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Just did my first coolant replacement ever.

Gotta say I was surprised at how long it took for the air bubbles to stop coming out. They kept on coming up until the 3rd or 4th time the fan came on, and then after the coolant level went down, I just tightened the radiator cap and said the heck with it. After three (if not four) cycles with the fan, there couldn't be more air, could there?

OK my original question--I was also surprised at how much coolant dribbled out. Most of the time when I poured it out, I was careful to pour in only enough to raise the coolant level to the base of that neck (normally covered by the radiator cap). But it did expand, and bubble down. I suppose a towel is the only way to eliminate it dripping down. I thought paper towels would do it, but there was way more than could be contained by paper towels.

Finally my question: this coolant that dripped down--it isn't going to hurt the parts will it? Of course I will dry off with a paper towel the stuff, but its not like I need to wash the engine down with a lot of water is it?

 
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Sure.http://www.autozone.com/shop-and-gar...rd/255743_0_0/



Rinse everything off with a garden hose or a couple gallons of water.

 
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OK, I'll drive it to run an errand and back. As long as my heater is working and the temp gauge isn't going above normal, that means that there is either no air, or none that I need to try to bleed out, correct?

 
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I can't tell you that. I do know that system can trap quite a bit of air in the heater hoses......... and it can be dang tough to get it bled out without manipulating the hoses to work the air through, or maybe a few screaming redline RPM runs might get the water pump spinning fast enough to push the air lock through.

Hopefully several warmup and cooldown cycles will work out any remaining air.....






Test:
Hot engine.....Heater on full hot, fan on full blast: At idle RPM, is the air blowing out the vent hot enough to scald your hand?

Does the air temp get hotter when you rev the engine up to 3000?
If it gets a lot hotter when you rev up the engine, that indicates there is still an airlock trapped in the heater lines.

(this situation is very easy to notice when weather is very cold)

 
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OK, engine watered down. I'll run up the RPMs (88 degrees outside and rising, but that's what I get for being impatient) and report back when I'm done.

Oh wait. My civic doesn't have an RPM guage. I'll just rev it up till I hear it loud and clear.

EDIT: dial on left is temp guage only, middle is MPH, and right side is fuel guage.

 
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Air was so hot I had to pull my hand away. The needle didn't move above the halfway mark. Honestly I wasn't sure how to measure any air temperature increase after it already got that hot, so I can't say that at 3K RPMs or thereabouts, there is no air temp increase. But I'll keep an eye out on that gauge.

Thanks for your responses. Before the last year I never would have done something like this (change the coolant). I suppose a gallon of coolant is quite a bit cheaper than the cost of paying a mechanic to do all this. Probably paid for my rhino ramps with some spare change left over.

 
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I know I can feel a 15-20 degree change even when the air is already nearly scalding.....I just assume anyone else could also tell a difference LOL

In the winter cold it means the difference between having great heat or having pizz poor heat.

 
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OP... in my experience there is always tiny bubbles in the coolant system, it's the medium to large size bubbles that need to be bled out completely. Walmart sells this funnel: https://www.walmart.com/ip/FloTool-U...unnel/19888802 and you can detach the red extension and use the blue funnel to help avoid over-spill when bleeding the coolant. This bleeder funnel is even better: https://www.amazon.com/Lisle-24610-S.../dp/B001A4EAV0

As far as the overspilled coolant it's not much to worry about and when it dries you'll see whte spots on the hoses, frame, or other parts it came in contact with. When the engine is dead cold (overnight) wipe those areas down with a wet rag a few times. You may also see or more likely smell coolant burning off for a day or two so don't get too concerned.

When you bled the air from coolant did you have it on jackstands with the heater on max heat, recirculation mode, fan on high? Did you occassionally rev the engine to help purge air bubbles?

 
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Sorry I had the heater on max heat, but no fan on. The video I looked at didn't say to turn the fan on. Next time I should run the fan also? OK chalk this one up to experience.

No, I didn't rev the engine, that's probably why it took so long (15 mins at least) for the first time to get the rad fan to go on.

It was up on rhino ramps.

 
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Fan not necessary as long as it was on max heat.

Revs around 2500 to 3500 for about 20 seconds/intermittently helps.
Is you your heater working properly?

 
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OK, then I won't worry about turning on the fan next time.

Heater is working just fine. After the coolant change, I drove it and put it on max fan and max heat, and my hand could hardly stand to be right in front of the vents.

My civic doesn't have an RPM gauge, but next time I'll push the gas pedal for a bit, to get the fan to turn on quicker.

Honestly, not sure why I didn't do it this time. This was the first time I changed the coolant, and I couldn't stop staring at the engine, just looking at the coolant bubbling up out of the radiator. I think I was just glad that I didn't make the engine blow up.

 
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Nose in the air as high as safely possible. Not 100% necessary but on some designs every little thing helps.

Heater on HOT (for water valve to be wide open)-- but fan OFF.. The heater core is a small radiator, if you have it continuously removing heat from the cooling system you can delay the thermostat opening time significantly along with delaying the radiator fan indefinitely.

Elevated engine RPM, burning more fuel creates more heat faster, plus raising the water pump speed increases water pressure within the engine which can help purge trapped air through.
Mostly done just to speed up the warmup process and get the thermostat open quicker.
If I really want to purge air through I can take it to redline.

 
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Makes total sense. I didn't bother to dig into FSM for that info. IIRC some manufacturers state fan on and some off.

OP... which coolant brand, type, color (dye) did you use?
Did you drain the block's coolant jacket too?

 
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I ended up going with my mechanic on the coolant. He said green, I know nobody else likes it for the Honda, and I know that the green is not the same type as Honda type 2 blue (green is low silicate, but still a silicate; GHT2Blue is no silicate), but I'd still like to do coolant changes, and not flushes every time he changes the belts.

Anyways, I used the best green I could find, Valvoline Zerex Green. They gave a lot of specs for corrosion and other things, that no other coolant gave. Perhaps its all teh same, but I put my money with a brand that at least put more specs on its PDS.

No, not the engine block. I looked today and read that you'd only get another 2 cups or so of coolant, so I just decided to do this one step at a time, and only drain the radiator itself. My first time doing this. Maybe next time I'll drain the engine block too.

 
Rep Power: 210

Honda Type 2: http://www.worldpac.com/tagged/Coolant_-_Honda.pdf
Valvoline Zerex Green: http://content.valvoline.com/pdf/Zer...l_Bulletin.pdf

Coolants can get confusing so for the $10 difference from OEM to other brands/chemistry.. may as well go OEM and change it every 60k miles or so. Possibly, Ezone can shed some light on the subject.

Having done it I'd say that is a close estimate however, the important part is leaving the drain bolt off during a flush as it will help remove sediment lying on the bottom of the coolant jacket cavity.

 
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Forget the fact the stuff is poisonous, the most recent batch of gallons we received has extra warning labels stating the ingredients it contains cause cancer and birth defects in prisoners in California.




I don't notice sediment in the engines I take apart. I don't see lime and calcium buildup in radiator cores anymore. Hondas coolant seems to work great IMO.

 
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Right up there with the Zika virus...scary ****.

I noticed some sediment on the bottom of the coolant jacket a couple years ago when I had the cylinder head off. I guess that was old, dried gasket funk that I was seeing. I sucked it out with my good old Kirby vacuum and small diameter hose I rigged up.

Pentosin's Pentofrost seem to be very good products as well and stick closely to OEM formulas: http://www.pentosin.net/specsheets/P...st_spec_A3.pdf

 
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Wouldn't argue with that at all. I did consider taking this Civic to another mechanic who would use the proper coolant, but decided against it given my current mechanic's phenomenal track record with the 3 cars that I've taken to him. But if I ever move and need a new one, I'm switching the green out, that's for sure.

 
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Even though I usually do coolant flushes myself it's definitely one maintanence item that one would be justified to have performed by a mechanic. For the length of time between changes (5 years or more) compared to the cost (approx. $75 to $120) and avoiding the exposure to and disposal of it's worth hiring it out.

 
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I would say that a coolant flush is worth it, but given that my job allows me a ton of flexibility as to when I want to work and when I don't, and the fact that I have decided to take over maintaining fluids in my cars, I'll just do radiator drain and fills. Next time I might look at the engine block being drained or just do a flush; I'll surely do a flush if I get a new mechanic, and then I'll go to a silicate-free coolant. I take stuff to a local household hazardous waste facility 2-3x year so that isn't much of an issue for me.

 
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If a parts store sells you a hazardous fluid, don't they have to accept your old fluids for recycling?

 
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$20 to $25 a year (x 5 years). That's equivalent to one steak dinner per year.
I'd say it's very reasonable. Of course the flip side of that is if you do it yourself it's only the cost of the coolant: either 50/50 mix or undiluted and mix with distilled water (cheaper if coolant system takes more than a gallon).

 
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I don't know. Since I have to go out of my way to go to my local Napa parts store, and I need to go to hazardous waste anyways, I didn't bother to inquire if I could take the old stuff back.