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I picked up a used radiator and have no history on its use.
What measures should i take to ensure it is clean inside before adding premixed Nulon coolant?
Should i just add in demineralised water, run the engine till hot, and drain?

How do the end tanks look?

If they are rather brown, up I are better off getting an aluminum one.

If they are still in good nick just pump the garden hose through it while it's out of the car

Top/bottom tank are black, so good color. Very slight mark on the upper hose connector (looks like a hairline crack), but in a lot better shape than my old radiator which was going greenish brown, and orange around the hose connector area.

Should last me a while i think. If it goes brown then ill upgrade to an aluminum ASI (hopefully when they get the 42mm for the NB in stock...?) or a coolingpro.

Thanks - will run tap water through it. Cheers.

This is probably a stupid question
but i was just playing with the radiator cap on my replacement radiator. when i unscrew the cap, i dont need to push it down to get it off.
on my original/old radiator, the radiator cap wont come off unless i push it down and twist.
anything i should be concerned about?

Sounds like it's not locking, so either the tabs on the cap or the tabs on the rad are broken/ bent/ missing, or the spring loading of the cap inner stem is U/S.

spring on the cap is fine...tried on the old radiator and it needs the 'push and twist' to get off.
i had a closer look last night and it seems to be the tabs on the actual radiator itself. they look a little worn so the cap is probably not 'locking' in place?

does it need to lock?

wiztek wrote:does it need to lock?

When hot the radiator is pressurised, so personally I'd want to ensure that it couldn't work loose over time, inadvertently be partially turned, or be removed other than by consciously pushing down to disengage tabs & then turning.

ugh, i knew i shouldve just spent the extra $$$ and got the ebay ASI.

wiztek wrote:...it seems to be the tabs on the actual radiator itself. they look a little worn so the cap is probably not 'locking' in place?

If this is the case, then you might be able to adjust the tabs on the rad cap to compensate for partially worn rad tabs.

just take it to the local radiator shop and ask someone to take a look for you- cost you nothing.

To clean a radiator properly you need to remove the top and bottom tanks. All you can do otherwise is give it a good hose out, which does very little to remove rust and scale inside it. You will spend more than the cost of a new Chinese copy rad from ebay etc getting it serviced at a radiator shop, so might as well use it as is or buy a new one.

I just changed the radiator over and started the car up
LOUD bang on start up. Engine runs fine. Fans all working it seems.
Started the car for a second time, loud bang still there. WTH?

If it matters, the cars been sitting for a week with the radiator and intake out/off.

What kind of bang? hammer on anvil bang? or explosion bang?

If former, perhaps something around the starter motor housing/brackets have come loose.
If latter, then something amiss in the fuel system, eg. leaking fuel after shutdown hence fuel vapours in exhaust, or even intake, igniting.

Unless you are VERY confident in the condition of the used rad, I would leave it and buy a new one. It's an expense you only have to fork out (hopefully) every 7-10 years or so.

Yes im starting to realise how stupid it was to buy a used radiator.
Any i started the car for a third time and no ominous bang/pop/explosion. I think it was probably just fuel igniting or something as there was some black debris coming out of the exhaust at first. I have no idea why this would happen though. Is there anything obvious i can check?
Im going to just run around with this radiator for a while and then get a aluminium ebay rad