Flushing out the cooling system..

My X is suitably protected against the frost and winter with loads of antifreeze. However in the spring I would like to get the whole system flushed and replenished..

So is there a way of power flushing it and i presume if cold water is used the thermostat will close and it wont flush the engine properly...

Previous experience suggests that most of the silt, scale and rust ends up in the radiator. So, take it out, flush it forwards and backwards, shake it upside down and repeat until no more crud comes out. then refit and refill with new coolant. If no improvement, its probably time for a re-cored radiator :ohmy: If you use a flush product they direct you to bring the engine up to temp so that the t-stat opens up.

Flushing the radiator is a bit hit and miss

If you're lucky the solids have not settled properly and will flush out *but* if they have then flushing will either not work or result in damage to the cores as the congealed solids tend to take the core with them when they depart...

Unless the engine has been treated properly to a decent anti-corrosive agent all its life then there will be solids in the radiator and you'll probably find they have congealed into a very solid mass!

A car that is 30 years old will typically have a function loss of 25% to 50% of the radiator. A flush might restore 10% to 15% of that, the result just won't move. Using a chemical flush might move it but I refer you back to my original statement.

In the end a recore isn't murderously expensive and makes a big difference to how well the cooling system performs. Companies like Serck Motorsport can do a rebuild to a very high standard without costing the earth (I don't think Serck Marston exist anymore although there are still sites in most large towns), they also do a full on cleaning service so if you're not too far from Hayes it might prove an alternative.

the system is in good order and performing well even stuck in traffic on one of the hottest days last summer. I just wanted to know if there is a preferred way of flushing the whole system to give it a thorough clean out...

Doesnt sound like you have a problem - just keep the coolant changed on a timely basis and the anti-corrosion additives should keep it all clear - Prevention is better, easier, cheaper than cure!

I'm a mechanic & have done hundreds of 'em. By far the best way, bar none, is flush it the opposite way the pump shoves it around the system. Lots of the crud hides in small crevices & the like behind casting webs etc. when you flush it backwards, it's more prone to clear it.
Usually works well on things like the x19, because rad a lot further from the engine, if you disconnect the hoses from the engine & flush the front section separately. You'll be amazed how much cack comes out.
Julian

Thanks for the advice.. Certainly a job for the spring but one I want to do and maybe then install that new waterless coolant.

Just wondered if there was an easy way to do it by maybe modifying an old expansion tank cap to fit a hose straight on and flush it all out. Also if it was done with cold water would it flush out all of the engine as the thermostat would be closed shut..

Remove old rad and chuck in the bin

With front and rear rubber hoses removed- raise front of car and blast a power hose down the steel under floor pipes, as this is where most of the crude will be lying

Three bolds removes the thermostat Terry, then you can flush the engine backwards and forwards till your hearts content

Finally- Fit Scirocco radiator and never worry about your cooling ever again

Charlie, thanks.. I want to make the France run in the summer so I want to make sure the cooling system is up to scratch. It's been ok so far no over heating or problems but I do get some scum in the header tank. Although when the engine is running and the coolant pipe to the carb is disconnected it does run nice and clear. so obviously it does have some residual crude in there..

All good advice, but I have found that the largest deposits of 'crud' can be found in the metal pipes connecting the radiator to the engine. To clean these out you need a length of strong cable secured (and I mean really secured) to a stainless steel scouring pad that is a loose fit in the pipe. Feed the cable through the pipe and pull the scouring pad through with a flow of water, repeat as neccessary.