75 TS overheating

[GTVeloce]

Hi all

I thought I would do a routine coolant replacement job last night but it hasn't quite worked out as I had hoped. I dropped the old coolant and gave the overflow tank a good clean then refilled. I had an air pocket that limited the amount of coolant that went in but I managed to get that out (at least I believe so) and added approximately the same amount as I took out.

Started her up and the coolant light came on on the ARC (my ARC works flawlessly so I actually pay attention to it). Also, as I drove the car got up to temperature as it should but continued to climb until about 100. I have never had the temp that high before. The fan never lets it get past 90. It has happened this morning as well. When I got to work today I tested a few things;
a) the radiator was cold
b) the make-up tank fluid was cold (but was pressurised)
c) the fan didn't kick in

So, I'm thinking, could it be an airpocket still? How is the best way to bleed a TS? Could it be the thermostat not be opening? That would explain why no hot coolant is getting to the radiator or make-up tank and also why no fan action. Lastly, could the water pump have done it's dash? Any way to test this? The belt is still operating...

Thoughts?

Thanks
Julian

[B_Conolly]

Hi Julian,

If the hose on the radiator side of the thermostat is cold its most likely stuck closed and the system isnt bleeding air correctly.

Remove the thermostat and drop it in some boiling water and it should open (producing a large gap) within a couple of minutes.

This will also eliminate the pump.

All the best
Bret

[GTVeloce]

Thanks for the tip Bret. I will whip the thermostat and test it. I just tried bleeding the air of it with simple measures like disconnecting hoses and running the engine briefly but with no success.

Choderboy - When I first dumped the coolant I didn't but then I remembered and whilst the system was open I opened the heater tap and more fluid came out.

Thanks
Julian

[GTVeloce]

Well, the issue is resolved but not entirely satisfactorily. I changed the water pump last night as changing the thermostat did nothing. The pump was on its way out as the bearings were getting pretty bad but it should still have been operating. Anyway, I swapped it over, filled her up carefully (took a lot of care and effort to get all the air out) and then ran her. She ran so much better. Quieter, smoother (not sure why?!? maybe I'm just wishing it!) and sat just below 80C at all times.

The light was still on however on the ARC panel. After discussions with an expert I realised why. When I had been carefully cleaning the make-up tank I had cleaned all the magnetic strip off the coolant level sensor!

Anyway, the upshot is I'm still a goer for le tour de nord-est this weekend!