Technical Ever since I've changed the thermostat...

[nunesaf]

Hi All
Finally I have some new. I've found out that I had a leak in the thermostat. The hose was not sealing and it was leaking slowly. Therefore not only it was losing coolant but it was allowing air to ingress into the system!

Associated to this constant source of air into the system I was also suspecting an air lock due to the high temperature. The car had 100 C degrees temp in normal driving, leaving the gauge substantially above middle. A bit worrying. Furthermore the fan was kicking in at 110 C degrees. All very worrying for me. Which I thought it was due to the airlock.

So I've then found out the thermostat was calibrated to open at 87 C degrees. I've changed the thermostat core to a 82 C degrees rate and now the gauge falls perfectly right in the middle in the 90 C degrees and the fan kicks in at 100 C degrees.

Maybe the Uno is meant to run much hotter - as I remember my family Uno 45S Evolution (Carb) but then this 1.0 i.e. gauge doesn't give a reassuring reading to the driver. I'll leave this core in there though.

Thank you all for your technical knowledge, support and encouragement . Now I can resume my project plan and continue working on this little great car. It drives so well! I am in love with it again <3.

Cheers

 

[Louie Bee]

top news!!

Did you give the kiss of life?

 

[nunesaf]

Thanks

Actually no I did not! The method I've found out as more efficient was the following:
1) Put coolant up to the min level only
2) With the engine running then, disconnected the top hose of the heater matrix and let it trickle until no more bubble were coming out
3) Either
a) go out for a spin with no cap or
b) to rev the engine every 30 secs or so for 3-5 secs. Everytime you rev, the water is pumped through the system, getting rid of the air.

This procedure is actually recommended in the Punto Service Manual. Some engines don't also have the rear bleed screw (next to the heater matrix) and 3b) is the official way to bleed the system.