partially blocked radiator - washing powder flush?

[james_16v]

Hi all.
The mrs 1.6 driver has been getting very warm at motorway speeds (fine at idle and sub 40 mph).
After replacing a few split hoses and flanges i just checked the rad and its barely warm by the fan switch end but hot at the opposite side.
Before i stump up for a new rad i want to try a flush.
Ive read about using washing powder, would anyone recomend this or a specific flushing product?
Cheers

[Thom89]

Sounds like water pump may be on its way out, impellers can corrode away, or become detached from the shaft, losing efficiency at higher engine running speeds, a new thermostat may be a good idea too... flushing the system is a good place to start though, drain system down, and flush as much out as possible with a hose to get the worst out.... then add a mug full of washing powder slowly to the system, Persil works wonders... let it run in the system for half an hour or so, drain, re flush  and replace with just water, take the car for a drive to test, if OK, drain some water out, and top up with antifreeze
Thom

[james_16v]

I initially thought water pump but i can see a stream of water from the return hose with the cap off albeit not all that strong.
Ill start with a persil flush then and see where that gets me.
Cheers

[clipperjay]

Holts two part flush will do the job not sure washing powder might leave a residule that would stick on the heater matrix or block channels wouldn't risk it TBH?

[james_16v]

I was eyeing up the holts 2 part flush but the washing powder trick is cheaper!
Assumed that washing powder would be well dissolved at cooling system temps, my concern was if it was rugged enough to shift the deposits in the rad??
Ill give it a go and if it dont work ill whip the rad out and give it good flush through

[emery1990]

If it you too use the persil, then you could just flush it a few times with hot water to absorbed all the film ( if it even leaves one) i know dish washer tablets too, the water becomes very slippery