The Haynes for the '97-'01 is different from the manual for the '93-'96 Camry... the new Haynes says that to flush out the old coolant, you drain the radiator and engine block coolant, remove the thermostat, re-attach the thermostat housing, detach the UPPER hose from the radiator, turn the climate control to Hot (to flush the heater core), use a garden hose to force water into the top of the radiator, and collect the old coolant from the upper radiator hose into a bucket or basin until it runs clear. (Then drain everything again to get the tap-water out of the system, re-install the thermostat, and apply Toyota coolant plus distilled water.)
Question - does simply turning the climate control to Hot allow flushing of the heater core? Does the key have to be in the ignition / does it have to be set to ACC or ON to allow heater core flushing? The Haynes didn't elaborate on this point...
Unless your radiator is really dirty and plugged up, I would not suggest using flush chemicals and garden hose on it.
Normally, all you need to do is "drain and refill," with 50% distilled water and 50% concentrated factory red coolant. Or just 100% the new pink coolant with distilled water already added (good way to jack up the price).
Tap water has loads of minerals. And Toyota's coolant with phospheric acid rust inhibitor (or the pink organic acid), minerals will settle out of the coolant and plug things up fast. I wouldn't introduce any tap water into the system. But if you have to, I'd suggest flushing with distilled water afterwards. That is, running the engine with the system filled with distilled water for 3 minutes (all rad hoses connected of course and no garden hose here). Drain and refill two more times. After draining add the proper amount of coolant, accounting for the distilled water remaining in the engine block/radiator. (This is the standard VW method for changing from the old coolant to the new G12 coolant).
If you have electronic climate control, the key need to be ON for the motor to turn the heater valve to allow you to get to the heater core. But if you have the manual type, you don't need the key, just slide the temp selector to full heat. You should not run your engine at all with the garden hose method.
BTW, on the 4cyl it's not worth it to even touch the engine drain bolt. Little to none will come out.
Also, if your cooling system is in good working order, I would leave the thermostat until it's time to change the water pump (with the timing belt). Then you can do both at the same time.
Do check the radiator cap when changing coolant. If it is still the type with the hanging plastic vacuum valve, consider getting one with spring loaded metal valve ($7.99 at Kragen Prestone RR42). The plastic vacuum valve that allows the coolant to return from the reservoir is easily affected by contaminants and may not seal right. It's a poor design that nobody should be using these days.
Gotcha. The car has 67k miles on it, I got it from a dealer. I finally got a hold of an itemized list of what the mechanic had done prior to selling... it doesn't list a coolant changeout. I'm going to have to assume the car needs a coolant change. At least, though, it has pink coolant in the reservoir...
That's the bad thing about buying a used car from a dealer - citing "privacy concerns", the dealer can't release any records which has the previous owner's name on it...
Looking into your radiator will tell alot about its condition, if you see corosion on the fins a chemical flush is best, corosion means the coolant was neglected and is closing the radiators cooling ability. Im probably wrong about not running the motor when flushing with a hose.
Your method won't clean the radiator because water will come out of the drain plug at the bottom when it passes through the engine and returns to the radiator.
Make sure your brand of distilled water doesn't have "minierals added for taste." Or it'll defeat the whole purpose of using steam distilled water.
Letting water run out of the upper radiator opening will solve the problem, but you'll have water all over the place without another hose to guide it off safely. If any gets into your alternator or other electrical parts without drying up completely first, then those parts may be fried (BTW, you do know most alternators carry live battery voltage even when off, right?)
Or with the thermostat out (everything else in place including the gasket to prevent leaks) you can fill up with distilled water and run the engine for a minute (before it warms up, so you don't add cold water to a hot aluminum engine). Repeat a couple more times. The water should be pretty clean by the 3rd or 4th time.
It's a lot of extra work if you have a pristine cooling system. I "drain and refill" every year to year-and-a-half so everything looks nice and clean. Be sure to account for the extra distilled water left in the system and adjust the amount of concentrated coolant accordingly. Use total system capacity as a guide in calculating how much concentrated coolant to pour in.
Note: if you can only get pre-dilluted coolant (like the toyota pink, not toyota red) in your area, then the recommended procedure is to use the pre-dilluted coolant to "flush" your system as if you're using distilled water!! (It must be an accountant who came up with that idea). Otherwise you would be left with less than 50% concentration, which is not good at all for the aluminum. The pink organic acid coolant is pre-dilluted with 50% distilled water so the grease monkeys at the dealer can't get it wrong or trying to get by on the cheap with tap water, because organic acid coolants don't really like tap water. So look before you add water to the coolant, it may be pre-dilluted.
Check where the cooling tubes are welded to the header plates when you look into the filler neck. Make sure the solder isn't corroded and begins to "bloom". Modine Radiator used to have nice pictures on their web site to tell you about what to look for, but now they merged with Transpro to form Proliance and the pictures are gone.
The Haynes manual says to remove top radiator hose and thermostat, and flush with a garden hose while engine is off.
The instructions on the Toyota coolant say run engine while draining the radiator and filling the radiator with water.
Neither of these directions mentioned using distilled water. Oh well...
I followed the directions on the Toyota coolant - less invasive. Maybe wasn't the best idea... thermostat might not have gotten up to temperature with cold water circulating in the radiator... I'll try the Haynes next time.
The Toyota coolant container's method is a standard "refill" procedure, after you "drain". It simply allows all the air to collect back at the radiator so you can add more coolant to fill it up.Some cars also require you to open purge ports at high points on the engine.
As far as the labeling goes, I have to look again. It might have said demineralized water or something like that being recommended. But for the health of any cooling system, don't use anything other than distilled water. For example, Modine radiator's lifetime warranty is voided if tap water is added to the coolant.
The Haynes manual is fine if your radiator/cooling system is plugged up with lime scale and deposits.Then you should do that method, but make sure to use an acid-free cleaner compatible with aluminum parts and not just any clean designed for iron blocks. By the time you get here, it's more like a cooling system repair.
If the cooling system is pristine, "drain and refill" is sufficient.
You may be interested in the article on "flushing" the rad:
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The "Radiator Failures" tab has pictures of solder bloom. Or if you see white deposits on the inside of the plastic tank then there is steam damage and the plastic tank may be going, etc.
The "Radiator Installation" tab kinda tells you how to "refill" after putting in a new rad, etc, etc.
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