Alfa Romeo Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
I have a 2015 QV MiTo with 19,000 km. The outlet nozzle of the plastic coolant expansion tank failed. Heat around the nozzle has left it a discolored brown and the nozzle itself was cooked off.

I never experienced abnormal temperatures, so I assume the plastic material of the tank at the outlet was defective.

I estimate that I have lost about half the coolant or more, maybe a gallon. I have purchased 2 gallons of 50/50 coolant in case the loss was greater.

The radiator is a mystery to me. The engine bay is so crowded with components that I can’t see it clearly.

1. Does it have a radiator cap? Where is it?
2. Where is the bleed screw and what do I have to do to get access?
3. Do I need to worry about the bleed screw, or can I simply slowly add the coolant mixture in stages as I heat the engine without pressurizing (expansion tank cap off) the system until the level normalizes? Then, keep a close eye on it and top up over the course of a few days?

Gracias for the help.
 

·
Registered
Joined
·
9,313 Posts
1. Does it have a radiator cap? Where is it?

It's the cap on the expansion tank .. it's blue on our MiTo.

2. Where is the bleed screw and what do I have to do to get access?

May not be one (never had to look to be honest!) I think the rad is mounted too far forward anyway.

3. Do I need to worry about the bleed screw, or can I simply slowly add the coolant mixture in stages as I heat the engine without pressurizing (expansion tank cap off) the system until the level normalizes? Then, keep a close eye on it and top up over the course of a few days?

Basically yes.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #3 (Edited)
Thanks to Gazza 82 for your comments.

I couldn’t find the bleed screw, but it turns out I didn’t need to.

I filled the expansion tank with the motor running and the cap off.

It burped and the level receded. I filled it and it receded more. I then filled it again, put the cap on and took it for a short drive. I carried extra coolant with me and carefully monitored the engine temp. I topped up several times in the course of two days and added a total of 5 liters of coolant since I installed the new tank. My owner’s manual says the capacity is 6 liters, so I had lost most of my coolant with the failure. Yet, I appear to have gotten by without the need to bleed. Temperature and the level of coolant now seems normal.


As a footnote to my earlier question about the presence of a radiator cap. I have discovered it has none. The cap on the expansion tank acts as the sole access to fill the radiator. Then, my misfortune in having a dead and unrevivable battery required that I remove it and in the process I discovered where the second outlet from the expansion tank leads. It returns to the block near the radiator hose return. Just for the record.

The outlet at the top of the expansion tank goes into two hoses. It is really hot water under pressure. One hose disappears into the darkness of the lower engine bay. I assume it finds its way to the radiator (actually the block, as it turns out). The other hose goes to the turbo charger. There I find what may be a bleed screw (two, in fact). Since, my problem was resolved, I let it be. But I pass this on for whatever value it may be in shedding light on the mysteries of the Mito’s coolant system.

Cheers,
 
1 - 3 of 3 Posts
Top