Thread: Active engine mounts solenoid

Yes, from memory my MY10 D4 3.0 had this. The vacuum is from a plastic pod set in the V iirc. The lines run to each of the engine mounts. The solenoid controls the engine mounts, open and the vacuum created holds the engine mounts in vacuum.

Thanks Eric. The plastic pod will be the reservoir which is hidden and why I cannot find a spare barb on a T-piece. The inlet hoses need to be removed anyway to re-route a turbo boost sensor hose.

I remember at the front of the engine, below the aux belt, there is a barb for connecting the hose there. There is also a one way valve in that line if I remember right. Cars been gone 2 years, I replaced all the vac lines and fittings at 200000km including these active engine mounts. Then the engine mounts as well as one had collapsed.

Thanks Eric.
It appears that the T wasn't refitted, somewhere. One picture appears to have only 2 lines going back to the pump with the 3rd, the breather, going to the airbox whereas this vehicle's breather for the front solenoids goes back to the pump. Another picture shows the airbox breather connection dropping down presumably to the engine mount solenoid. The system maintained vacuum over a few hours so there isn't an open vacuum port.
My plan is to T into the vacuum line just before the reservoir and likely before the valve, assuming that a chat with the mechanic isn't fruitful.

I recall that Rimmer Bros or one of the vendors actually shows the vac line routing, another option would be the factory manual.

I cannot find any diagrams for this solenoid, not in the WSM nor anywhere else. The closest is a picture of the solenoid c/w bracket and the short vacuum and breather tubes attached. The workshop manual doesn't even mention it, not that I can find anyway. I had to disconnect the solenoid, which was attached to the electrical harness but poked down out of sight until I wondered what the harness was that dissappeared down between the plastic box and the coolant pipes, to see what fault was triggered. I had owned the car for the first 6 years of its life and didn't know that it had active engine mounts.

I'm still learning about these vehicles, such as the ecm has to be told when a new crankshaft trigger wheel has been fitted because the fitting tool can't sufficiently accurately locate the ring, or when an injector (or 6) has been changed to discard old calibrations and shortcut injector learning. It currently idles rather roughly, sending vibrations though the body but becomes very smooth just above 1000 rpm.

Screen Shot 03-10-25 at 06.24 PM.jpg

The solenoid is plugged into connector C2262, the location in the drawing here is a bit deceptive, it's on the engine side of the plastic "wall" which is presented as transparent in the drawing.

If I had a D4 or RRS here right now I'd take a picture for you, sorry.