Will Flushing my radiator damage me car?

Question

I have a 2002 Chevrolet Cavalier that has 140k miles on it and the radiator has never been flushed. I am now on the verge of replacing my Heater Core and was told I will need to drain my radiator. I figured since I have to drain it I might as well flush it but during my research I have found people saying that flushing the radiator on a vehicle that has never been flushed and has over a 100k on it could potentially damage the vehicle. The reason being that the flushing the build up in the radiator may not get it all out and when reconnected the sludge could cause damage to the vehicle. Should I Flush it or just drain and refill?

Answer 1

If you have to replace the heater core, your cooling system is already shot. Do NOT waste time and money trying to flush the radiator/cooling system. Drain it, replace the radiator, replace the heater, and done.



You can't flush out the scale of a radiator. That is why "rodding" used to be/is done to try and get more life out of radiators. Of course, then the radiator core walls are thinner and more likely to spring a leak. Which is why it is far better to spring the $~150 for a stock replacement radiator. Unless you engine engine failure and/or getting stranded when it lets go.

Answer 2

It's possible. First, a flush with flush chemicals can dislodge corrosion that's clogging pinhole leaks. Then you'd have to replace the radiator or heater tubes.



And yes, a flush can disturb any buildup and then push that crud into the new heater core and plug it. But that's if you do a lousy job of flushing.



Then again, let's define flushing versus drain and refill. A flush is really a backflush with a machine that forces air and water backwards through the system. If you're concerned about sludge buildup, you add a flush chemical to dissolve it and then continue flushing until the water runs clear.



A drain and refill carries less risk because it usually doesn't disturb buildup.



don't know if that helps. But I do know that you most likely killed your heater core by not keeping up with maintenance. Read this post on what happens when you run too long on coolant.



http://ricksfreeautorepairadvice.com/repair-topics/cooling-system-service/prevent-damage-to-your-heater-core-and-radiator-by-checking-your-coolant-for-electrolysis

Answer 3

i think they are talking about not to flush the transmission, not the cooling system ! i flushed many cooling systems and never had any problems ! with that many miles go ahead and flush out the whole cooling system, including the heater core , change the thermostat and bleed the air out after you fill it with 50/50 antifreeze by leaving the radiator cap off and start it !

Answer 4

It might start to leak>> flushing out all the rust and gunk could make a few weak spots leak Not like it is was not going to fail later on. you might want to know it is going to fail now rather then on a trip ..

Answer 5

Not if done properly.

Make sure that the proper antifreeze-water mix is used.

The end result will be improved engine cooling AND cab heating.

If unsure how to proceed, have it done by pros. Make sure that the system is also bled properly to avoid airlocks (engine overheating, no heat in cab).