Radiator flush? Block included

[Benengel]

Afternoon all,
My radiator is pretty nasty and had dirt or rust in it, if checked a few of the hoses and they look pretty orange inside too.
Before I go buying a new radiator and hoses I was wondering if it is worth trying to flush the whole system.?
Iv flushed the radiator multiple times and this problem always comes back.
Iv heard you can reverse flush the whole block with a garden hose ?but this sounds like a bad long term idea for rust.
Iv tried to do the engine block bolt but that thing isn't moving.
Any ideas would be great

 

[Old.Tony]

I think you could only give it a go and see what happens. If you remove the thermostat and connect a hose from the top radiator hose to the bottom (removing the radiator from the cooling circuit altogether) then you could run a few flushes by idling the engine over for a minute, empty, fill with fresh water and repeat. You might even try a radiator flush additive.

Don't forget there's coolant in the heat exchanger and the overflow bottle. The fastest way to drain the coolant is by removing the bottom radiator hose. Be careful, coolant is really slippery!

When you flush the system, don't worry about using a garden hose. The water - if you use coolant (which has rust inhibitor in it) will not cause any harm to the engine. You need 33%-50% coolant-to-water ratio. The more water, the more effective the cooling system (ethylene glycol is good at increasing the range that water freezes/boils, but it's not so good at exchanging heat). I'm running 33% in mine, but I tow a lot.

Working on the radiator is a little different because it has the fine cores in it. If the radiator is really old, you might consider a new one - I bought one on eBay for mine and it's been good - but if you can see that most of your cores are clear, just give it a clean and reconnect then refill it.

I don't know if your D22 has a water-cooled turbocharger, but it will have a small amount of coolant in it too - that's why you run the engine to distribute the flush, it'll go everywhere. EGR cooler as well, if yours has one of those too!

 

[Benengel]

Hey thanks for the reply! Quite some good information !
If using the garden hose method would this do the heat exchange? Or should I do that separately?
Cheers Ben

 

[Old.Tony]

You might consider doing the heat exchanger separately, but by running the engine you're pumping the stuff through the heat exchanger anyway.

 

[Horatius]

I have an old thermostat I have cut the valve off. I take the good thermostat out, put this one in, empty/refill with water and run for five minutes. Then let it cool for a while, drop the water (from bottom radiator hose) and repeat as many times as necessary, until the water looks clean. I also take heater hoses off and give that a separate flush.

Then put thermostat back, pour 5 litre bottle of genuine coolant in and fill with water (keeping a little for the overflow). Works out to about 45% mixture, which is the mixture the dealers mechanics said they use. I'm anal though and use demineralised water for the whole process. As Tony says, it's probably not necessary.

Wouldn't bother fooling around with the radiator. You could get it cleaned professionally from a radiator place but it will be far more effective and not much dearer to buy a koyo aftermarket one. Last one I had cleaned sprung leak anyway after all the corrosion had been cleaned from the cores. That was a while back though on a different vehicle, but wouldn't bother cleaning them since.

ps. this is my method on an old zd 30 though, not sure how much different yours will be.

 

[Old.Tony]

^ It will be no different to yours. Radiator cores block up on any vehicle. I also replaced my entire radiator with an inexpensive aftermarket one and have no trouble with it. We towed our 2.5T caravan through the middle of Australia this Christmas just past, and had zero issues with the cooling system.

 

[Benengel]

Cheers for the replies guys,
I got quoted 120 for the pros to do it. Which might be the go.
Just find it hard to trust mechanics now adays as only half of them do what you ask...

 

[Horatius]

Cheers for the replies guys,
I got quoted 120 for the pros to do it. Which might be the go.
Just find it hard to trust mechanics now adays as only half of them do what you ask...

Go for it mate. It costs me about 70-80 bucks just for the deionised water and coolant. I feel the same with mechanics, unless you find a good honest one who has reasonable standards.