How To: Flush Coolant System, and Change Thermostat. (56K=No way)

[.Ry]

Well ladies and gentleman this is my first DIY, so please bare with me. This is how I do this job, you may have other ways. Might as well get this out of the way first. Do the following at your own risk, I am no way liable for you screwing this up. Ok lets get started. Make sure your Engine is cold, makes it easier to work on and less chance to crack the block with cold water. The engine is a D16Y8 on a 97 Civic EX. First these are the things you will need. Various extensions, sockets, wrenches, new thermostat and rubber gasket. Also some coolant. I bought mine pre-mixed at 50/50. I bought four because I didnt know how much I would need. Now, drain the radiator by taking out this wing nut drain bolt on the bottom of the radiator. Have a drain pan ready! I could not take a picture of this but on the back side of the block by the oil filter is the drain bolt for the cooling system. Remove this plug with a 19mm socket and ratchet. Becareful because you will get soaked. Snug it up because you will remove it again later. Take of the lower hose clamp, I used a pair of vice grips. I took my CAI off for more room, I think its easier. Now we get a good look at where the Thermostat sits. There are two bolts holding the cover in place, and they are 10mm. One is easy the other is a PITA!! There is also a ground wire there as well dont take it off, no reason to Next take off the the clamp to get the hose loose. Its been awhile for these, so it took some effort. Once you get the hose off lay it aside and this is what it should look like. The circled part is your Engine Coolant Tempature Switch or ECT. Now its time to get the cover off. For the bolt thats the PITA, I used an extenstion. Now it has to go through the spot I have it at. I could not find any other place to get a socket/ratchet to. You could use a 10mm wrench but it would take so long! Use the extension for the top bolt as well. I had to pry a lil bit to get the cover off, but once you do you should see this. Now here you cant see it but that lil cut off of the rubber seal has to go back the same way. On the thermostat there is a lil bobble pin that goes straight up. Now pull out the thermostat and you should get a nice push of water coming out. Reason being the thermostat is closed till its get warm like 180 degrees. Here is a pic with the thermostat removed. Now take off the clamp to the upper radiator, block end. Now the flush. Everyone has there own way, but here is mine. Normally I would stick the garden hose into the block as shown. I would have liked to used the lower radiator hose so water wouldnt get over the block. But in order to do that I would have to have put the thermostat cover back on tight. Since the bolt was a PITA, I left it alone, and let the water go out that way. Make sure your climate controll is set to HOT. Nice and Clean!! Let the water run for about 4-5 minutes or so. When done flush out the raditor. Also be sure to remove the drain bolt on the back of the block, left of the oil filter. When the water drains out go ahead and lock it down. Time to reassemble. When done flushing, put in the new thermostat and replace the cover. Goes back on the same way. Put all the hoses back on, with their clamps. No pics should be straight forward. You should use new hoses and clamps but mine were in good shape so I didnt bother. Also replace the drain plug on the radiator. Take out the Coolant overflow tank, and clean it out. Then put it back in. Everything put back together. Top off the tank and radiator with 50% antifreeze and 50% water. Mine was already pre-mixed. Now start the car and let the engine get to normal temp. Add mixture as neccasary. Here is the coolant getting a lil hot. Looks good after 20 minutes of run time. Now the problem is that it got dark so I wasnt able to add enough coolant I think. My helms said 4.2 liters of liquid needed for the system. So far I have only used one bottle of the 50/50 mix, which is like 4.4 or something. Reguardless add untill no more bubbles come out of the top. I will have to double check the level tommorow after I drive around to make sure its ok. Thats it. I hope I didnt leave to much out, but I tried my best. Please leave ANY comments, tips, rants, remarks you want. Note: PLEASE DISPOSE OF ALL OLD COOLANT IN A DESIGNATED PLACE BECAUSE I LOVE MY ANIMALS.. Modified by turner7205 at 2:19 PM 11/6/2005 Modified by .Ry at 2:32 PM 10/20/2007

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[fizeks]

good write up

[Aquafina_Powered]

[RCautoworks]

Good job

[.Ry]

Thanks so far guys.

[Slow EJ8]

Nice write up man. I see your getting alot of matinence items out of the way before winter.

This is a good reminder for me too, I should do this to mine (have no clue when it was done last, got the car a year ago).

[.Ry]

Since we have the same motor should be the same deal lol. Took it for a drive, upper rad hose is hot, the lower one is not hot. Ive searched and it seems that when its cold, and the heat is on its supposed to be cooler.

[EG2Driver]

dammit! WIsh i woulda known how to flush everything out with the garden hose....just did mine last weekend. NOt hard at all. I thinks its easier than doing brake pads. Good write upm by the way

[.Ry]

Ive used this method before, and had good results.

[REAL TIME]

[Slow EJ8]

good write up bump

[ecahatch]

Originally Posted by fizeks

good write up

[CardDealer]

Modified by CardDealer at 3:18 PM 11/16/2006

[wutupnut]

Very nice.

[raiden571]

i would have used orange fluid, i think its called dextal, better for aluminum blocks/radiators

[Frozen E]

Originally Posted by schlit

Nice write up..

If you have hard tap water, do you think you're leaving minerals in your system by doing the flush? Where I live, the tap water will leave a serious amount of minerals behind when it evaporates.

He used the pre-mixed stuff. Also, there's no reason your coolant should be evaporating. If it is, you've got bigger problems.

[Jonzo]

He means the WATER evaporating, you jackass.

[92ehatch]

he means like if i was to takke my dirty ass well water and run it through the system it mould leave minerals and dirt particles

[dogbiscuit]

yeah, if your changing your Water Temperature sensor or guage sensor i would recommend draining your whole system. i didn't for my car and when i pulled the sensor i had water bellow out of the cold block for about 2 minutes. i should have went ahead and done this maintainance.

[postman]

you did a decent write up, but the flushing thing doesnt really work. all you did was run water through your system. technicall inorder to flush the system clean to actually help remove particles inside, you need bg flusher kit which is an expensive machine , but uses solutions and filter to push particles out. you would be surprised what the hell comes out of it when your done. shit water eould never get. still good wite up

[96CivicBoostCoupe]

nice simple service write up

[RCautoworks]

Originally Posted by raiden571

i would have used orange fluid, i think its called dextal, better for aluminum blocks/radiators

You just better make sure you get every last drop of green coolant out. Green and orange coolant does not mix well.

[violence_hero]

Originally Posted by postman

you did a decent write up, but the flushing thing doesnt really work. all you did was run water through your system. technicall inorder to flush the system clean to actually help remove particles inside, you need bg flusher kit which is an expensive machine , but uses solutions and filter to push particles out. you would be surprised what the hell comes out of it when your done. shit water eould never get. still good wite up

I'd have to disagree with that. On an older car you'll get plenty of crap to come out with a garden hose. And the pressure of a garden hose is actually pretty decent if you think about it. It would definitely help to hook up the hose backwards in relation to the normal coolant flow of course.
The professional stuff? I've had it done once and wasn't very impressed. In fact, I think it's a bit risky because the pressures are HUGE. And I mean coolant leaking from NEW heater hose connections huge. Then again the people who did it to my car could have been gimps, who knows.

[portuflip]

thumbs up!

[VTAC-KAT]

Originally Posted by schlit

If you have hard tap water, do you think you're leaving minerals in your system by doing the flush? Where I live, the tap water will leave a serious amount ofminerals behind when it evaporates.

Poland Spring