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[Valentin]

Hi guys,

I can't find if the electrical water pump on an X30XE from MY96 must stay ON after switching engine OFF.

When I switch OFF the car while fans are ON, they stay ON a little amount of time, like 15 seconds. But the water pump switches OFF immediately after switching OFF the car and I can see the temp gauge still increasing sometimes until 100°C. So, I switch ignition ON again and can hear the pump running, and the gauge stabilizing or slowing down the increase of temp. Sometimes, I even start again the engine and blip throttle to accelerate the water flow and cooling down... Logic isn't it ? 

Every time I park, i carefully observe if the car is in temp increasing or decreasing phase, and it's a bit annoying I have to say Because I don't know if it's normal or if there can be a risk of overheating even after engine is OFF.

FI : coolant, calorstat (thermostat), valley of death fully cleaned with new stainless steel oil cooler, all is new from 2025 summer and the car's behavior was already like that before those changes.

Thanks, have a nice day

[Doctor Gollum]

Normal behaviour.

The fans are switched by thermoswitches in the radiator.

That pump only runs if you ask for cabin heat with the engine off.

Apply 12v to the pump to check it actually runs.

[Valentin]

That pump only runs if you ask for cabin heat with the engine off.

Apply 12v to the pump to check it actually runs.

My pump runs even without cabin heat ON, it runs as soon as the ignition in ON. Or I didn't know I can ask for cabin heat while the key is out of ignition

I'm sure it runs well, I can hear and feel it vibrating

Ok so it seems normal to have a quite big increase of temperature after switching OFF the car even if it's done a complete cooling phase and it's at the lowest. I can't imagine if I switch OFF when the temp is juste before triggering of the fans. They might start but the water is not moving 

[Doctor Gollum]

Exactly. Don't underestimate the role of the mechanical water pump in regulating the temperature 

If you think the 3.0 runs hot, the 3.2 puts out enough radiant heat to defrost the driveway

[polilara]

How many electric pumps you have? I have two and I thought that they work like discussed below; one for preventing afterboiling and the other to give heat to cabin when engine stopped.

https://www.omegaowners.com/forum/index.php?topic=130392.0

[Valentin]

How many electric pumps you have? I have two and I thought that they work like discussed below; one for preventing afterboiling and the other to give heat to cabin when engine stopped.

https://www.omegaowners.com/forum/index.php?topic=130392.0

Okay after reading this topic, I discover there are 2 pumps as you said.

If I understand, the one mounted horizontally under the collant tank is directly linked to the cabin heater. This one is always ON when ignition is ON.
The other one mounted vertically near the front radiator and battery is connected to the radiator bottom right/top left crossing the natural flow top right/bottom left (view car in front of you).

I need to check if this one is alive too. And I don't really understand its purpose, as it doesn't flow the water through the engine but only in the radiator.

They are exactly the same when you search with both references https://nemigaparts.com/fr/cat_spares/epc/opel/v94/f/20/