Car thread - Vauxhall Mokka - Coolant Leak

[Beancounter]

2015 Vauxhall Mokka 1.4. Girlfriend was driving the car last Sunday when the temperature light came on. She managed to pull over about a mile later on a garage forecourt, popped the bonnet and saw that the coolant was empty, well the expansion tank, you can't actually get to the radiator. She let the engine cool down before topping up but any water she topped up with just ran straight back out again.

No idea where the leak actually is and it looks to be a constant run.

Called one non-main dealer garage today and he said it needed a main dealer because, if I get this right, they need to back pressure the system to find the leak - does that sound likely?

The car isn't worth much so I don't really want to spend main-dealer prices if I can avoid it, particularly if it's just for them to tell me the car done for.

[Nobby]

Head gasket gone if you're lucky. Head warped if you're not.
Talk to your girlfriend nicely and advise her that next time the temp light comes on , to either stop immediately or drive to a garage and buy a new car.

[DefTrap]

Don't run it any more for sure, if there's a big leak it can empty quickly.

I had a core plug leak on my car, basically wrote it off, too expensive to fix (I glued it, but I was lucky)

[KungFooBob]

Take it down the woods, set it on fire, claim on the insurance.

When the insurance pay out, don't buy a Vauxhall.

[Big Red]

Very common for water pumps.
If it is leaking from around the rear of the drivers side front wheel its the pump.
Also worth checking the small plastic pipe coming from the top of the water pump is still ok as these go brittle with the heat and just snap of leading to all the coolant getting pumped out. Vauxhall now supply a brass replacement for these. The broken plastic bit can be drilled out carefully.

[Beancounter]

Head gasket gone if you're lucky. Head warped if you're not.
Talk to your girlfriend nicely and advise her that next time the temp light comes on , to either stop immediately or drive to a garage and buy a new car.

TBF she pulled in as soon as she could, she was about to enter the Medway Tunnel so couldn’t stop as soon as the light came on.

I checked the oil (dipstick), the oil didn’t appear to be contaminated though I appreciate that doesn’t really mean anything. Girlfriend also says the car wasn’t losing power as she drove through the tunnel, though she wasn’t going for it.

Don't run it any more for sure, if there's a big leak it can empty quickly.

I had a core plug leak on my car, basically wrote it off, too expensive to fix (I glued it, but I was lucky)

It’s a pretty big leak from what I’ve seen.

Take it down the woods, set it on fire, claim on the insurance.

When the insurance pay out, don't buy a Vauxhall.

It’s a hateful car. My dad worked at Dagenham and my formative years were in south Essex so I’ve always had Ford’s. I would never choose to have a Vauxhall in my life. Wonder if I can convince her to get a Focus RS?

Very common for water pumps.
If it is leaking from around the rear of the drivers side front wheel its the pump.
Also worth checking the small plastic pipe coming from the top of the water pump is still ok as these go brittle with the heat and just snap of leading to all the coolant getting pumped out. Vauxhall now supply a brass replacement for these. The broken plastic bit can be drilled out carefully.

Hard to tell where the leak actually is, the visible run is on the driver’s side just behind the bumper but there are so many pipes and plastic covers that the coolant could be tracking from anywhere.

[ZRX61]

Don't run it any more for sure, if there's a big leak it can empty quickly.

I had a core plug leak on my car, basically wrote it off, too expensive to fix (I glued it, but I was lucky)

What the hell was it? I can buy a full set of core plugs for a V8 for about $20.

[ZRX61]

If the water is pissing out as quick as you can pour it in you shouldn't need to pressurize the system to see the leak. The tool they use to pressure test a system is cheap as chips (ok, $60 worth of chips).

Guy I knew overheated his Peugeot, he was trying to fill the radiator with a garden hose & finally noticed it was pissing out the tail pipe at the same rate. (Carl was involved)

[Mr. Dazzle]

What the hell was it? I can buy a full set of core plugs for a V8 for about $20.

It's the getting to them which costs, not the plugs themselves.

It doesn't sound like a head gasket from the symptoms you describe, its just a pipe/clip/seal/pump/plug that's broken somewhere. Or the radiator itself.

The trick is finding it! That's why they're telling you need a leak test machine. They're technically wrong, you could spend ages poking around, but they would obviously take the slightly easier route.

Other problem of course is that you may not be able to find the leak without the engine running and pumping coolant, so you see the problem there....

[DefTrap]

Don't run it any more for sure, if there's a big leak it can empty quickly.

I had a core plug leak on my car, basically wrote it off, too expensive to fix (I glued it, but I was lucky)

What the hell was it? I can buy a full set of core plugs for a V8 for about $20.

Old 406. Yeah the core plug was about a quid. To remove the engine to get to it north of a grand

[Beancounter]

If the water is pissing out as quick as you can pour it in you shouldn't need to pressurize the system to see the leak. The tool they use to pressure test a system is cheap as chips (ok, $60 worth of chips).

It doesn't sound like a head gasket from the symptoms you describe, its just a pipe/clip/seal/pump/plug that's broken somewhere. Or the radiator itself.

The trick is finding it! That's why they're telling you need a leak test machine. They're technically wrong, you could spend ages poking around, but they would obviously take the slightly easier route.

Other problem of course is that you may not be able to find the leak without the engine running and pumping coolant, so you see the problem there....

Tried filling the system this morning, and with a cold engine (not running) it's just going straight from the expansion tank to pishing out on the floor. Fairly confident the leak is at the front of the car and would be easy to trace (a) without pressure testing the system and (b) once you remove bumpers and stuff.

I might have a look myself. Might.

[Big Red]

If coming from the front drivers side in the bumper area, try checking down that side of the radiator. there is a coolant switch down there, seals against an o ring and held in place with a spring clip.