Aluminium radiator vs Copper/plastic/stock radiator

turbo77 on 31/10/2013 - 22:40

i have read numerous opinions on this topic on other forums, but i have just replace my engine with a very low km engine.

i have had the car for about 8 years when new and its done 200Ks on it. so would it be best to upgrade to a fresh radiator too to help with cooling efficiency? and is an aluminum radiator better in cool performance then a stock plastic copper one or is it just bling?

few weeks ago it was 30 odd degrees and i felt my aircon getting weak then cool then weak warm again while the car running for 20ks stop and go.

read about the air con does this to put less stress to the engine from preventing over heating.

i dont know if my radiator is corroded or not but last year the mechanic used red coolant instead of green that i have been using for the last 7 years.

Automotive

Comments

  • Speckled Jim on 01/11/2013 - 09:07

    I'm in a similar position. My stock rad has a hairline crack in the top tank (plastic). I was going to use JB weld epoxy to repair it, but then saw how cheap new rads can be on eBay.

    Anyhow, I was under the impression that the finned elements in stock rads were aluminium. The rest being plastic and pressed steel for the frame and brackets?

    But I'll probably just go OEM. They're generally cheaper than the "race" alu ones.

  • [Deactivated] on 01/11/2013 - 21:04

    The aluminium ones I've seen still have plastic tanks.

    Copper transfers heat better than aluminium. But on the other hand, copper degrades faster/more easily. I've had a few radiators that looked fine, but the copper just crumbled apart with a slight touch.

    So while a new copper one would radiate slightly more heat away than aluminium, a new aluminium would be more efficient than an old copper. But the difference wouldn't be enough to worry about unless you're in the outback. If the water is slightly hotter (because the aluminium isn't cooling as well as a copper one), the thermostat will simply circulate the water a little longer until it does cool, and the thermostat then closes again.

    There are also ways to make up for the slight difference. For example you can change your coolant mix (if it uses any water) to straight coolant. Or change the type of coolant (I believe the main difference between red and green coolant is red lasts much longer, so it doesn't need renewing as soon). Mechanics also mark up everything they provide for your car by a certain percentage - and red coolant costs more than green. So the mark up is higher = they make more money, even though they'll probably still change the red at the same time they would have changed the green.

    If it really worries you, and if it's available, you could change your thermostat to one that opens at a lower temperature - so the water circulates (and begins cooling) sooner. (But if you lived in the snow for example, you probably wouldn't want to do this. The car would always be "cold" and probably run rough.) You'd have to check wherever you buy parts if you can get a lower-temp thermostat though. I suspect though when they ask and you explain why you want it, they'll probably tell you not to bother.

    If you're replacing the radiator yourself, make sure you fit new hoses at the same time. (Old ones can fail.)

    BTW… I expect the main reason for the change to aluminium is the market price of copper.

    Oh - and if your air con is turning off and on, that may be some kind of cooling protection on your particular car - but I do know it's also a classic sign the aircon has a leak repaired, needs regassing, or both.

    • [Deactivated] on 08/11/2013 - 08:55

      … has a leak TO BE repaired.

    • Speckled Jim on 08/11/2013 - 09:26

      The aluminium ones I've seen still have plastic tanks.

      Here's one you haven't seen.
      They're legion on eBay!

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