3rd gen HELP HELP HELP- heater

[520ft/lbs-roadeater]

Did you try with and airline?

I don't have access to a half decent airline at the moment. I will have at the weekend on the farm though. I let some cleaner flush stuff sit in there for a about 4-5 hours and then flush out with a half decent garden hose. Didn't see any debris that I would say were blockages though. Cheers

[andyverran]

Water might pass through freely but any scaling on the tubes can inhibit heat transfer. If you live in a hard water area , or your Surf has, and previous owners have been topping up with tap water, not bothering with a decent coolant mix, all this is quite possible

If it is scale, I've had some joy in the past using kettle descaler (having removed the matrix of course). Filled the matrix and left it an hour, jobs a good un.

[Yorkshire Devil]

Matrix block

If it is scale, I've had some joy in the past using kettle descaler (having removed the matrix of course). Filled the matrix and left it an hour, jobs a good un.

Caustic soda often is good as a last resort and usually the best cleaner you can use.

[Jameswallace]

Makes sense about the scale

I live in a hard water area, but i do use a high percentage of antifreeze

Is there a descaler you could run throygh the entire cooling system or would that be a recipe for disaster

[yoshie]

Makes sense about the scale

I live in a hard water area, but i do use a high percentage of antifreeze

Is there a descaler you could run throygh the entire cooling system or would that be a recipe for disaster

Yes as I said above a two part system, second flush is used neutralise the first. Didn't work for me as I already said.

[tashtego]

Makes sense about the scale

I live in a hard water area, but i do use a high percentage of antifreeze

Is there a descaler you could run throygh the entire cooling system or would that be a recipe for disaster

It's better to always use distilled water for the cooling system, especially if you are in a hard water area. Unless you use a premixed coolant, like the Toyotas or Halfords type coolants. In that case you don,t need to add extra water.
Cheers

[Karma Supra]

Did you check the second part I suggested under the dash?

[520ft/lbs-roadeater]

Did you check the second part I suggested under the dash?

Yeah man I did.