just for a shake-down. And it was running good.

So for the big stint tonight i decided to put proper 50/50 coolant in but now its just started over heating on a run of about a mile to the local blockbuster to drop off a dvd.

When i changed the coolant i bled the system as i have many times beforel.
The cooling fan cuts in for 30 or so seconds every now and then but isnt on excessively.

All the pipes and raidator get hot.

The warning light seems to get brighter, is it a thermistor so the resitance decreases with the temperature?

I was thinking maybe the water has corroded it lowering the resistance?

Cheers for the help.

I'd try bleeding it again. Make sure the pressure cap is well on, too.

Just tried bleeding it again. No luck.

Theres a slight hiss coming from the header tank cap which is now making me think that it is actually over heating.

Or could it be that the pressure cap is fubar?

The cap sounds okay. It will release excess pressure at 1.1 Bar (black..) or 1.2 Bar (blue cap) of pressure, to prevent the hoses exploding.

But there's pressure in there that shouldn't be there, so you do have a problem...

Check that the radiator is in good condition and not blocked... the radiator should feel hot from the top to the bottom. If it's cold at the top, hot at the bottom.. it's got air in it.

Check that the thermostat is opening properly (the hoses to the radiator should get hot) If the hoses feel "tight".. you have air in the system.

If you continually bleed the system and always find air in there, then it's new head gasket time. If you're losing coolant but with no leaks.. head gasket again. It's always the head gasket dude...

The water pump may feasibly be knacked though and it's difficult to diagnose that without removing it.. but if everything else looks good, then change that.. maybe it's just not pumping the coolant round quick enough.

Always use antifreeze. It prevents the iron pipes, block, radiator and the head gasket from corroding (for good measure the rust then grinds into the water pump bearings too).


Ralf S.