Volvo Penta 2003 - Cleaning Water Distribution Pipe

[rowansmith]

Hi,

My Raw Water cooled Volvo Penta 2003 has been overheating. I am replacing the Exhaust Mixer.

On inspection of the, (is it brass), distribution pipe which runs through the engine block I discovered it was clogged up and only has a small 2mm diameter hole at the inlet end.

I also lifted the thermostat housing and found white gunk everywhere, but the area was relatively clear compared to the cooling tube. I know the thermostat works because a calorifier is in the circuit and this and that heats up.

To my questions:

Is it possible to remove this tube for cleaning? Or should I try and descale it in place by pumping a descaler such as Rydlyme through it?

Should I be pumping decaler through the engine block as a whole? Where is the best point to exit the descaler? (I have an anode I will have to remove and plug up, is this a good place to attach the return hose?) Or is their a better place?

Thanks very much.

[DougR]

Yes, the water distribution pipe is removable, but if it’s that scaled up you might destroy it during the removal process.

I think you might just remove the thermostat cover and fill the head and block with the descaler and let it sit and do its thing, cleaning the entire block and head with the pipe in place.

DougR