Losing water… but why?
Posted: Mon Jun 30, 2025 12:33 pm
Afternoon all,
Just as a disclaimer, I’m running an FB with original everything under the bonnet and I have a query about my radiator and what’s going on. Note that I’ve had my radiator serviced and flushed only recently and it’s got a new 7lb cap.
I went for a 50km drive where 95% was cruising at 100kmh give or take. I pulled into a carpark and noticed a muddy drip for the last 5m and a sizeable puddle directly under the radiator — all of which came out of the rubber overflow tube.
I decided to close the bonnet and carry on shopping, and worry about it upon return when the engine was cooler.
I threw in no more than half a litre of spring water that I had on me which got to about a couple of mm over the fins.
Because I had a few things to do, I kept driving and parking — checking if any drips showed up on the panel below the tube and if anything, it wasn’t more than half a teaspoon.
At my last stop, I visited a friend and he insisted I put a bit more water in and that wound up being a litre and I’d say that sat about 20mm over the fins. I checked the dipstick and there was no trace of coolant / water too.
After that, I got stuck in crazy night traffic — Brisbane can throw up unusual things on weekends — and eventually I wound up on the freeway home with 30km of constant 100kmh driving.
I pop the bonnet as soon as I got home and visually, it didn’t lose a drop of water. Not even so much as a dry stain below the tube.
I just popped the radiator cap open and the level looks exactly the same as when my mate topped it up.
What I’d like to know is, what happened when it decided to spit out so much coolant?
Apologies if this seems like a silly query but I’m relatively new to the eccentricities of grey motor Holdens, but I’m keen to learn as much as I enjoy driving them.
Thanks
Donnie
Just as a disclaimer, I’m running an FB with original everything under the bonnet and I have a query about my radiator and what’s going on. Note that I’ve had my radiator serviced and flushed only recently and it’s got a new 7lb cap.
I went for a 50km drive where 95% was cruising at 100kmh give or take. I pulled into a carpark and noticed a muddy drip for the last 5m and a sizeable puddle directly under the radiator — all of which came out of the rubber overflow tube.
I decided to close the bonnet and carry on shopping, and worry about it upon return when the engine was cooler.
I threw in no more than half a litre of spring water that I had on me which got to about a couple of mm over the fins.
Because I had a few things to do, I kept driving and parking — checking if any drips showed up on the panel below the tube and if anything, it wasn’t more than half a teaspoon.
At my last stop, I visited a friend and he insisted I put a bit more water in and that wound up being a litre and I’d say that sat about 20mm over the fins. I checked the dipstick and there was no trace of coolant / water too.
After that, I got stuck in crazy night traffic — Brisbane can throw up unusual things on weekends — and eventually I wound up on the freeway home with 30km of constant 100kmh driving.
I pop the bonnet as soon as I got home and visually, it didn’t lose a drop of water. Not even so much as a dry stain below the tube.
I just popped the radiator cap open and the level looks exactly the same as when my mate topped it up.
What I’d like to know is, what happened when it decided to spit out so much coolant?
Apologies if this seems like a silly query but I’m relatively new to the eccentricities of grey motor Holdens, but I’m keen to learn as much as I enjoy driving them.
Thanks
Donnie