Cleaning muddy radiator?

[Disco Matt]

Any ideas for cleaning mud out of a radiator without damaging it? At the moment I'm thinking low pressure hosepipe. Would WD-40 help (thinking if the mud is suitably wet the WD-40 might be able to get underneath and lift it off)?

[crazymac]

I know some will slam me for this, but I just take the pressure washer to it!

Front grill off and blast it. Its powerful but not high volume, so does the job nicely

[Disco Matt]

I also have a slight problem in that I have the aircon rad in front of the main one. There should be enough space to get a hose in with the upper radiator securing plate off though.

I was thinking about a soft brush but given how thin the fins are I'm not sure it's a good idea. Lots of running water would seem to be a better bet.

I had a slightly scary moment with temperature gauge rising dramatically on a long hillclimb. As I don't appear to be losing coolant or oil (and they don't appear to be mixing, the heater works too) the mud on the radiator is my first target. The car sat at 60mph on the way home with no repeat of the problem, presumably as the increased airflow at road speed was an improvement on thrashing up a steep hill from a standing start and getting into 4th.

[M6GKX]

Yeah, I used a hosepipe in the Defender last weekend. Took the front radiator cover/grille cover off and then worked my way along horizontally front and back.

Spent a fair bit of time making sure I got it right as don't normally have the facilities to do this  :-.

[Disco Matt]

Just been in there with a plant sprayer to wash it off the fins and a bamboo cane to hook the muck out of the space between the rad and aircon rad. I'm amazed it hadn't overheated spectacularly considering the amount of mud and leafmould I fished out - there had to be enough to grow a medium-sized houseplant in there!

[M6GKX]

Yeah, I was surprised by the amount of mud between the aircon rad and the main rad on the Defender. Not as much as the amount hidden in the nooks and crannies of the wheel arches! But even so, it's worth doing.

If that had failed I have been told of another method which was to remove the two radiators and take them down to the local radiator shop who could put it in a large bath of water and blow air through it overnight whilst shaking it.... But they charge a fair bit for that  :-. and I'm not exactly rich running a V8 Defender  :roll: :lol:

Still, you've got it sorted now :D Also, if it's got hot enough check it hasn't lost a bit of coolant...

[Disco Matt]

I checked oil and coolant straight away - was worried I'd blown a head gasket! No sign of emulsified goop in either though, and the coolant levels were normal. Think it must have been objecting to hammering up a fairly lengthy hill at low speed.