Engine and inverter transaxle coolant fluid change

If you were only charged for 1 gallon of SLLC, that was not enough to service both the engine and the inverter/transaxle coolant loops. The engine needs 6-7 US quarts for drain/fill and the inverter/transaxle needs 2-3 US quarts.

 

"BG COOLING SYS FLUSH UNITS"...

We really gotta get back to speaking plain English. Unintelligible, esoteric verbosity!

 

BG is an additive brand. Our dealership uses BG additives, notably their oil additive, containing molybdenum. I'm guessing they used one of their products to flush the cooling system.

BG Products, Inc.

 

1 gallon = 4 US quarts. Given the capacity Patrick listed in post #2 above:

The engine needs 6-7 US quarts for drain/fill and the inverter/transaxle needs 2-3 US quarts).​

I say they just did your inverter. They will use this free spare quart on another customer, and charge them for it too. If they did the engine cooling loop, they would be short 2-3 quarts, and you would actually hear this as you drive (sound of sloshing water sound, as the radiator is low).

 

Several possibilities:

1. The car was left in the dealer service parking lot and no service was actually performed.
2. The inverter/transaxle coolant was replaced, not the engine coolant.
3. The engine coolant was partially drained via the radiator drain cock, and ~3 quarts were added to replenish.
4. The engine coolant was drained by opening up all three drain cocks at the radiator, engine block, and coolant heat recovery canister, 6-7 quarts came out, new SLLC was used to refill, and you were not charged for the second gallon of SLLC. (The rated capacity is 9 US quarts but some fluid is trapped in the heater core plumbing.)

So if this is something that you actually care about, you will DIY in the future, so that you don't have to wonder which of these four possibilities actually happened.

I would say that in general, a engine coolant system "flush" is a bad idea because SLLC is premixed with distilled water, 50%/50%. The flush process will leave water in the system. Then when new SLLC is added, the overall mix will get below 50% antifreeze.

 

Hahah. This should be a poll. I pick #3. I don't see the dealer giving anything away for free. #1 is a possibility, but a huge liability.

 

I'm gearing up for a coolant change on an '06 Civic Hybrid, read through the instructions in the Service Manual. I've done coolant changes in various Accords over the years, and as far as I can see the drill hasn't changed a bit:

1. Drain radiator. (petcock at bottom)
2. Drain engine block. (drain bolt on block)
3. Open vent spigot and add pre-mixed coolant via radiator neck.
4. Once coolant starts coming out of vent, close it and continue adding coolant, till full.
5. Start car and let it run with radiator cap off and hood up
6. Stand by with a baster, as coolant bubbles/burps it'll rise a bit in the radiator neck. Baste it out into a container as needed to avoid spillage.
7. Continue till the radiator fans have cycled on/off twice.
8. Shut down, top up coolant in radiator neck, reinstall cap.
9. Drain, clean (as well as you can) refill (to full mark) and reinstall the overflow bottle.

Done. No electronic intervention, no need to run pumps. Plus just one circuit involved.

I guess the inverter circuit is a necessity with the Prius, but I read a lot about ongoing struggles to refill, rid the system of air pockets, etc. Is it that much tougher, and I wonder why? More circuitous plumbing?? I'll likely leave the Prius to the pros.

 

The 2G inverter coolant loop is not very hard to drain and refill. The Classic inverter coolant loop is fairly difficult.

The 2G engine coolant loop is relatively difficult to drain and refill if it is done correctly because of the need to refill the coolant heat recovery canister. I have previously posted on how to do that. I provided a workaround having to do with shorting the switched terminals of the CHRS pump relay. Of course if you have Mini VCI you can use that to run the CHRS pump via software command.

It also helps to use the yellow Lisle coolant funnel when refilling engine coolant because the fluid can be poured into the funnel so that the fluid level is a couple of inches higher than the radiator, thus providing more pressure for the fluid to move into the engine coolant passages. That funnel is a great device and there is no need to spill the fairly expensive SLLC when doing a coolant change, while using that funnel.

 

This device could be used in place of a baster and less spillage/waste.

This economy AirLift makes bleeding easy, not necessary any more. But you'll need an air compressor.

Here's a video of Carolyn @ Lusciou's Garage using an AirLift to fill the inverter then engine loop.

 

I'll add my vote for #3 on the list of possibilities.

I will also add my votes for (1) it's not that tough to do yourself, (2) doing it yourself you can be reasonably certain it was done right, and (3) use the advice and hints provided here by Patrick & others to make sure #2 applies. I just did my whole ICE cooling system including pump, thermostat, tensioner, belt, and hoses. Toughest part was the dang factory hose clamps, if that tells you anything.

And I can't see where this cooling system would benefit in the slightest from a "flush". Components and fluids lose their effectiveness, which is why we replace them at required intervals (in a perfect world LOL!) But a flush, IMHO, is totally unnecessary. Unless perhaps someone has added green antifreeze over time. But even then, I'd make darn sure everything was drained from the thermos, etc. before and/or in conjunction with a flushing chemical.

Edit to add: I'll also add my thumbs up for that Lisle funnel. It IS the bee's knees, so to speak.

 

The other major advantage is that use of funnel prevents air from entering.

Beatle: I suggest the following for an easy exchange:

• Buy the Lisle funnel (at Napa, eg.)
• Drain from the stop-cock and refill one gallon of SLLC using the funnel. No Air!
• Drive a month or two
• Repeat the drain and refill with one gallon SLLC