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Discussion Starter #1
I plan to go through mine this spring and replace all the hoses, thermostat and coolant.

The car will be 10 years (since I picked it up at the dealer) old this month. Never had issues, but I know the stuff won't last forever.

I bought Hyundai hoses, thermostat and anti-freeze so I hope they'll last as well as the originals have.

Questions are:
1. How much flushing is required - how many times to feel good about getting as much of the old stuff out as possible
2. How did you flush it? Just pull the bottom hose loose from the radiator, let it drain out, refill with distilled water, run it till hot, repeat? Or did you do that part differently?
3. Is it hard to burp the air from the system?

Worst one I've messed with in 40 years of doing this is my IROC Z28. Have to let it run till you feel the hose on the thermostat housing starting to get hot and then shut it off or it will get really hot as the thermostat hasn't opened. Let it sit and you can hear is clicking, popping, gurgling as air slowly seeps by the thermostat and water works it was upwards in the block/manifold. Fire it up the 2nd time and the thermostat usually opens when it get to temperature and then you can run it just a bit, shut if down again, let it cool and add anti-freeze to top it off. One last time of running till hot, shut it off and top off the overflow tank and that takes care of it.

I sure hope the Coupe is quicker/easier, but that's why I'm asking ahead of time.

Thanks for any experienced suggestions.

I'd rather do it myself
19,120 Posts
Not sure on the 3.8L on how to get the most old coolant out. I usually use the lower radiator hose, vent the top somewhere. If any hoses between the pump and t-stat area open them too.

To flush I usually use a citric acid type cleaner. Put it in and drive a day. Flush with clean water, flush with distilled water and drain as much as possible.

Then refill the first gallon using 70%, top off with 50/50.

I generally don't bother with the burping as if the system is 100% leak free it will self purge of air. I do drive and let it cool. Then top off for the next three days or until the radiator stays full when it's cold.

Using a clear overflow hose allows you to see instantly if the radiator is 100% full without removing the cap.
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