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Coolant flush question

5.2K views 19 replies 9 participants last post by  egads  
#1 ·
Hi guys, so am gonna do the coolant flush on my 2012 oddyssey and well i seen videos that only really say to undo the petcock and let all the coolant drain, my question is what about the cololant thats in the engine? Is their a way for this to get drained or is their any coolant in there or is it too little of a quantaty that it doesnt matter?? Thank guys in advance
 
#2 ·
There should be a drain plug for the block.
 
owns 2006 Honda Odyssey EX
#3 ·
Checking my notes from doing this on my 2011 (will be same as your 2012):

location of engine block coolant drain: directly (about 6" away) above the inboard edge of the right inner CV joint. It is 12mm hex, brass, with a hose attachment in the center. Easy to get with 12mm ratcheting wrench.
 
#8 ·
with a hose attachment in the center
Takes a 5/16" ID hose.

Hose is optional of course, but it practically eliminates any mess (from that port anyway).
 
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#4 ·
what about the cololant thats in the engine?
Or the heater core, or the rear heater core and lines? There's a lot of coolant in the system. You'll get a bit more out by draining the engine at its drain.

-Charlie
 
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#5 ·
You'll never get it all out. That's why despite the factory fill being good for 10 years, they recommend every 5 years after that.
 
owns 2006 Honda Odyssey EX
#6 ·
On my '02 I will disconnect heater hoses by firewall and gently blow out the cores with comp. air. Not sure of your layout.
 
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#9 ·
Get the coolant exchange by the dealer or other shop. It gets all of it. Nobody will actually 'flush' one anymore because of the problems involved in getting rid of a large quantity of water mixed with coolant. Whatever, either use the pre-mix or get distilled water to mix. Do not put any tap or well water into the system.
 
#10 ·
What magical method does "the dealer or other shop" have that allows them to do this, other than that the customer won't know what they are actually doing?

I would not be surprised if "the dealer ..." does not even touch the engine block drain. New coolant looks the same as the old coolant. Most customers don't know what coolant is, and won't even open the hood.
 
#11 ·
I will say this is one thing I would trust the dealer to do over most independent shops. I have confidence that I would at least get Type 2 coolant installed, not some "universal" coolant.

I don't see shops flushing their flush machines between vehicle brands so as to stay within manufacturer specs for correct coolant.
 
#12 ·
I don't see shops flushing their flush machines between vehicle brands so as to stay within manufacturer specs for correct coolant.
I suppose you need a flush machine to flush the flush machine...but then how do you flush that flush machine? o_O
 
owns 2006 Honda Odyssey EX
#13 ·
To start with, its not a 'flush'. Its a 'Total Fluid Exchange' that pushes out the old coolant while drawing in the fresh coolant. They have to dispose of the used coolant but its a smaller quantity than it would be if flushed with water - plus, that tap water would be unsuitable for use.
Why is it that the most ignorant are also the most loud and brash when they demonstrate their lack of knowledge?
 
#14 ·
Why is it that the most ignorant are also the most loud and brash when they demonstrate their lack of knowledge?
Please share with us the answer from the (wo)man in the mirror.
 
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#16 ·
So I'm gonna be the guy who asks why you are doing a coolant flush? I know there is a 120k service interval, but I also know it usually gets replaced when the timing belt gets done at 105k (ish). There is no reason to flush the coolant on most Hondas. My 2002 only got coolant at both timing belt replacements. Our 2003 went to the crusher at 300k with the second coolant change still in it. It spent a lot of it's third 100k going back & forth between Northern & Southern California up over the grapevine. Never overheated. Real Honda coolant is very good stuff. You should never drain it early just to replace it with something generic. It's not a Ford or a Mazda.
 
#19 ·
but I also know it usually gets replaced when the timing belt gets done at 105k (ish)
The weasel word above is the reason why some should/do change it at 120k.

I fully agree with and follow the practice you seem to advocate/follow, doing the work myself. But a lot of people are extremely price conscious, and so wind up getting TBs done by low priced shops who reflect the cost consciousness.
 
#17 ·
OP is at 10 years, the age at which the factory fill coolant should be changed.
 
#18 ·
So the timing belt & water pump have never been changed? I'd worry more about that. And go ahead and change the coolant. Flush? Not so much. Did anyone here point out how important having both front & rear heaters on full during the process? It was my experience after the second timing belt service that I needed to top off the coolant about a week later once the whole system had burped itself.