Hi,

It's a Twinair from 2011, with just 32,000 miles on it.

Lots of fan noise the other day, so checked coolant and expansion bottle practically empty.

It took 2 litres to fill, I then drove 25 miles, and the following/this morning, it was empty again, but only took 1 litres to fill.

The belly pan is wet looking under the sump, and the water pump, but the pump's running quiet, and I had my mechanic check it a month ago when he did the oil change.

It's not the expansion bottle, there's no oil/water mix, and it's not the radiator.

There's one hose between the rad and the pump, that I can't reach to check, so it could conceivably be that, but it doesn't look perished from above.

One heater hose looked okay, too, but I haven't given it a proper examination, and I can't see the other.

So, I'm completely stumped.

Any suggestions?

Cheers, Peter.

AndyRKett said:

https://www.fiatforum.com/500/474912-why-you-car-might-dump-its-coolant.html

Click to expand...

That relates to the 1.2 engine.
That particular pipe is well known for rusting out.

The Twinair has a much more complicated cooling system.
It'll send coolant to the turbo and I believe there maybe some sort of heat exchanger on the oil system as well that will have coolant flowing around, so there's far more connections and pipes that the 1.2.

There are a few posts relating to the return pipe from the turbo to expansion tank leaking.
The stub on the tank becomes brittle due to the heat.
https://www.fiatforum.com/500/451727-twinair-coolant-leak-turbo-pipe.html

Other than that you'll probably need it up on a ramp to try an identify where it's coming from.

The broken dibber on the header tank sounds unlikely, judging by the amount of coolant it's leaking.

The main thing is that the leak is coming from below, rather than above (coolant being blown out of the header) since the latter would be more likely to be a gasket problem or something equally mechanical.

My money is on a punctured or fractured radiatore. You'll need to take the bumper off and have a look.

Radiators are not too dear (if you buy from a motor factor rather than a Fiat dealer - a Nissens one is c. £70) - and fairly simple/cheap to fix.


Ralf S.

In the morning when fully cold, look for leaks, then fill to full if required, start the car and allow to run until the cooling fan comes on looking for leaking all the time, that much should be evident? Place a sheet of cardboard underneath?

SOLVED

It was the oil filter housing at the back of the engine, which also has a small oil cooler, and coolant is circulated through it, too.

It's what you screw the oil filter cap into (unsurprisingly)

Part Number 55225515.

It's a puzzle why it cracked, but it's plastic, so you might not want to use a second hand part.

It was a lot of labour to trace this problem, and fix it, as a few things were in the way and needed removing, and space was tight.

It cost me £450 all in. I don't know what the part cost, but second hand ones are about £80, as we speak in 2019.

loserscar said:

SOLVED

It was the oil filter housing at the back of the engine, which also has a small oil cooler, and coolant is circulated through it, too.

It's what you screw the oil filter cap into (unsurprisingly)

Part Number 55225515.

It's a puzzle why it cracked, but it's plastic, so you might .

Click to expand...

Over tightened filter/cap?