straight coolant. Needed your input,please! [Archive] - Drive Accord Honda Forums

: straight coolant. Needed your input,please!

05-28-2010, 07:09 PM
I just talked to the mechanic who did the 120k service for my car and found out he put 100% straight coolant in the radiator:( I thought he put 50/50 as the manual said.... anyway, how bad is the straight antifreeze/coolant gonna do to my car? do i need to flush the whole system and replace it with the honda type II? is it ok to just drain and refill? or is it ok to drain it a good amount then refill the radiator with distilled water?
Sorry, there are so many questions 'cause my knowledge is limited

05-28-2010, 07:45 PM
Honda coolant is already 50/50 and isn't diluted in use. Maybe that's what he meant? Let's hope so. But you need to find out exactly what he used.

If he used another brand that has a silicate formulation, then you have to flush the system very well, or it will destroy your water pump seals. If he did this, your mechanic knows zip about Hondas.

If he used a non-silicate formula but simply failed to dilute it, you'll have trouble getting it down to 50% precisely but it can more-or-less be done if you tinker with a hydrometer (floating balls in a big eyedropper to measure density). But it's a lot more straightforward to dump the coolant, premix a new 50/50 solution (or use Honda Type II at full strength) and refill it. Really, I'd much prefer the Honda refill, after a flush or two of the system.

05-28-2010, 08:56 PM
he used Preston with 100% concentrated antifreeze:mad:. It's silicate free. i guess he knows sh*t about Hondas. is it ok just to drain all the current coolant and replace with Honda type II or it really needs to be flushed in order to put the new coolant in?
If it does need to be flushed, Could anyone here show me steps to do it right? thank you

05-29-2010, 02:07 AM
He doesn't know $h!t about automotive service!

05-29-2010, 03:04 AM
Assuming it's non-silicate, you haven't done any damage to the car. But pure coolant ****s at heat transfer, meaning the radiator could overheat in hot weather.

I'm sure others will chime in, but I strongly doubt that it is necessary to flush the non-silicate Prestone variety before adding Type II Honda. I would, but I'm extremely picky. I do think the Type II is better than the Prestone, it isn't just about corrosion and freeze protection; I've been told that the Type II is better for the radiator hoses and heater hoses over the long term.

Flushing just involves draining the bad coolant, adding water, running till the fans cycle a couple of times with the heater on max heat, and draining again. Then repeat until it looks like water is coming back out.

I am not sure if this V6 even has block drains; they're sometimes very hard to get to and if so, even most dealers will ignore that and just use the radiator drain although it is then an incomplete drain. I've never messed with draining my Accord coolant, although my Integra had a 2-inch wide block drain that a 19mm socket fit on. If you look around you might find something like that (one for each bank of the V6 I would assume). Or search this site. Block drain plugs are best wrapped with a few turns of teflon tape (from the plumbers area of the hardware store) for a good seal.

(The V6 has no air valve to help purge the air when refilling. So it's one less step to refill, but when some of the air naturally works its way out through the radiator cap/hose/bottle, you'll probably need to top off eventually, after several hot/cold cycles.)

It's not rocket science, but is a somewhat slow, messy process prone to getting you burned if you try to rush it or aren't careful.

05-29-2010, 05:33 AM
Prior to draining, turn key on, put heat setting to max, wait about 10 seconds and shut off.

The V6 has two block drains.
One in the rear with a 12 mm hex bolt that's the valve for the spigot. Look just above the right side axle shaft, you'll see it there.

The front block drain is the 19mm hex head large bolt, it'll be very tight. Look between the transmission and the front cat. This one will make a huge mess.
Put a small amount of either anti seize or teflon paste on the threads of this one. It has a large aluminum washer to seal it, so the threads don't need it for a seal. It just aids in removal later on.

I'd leave both drains open with the rad drain shut and just run water through the system, it'll pretty much push out the remains of the wrong stuff. Once the water stops running out there, reopen the rad, and drain out the water.

Do not under any circumstance drain water/coolant out of the car when it's hot.

05-29-2010, 05:59 AM
Why the heck are you doing anything? Take it back to the mechanic and have him correct his mistake or refund the money you paid him so you can pay someone else to do it.

05-29-2010, 11:36 AM
Thank you for all the input, guys! i'll do it sometimes next week, it's been raining for almost a week here in Seattle, and i dont have a garage:thumbsdow.

To baldeagle: i wish i could bring it back and have him corrected the problem. but he's a friend of mine, i just rather do it my self and not to bring my car back to him ever