Couldn't agree More Montegue,
For years I thought Prestone was cheap old stuff, probably because it was sold in Halford's ( not the only source)and the yellow bottles don't inspire either, but I was educated by a racing mechanic and I really haven't looked back. I have even done the test using another well respected and known product then repeated it straight away using Prestone and what still came out was filthy. Just to confirm it wasn't the two flushes that did it I flushed my son's car both times with Prestone and the second flush was totally clean! Make what of that you will but it sold it to me!
You Didn't say whether or not you were going to use the Prestone flush first. Of course garages when they tell you they have flushed the cooling system don't do anything other than change the fluid. As I said, when I drained my old fluid out it looked like new. It was only when I used the flushing agent that I discovered just how filthy with retained muck it was.
Re. the bleeding, It is the simplest coolant change to a car I have ever done, there really is no issues and a couple of flushes allowing the stat to open fully flushed the whole system and as you have to have the thermostat open to achieve this I found this to be the simplest method.
De-ionised water is obviously the best but I just stuck with the trad Distilled water for the final fill. My water here is very soft, we have no limescale issues at all, not like when living in Kent! However if I had hard water I would be a bit reticent about using tap water to flush it too. I'm like you in that I really don't trust what I am told about my cars service history or what a garage writes as opposed to what it actually does...... I've seen the lies first hand and suffered from them myself too many times. Yes, I too have to base line all my cars that I get which aren't new, and in fact 18 months ago I bought a new Suzuki Jimny as a house car, fishing and dogs etc. for our small Welsh farm roads here and it's never been back to the garage and I have no intension of it ever going there either.
I was in a main dealer a few years ago and I heard the mechanic being given a car for an oil service and he was told "no filter needed, just an oil change! Two things here, they fit the cheapest sh!t anyway so why would they expect it to function well for two years? And why not fit the best as its only a tenner more anyway.
The final straw for me was my sons car went in for an MOT and and oil service to a respected independent. I gave him my card when I dropped him off as it was mayhem and I couldn't park. They charged him just shy of £400.00 Dick Turpin on the till obviously! When He got home the car had not been touched, black oil (petrol engine polo) cabin filter filthy, air filter filthy, washer bottle empty tyre pressures all different. When I serviced it the oil filter cartridge was the cheapest aftermarket option available from a previous service they had done and it was so knackered it had splits in the internal folds. That was it for me, Now no twot touches any of my cars anymore. I'd hoped at 60 odd that I could off load some work but clearly not so I'm back at it again on all the cars!
