Transmission Flush and Coolant Flush

[DrivingHabit]

Whens do you guys usually get a transmission flush and coolant flush done at how many miles?? I'm getting close to 20,000 miles.

[lain]

When your car starts to give signs that it needs one...like overheating. Other then that there is no reason to ever get it unless you just like to spend money...

[kc5f]

For coolant, the service manual states: After 60,000 miles (96,000 km) or 48 months, replace every 30,000 miles (48,000 km) or 24 months.

For transmission, it says to inspect every 15k miles and replace as necessary. For the CVT it adds this note: If towing a trailer, using a camper or a car-top carrier, or driving on rough or muddy roads, inspect CVT fluid deterioration with CONSULT-II every 60,000 miles (96,000 km), then change CVT fluid NS-2 if necessary. If CONSULT-II is not available, change (not just inspect) CVT fluid NS-2 every 60,000 miles (96,000 km).

[Ever Victorious]

Typically I've drained and refilled (not FLUSHED) ATF in my other cars every 30,000 or so miles. I've noticed that after that mileage, transmissions tend to start slipping a bit. As for a power flush (complete fluid replacement), I did that ever 100,000 on an automatic. The only exception to this was a 1st gen Legacy wagon, because they had known issues with ATF filtration problems, so the intervals were half as long.

As far as coolant, I tend to flush and refill every 30,000 miles. Historically, I have owned only cars that use old, basic ethylene glycol based coolants that don't last much longer than this. Some newer cars have longer intervals because they use newer styles of coolants that last longer. It is important that you replace your coolant with the same type that came with it, to prevent a chemical reaction in your system (i.e. if you use ethylene glycol, do NOT replace it with CoolDex!)

Edit: do NOT follow Lain's advice of waiting till you get an indication of overheating before you change your coolant. Since the Versa does not have an analog temperature gauge, you can't tell when it's "starting" to overheat. Your only warning of an overheat condition will be a red indicator on the dashboard... and by the time that happens, your engine is ALREADY overheated. Say hello to a blown headgasket and, if you're not lucky, a cracked head and/or warped valves. Tell me which is more expensive: $50 (worst case scenario, paying a mechanic) to have your coolant changed every 30k miles, or $1500+ (depending on timing, availability and labor) to replace your engine?

[lain]

I've driving many cars that have overheating problems...they don't blow that fast...maybe i was just lucky.

[biggie]

I've driving many cars that have overheating problems...they don't blow that fast...maybe i was just lucky.

Amazing since a 240 will blow a HG as soon as the stock temp sensore reads 'H'.

And yeah, you want to do both things ever so often. On AT flushes I usually go 75k miles or so, depending on conditions. And you should just be checking your coolant/antifreeze before each season to make sure its ok, then I'd say flush it every 50-75k, your decision.

[Ever Victorious]

I've driving many cars that have overheating problems...they don't blow that fast...maybe i was just lucky.

On a car with a true ANALOG gauge, you have some leeway as the temperature rises from its normal operating temperature.

I can think of a car that has an "analog" (not really) gauge that doesn't do this... an '88+ RX-7. The temp gauge has three readings... "Cold", "Normal", and "Replace Engine".

Essentially, that's the system that our Versa has.Blue = Cold. No light = Normal. Red = Engine is fried.

Now, if you install a water temp gauge and monitor it, you will once again get that leeway and have some warning before the temp goes too high. But again, it's just cheaper and simpler to change the fluid preemptively.

I have FULLY overheated 5 cars in my life. 3 survived to tell the tale, and all 3 of those were water-cooled engines that were Subaru derivatives of the original air-cooled Beetle engine. I wouldn't do that to a modern Subaru, because if you look at it funny, it will blow a head gasket.

[sooner4x4]

For the transmission (auto/CVT) the Service and Maintenance guide recommends every 30k if you are following the "Premium Service" schedule or never if you follow Schedule 1 or 2.

While a lot of the stuff recommended in the Premium Service schedule is a load of crap, changing out the transmission fluid every 30k is good practice if you plan on keeping the car any length of time.

When I was a little younger and cars were a little simpler, I did quite a bit of my own maintenance, including changing the auto transmission fluid. The last car I regularly did my own ATF fluid changes on was a 1991 Dodge Spirit purchased new. This is what I observed with the fluid condition on the three changes I did on that car. On the Dodge, you had to drop the pan which gave you access to the filter and a magnet. I replaced the filter each time.

At the first transmission fluid change at 30k miles, the magnet had a bunch of very fine fuzzy magnetic particles on it, and the fluid was quite a bit darker than new fluid.At 60k I did the second fluid change, this time the magnet had much less fuzzy magnetic particles and the fluid was not as dark as the first time. At 90k, I did the third fluid change, no fuzzy material on the magnet and the fluid looked almost like new. I vowed not to change the fluid any more, but at 100k the car was totalled in a wreck.

Draw your own conclusions. But from what I have personally observed, getting that first couple of transmission fluid changes done at 30k intervals gets most all of the wear metals out of the transmission and keeps your fluid in good shape. It doesn't cost that much and helps assure long term trouble free performance from an expensive to replace item.

For the coolant; the schedule 1 or 2 in the book recommends a reasonable change interval, as described in a previous post.