Originally Posted By: KrisZ
Originally Posted By: The Critic
Originally Posted By: mechanicx
Originally Posted By: Audi Junkie
Should I forget about it?
At 3 years old.
I think if you are just doing radiator drain 3 years is time to do it, since you're not going to get all of the old coolant out. I know Honda says 10y/120K for first change and 5y/60k subsequently, but they mean a complete change and I just think 10 years is ridiculously too long. A full change every 5 years or at least 1 radiator drain every 2-3 years seems more reasonable.
Honda wants you to drain the radiator and engine block at 10/120k.
Then it wants you to perform the same service every 5/60k thereafter because you do not remove all of the coolant if you follow their service procedure.
Coolant does not need to replace that often unless your vehicle has a reputation for cooling system issues. I would not even consider it until 100k at the earliest. However, instead of just replacing the coolant at 100k, I would consider a complete cooling system rebuild-- radiator, water pump, all hoses, radiator cap and thermostat. I have personally seen a lot of cars with just over 100k that have been overheated due to cooling system leaks, and a preemptive cooling system rebuild would have saved them.
So you would leave the coolant for 100k or ten years, which would cost about $20 to do a complete flush yourself, and instead, totally rebuild the cooling system which would cost much more? That's one funny way of looking at maintenance.
Also, these components last much more then 100k and only need replacing as needed, i.e hoses are soft or are showing cracks, water pumps usually leak before total failure, the systems you speak of must've been severly neglected and cracked hoses and leaks not attended to in time, thats is hardly a proof that you need to rebuild cooling system every 100k. I'd rather change coolant every 2 years than rebuild cooling system.
+1. A stitch in time saves nine. Spend a little time keeping things clean and the chemistry refreshed, and you save a lot of issues down the line.
The degradation of the chemistry is not linear, it is logarithmic in some way. This means that there is some point in time where the activity of the coolant for protection is great, fast, and really capable, then there is a point in time where the adds do not deplete quickly, but the buffering activity, etc. are far slower.
Any high school chemistry titration experiment will show this.
While both will likely be god enough to prevent warranty issues through the normal lease period or CPO period (all they really care about), there is a better way to do it.
Never could understand why folks gripe about $18 coolant in a $1000+ system on a $15k+ car. Change it and protect it.
And all that said, changes enable you to keep parts for a LONG time. I have multiple cars with >200k on all original parts. The most unreliable thing is the plastic radiators that toyota and Honda use, which will leak even with coolant changes. My MB plastic top radiators are still like new after 30 years...