Is It Time To Change Coolant

[Gemlin]

I have just bought a 2002 Corolla 1.6 Touring. Should I change the coolant considering that the car is over 4 years old? The car have a driving distance of only 20000 miles and been at service one time only (no coolant changed). If I should change coolant, how do you change it on a Corolla?

Greatful for your thoughts on this.

[TheSpannerMonkey]

A 2002 corolla will have long life coolant which should be changed at 40k or 4 years (if i remember correctly) so if it is 4 years old it is a good idea to even if it hasnt done 40k, because even though the coolant will probably still have the specified boiling temperature, it may have lost some of its anti corrosive properties

As i remember (tho i havent done one for a few weeks) the 2002 corolla has a rad cap on the rad rather than the expansion bottle so it should be a simple job, raise the front, drain the coolant out of the tap at the bottom of the rad (and be sure to do it up after as my first coolant change used 10 litres in a 4 litre system, opps), then fill it up with the same colour coolant (mixing the colours can apparantly lead to a chemical reaction that can corrode the inside of the rad), when it is filled up, check the level in the expansion tank, make sure the heater is set to hot (this is to ensure that the whole system is bleed) and start the engine, at this point i usually put a funnel in the opening in the rad, and fill it halfway as this allows for easy observation of the bubbles escaping from the rad, when the bubbles have stopped, remove the funnel and put the cap on, then run the engine for about 10 minutes (occasionally holding the engine at about 2500 revs helps) till the temperature guage reads about halfway, and both the large pipes from the rad are hot (as this shows that the thermastat has kicked in), i also tend to check that hot air comes out of the vents

and thats about it, i hope that helps and isnt confusing

[Gemlin]

Thanks, so you mean that opening the radiator drain will completely also drain the engine block. I shouldn't disconnect the a hose or loosen some plug on the engine to be sure all coolant is drained?

[nrgizerbunny]

draining the rad won't drain the engine block because the thermostat will be closed.

i would remove the thermostat and disconnect the bottom hose from the clips, this should drain pretty much all of the coolant out.

never heard anything about mixing coolant colours!

[Gemlin]

Ahaa!, but how do i remove the thermostat, the alternator seems to be in the way! do i really have to remove the alternator to remove the thermostat to remove all coolant? isn't there an easier way?

[TheSpannerMonkey]

you dont have to remove the thermostat if you dont want to and i would probably advise not as it is alot more work to do and will require resealing with silicon, technically there will be some coolant left in the system but this will only be a small amount and does not matter cause you are going to put in 4 or 5 litres of new coolant, also in the toyota workshop manual it says nothing about removing the thermostat for changing coolant

[Gemlin]

I have discovered a drain plug on the engine block (not easy to find). Let's hope that draining both the rad and the engine will get most of the 6.5L of old coolant out. I have read that one should flush the system using a garden hose but that requires that the thermostat is removed, so i will skip that. Has anyone really done that since stat removal isn't that easy on a Corolla?

Time to buy new coolent and get starting

[TheSpannerMonkey]

i never have, to be honest though with regular servicing it doesnt matter if there is still old coolant in the system when you fill it up cause it wont be enough to bring the new coolant under strength, makes it alot quicker and friendlier to leave the thermostat on

[nrgizerbunny]

i would definitely flush it out with a garden hose, you'll find corrosion from the rad in there, and that can't be good for the engine!

[Black Knight]

You'd probably have it originally filled with the green stuff I guess?

Only issue with mixing would be the new stuff is pink and a pink green mix would look revolting :)

Seriously it doesn't matter too much to mix in a little of the old coolant but better to drain the block using the drain bolt in the exhaust side of the block. Particularly since it's only loosening the centre hex of the drain bolt

[TheSpannerMonkey]

to be honest i thought it sounded a bit wierd that the green and red coolant mixing could corroded the rad, but its what they told me at the toyota academy so i thought i better say it, i wouldnt mix pink and green though cos in my experiance the pink is always extra longlife, and the green and red are longlife, but it may be different from other coolant manufacturers

i did have a word with a bloke at work, and he seems to think that the drain for the engine doesnt need the thermostat removed, it should be at the bottom of the bloke somewhere, though i didnt have time to look in the book for the exact place

[Gemlin]

The coolant is changed now. However I only got 4,5L of the old coolant out and I put in about the same volume new coolant (50% mix). But it should have been 6,5L according to the manual if the sysstem was completly drained. No sign of corrosion :).

Is it really possible to get all the old coolant out? Would a Toyota service have done in a another way? How do they do it?

[Black Knight]

to be honest i thought it sounded a bit wierd that the green and red coolant mixing could corroded the rad, but its what they told me at the toyota academy so i thought i better say it, i wouldnt mix pink and green though cos in my experiance the pink is always extra longlife, and the green and red are longlife, but it may be different from other coolant manufacturers

i did have a word with a bloke at work, and he seems to think that the drain for the engine doesnt need the thermostat removed, it should be at the bottom of the bloke somewhere, though i didnt have time to look in the book for the exact place

No, doesn't cause corrosion although I believe there's were concerns with precipitate blocking the heater unit.

You don't need to remove the thermostate. Look on the exhaust side of the block and you'll find the drain plug

[corollalover101]

good posts guys normally I just remove the drainplug at the bottom of the radiator and flush with a garden hose, don't know if my engine (5E-FE) has a drain plug on the block I wil check , the car came with the pink coolant but I replaced it with the Redline Water Wetter and distilled water, car is now running cooler