danfil

Previously my vehicle when purchased had green coolant in the system. This has cause massive headaches for me as again I need now to replace the coolant fan sensor switch and the sensor for the temp gauge. I have received the parts from the U.S. and am going to install tomorrow.

My 2.6 e V6 ABC motor has a drain plug at the rear of the motor underneath and as in previous acid free flushes and screw driver attempts nothing has come out after removal of this plug.

So before the heat in Aus really vamps up I was going to try a acidic based coolant flush. The one is a Techloy HD2 version and clearly states acidic where as most of the other brands are non acidic. I am not sure if you get these brands in the U.S. 'Rusty' but am eager to hear your opinion on using such on this V6. I know these motors are finiky at best and am using the correct coolant.

Just need to know if it is safe to use the acid flush in the car as to remove more rust from the system than before when I flushed.


Dan.

Rusty Spokes

On my 12v V6 engines when i found rust (happens often) I would remove that plug under the engine and use a garden hose to flush out the block.

When you remove that allen bolts..you may need to use some wire or a screw driver and probe the drain to get the rust opened up to flow. That area is a designed "trap" to collect rust..so it can be deep in there.

I am reluctant to use acid or citrus washes ..plain old H2O seems work fine without damaging the water pump.

Just flush, engine off, till all the water coming out is clear.

Be sure your heater is working..the rust will plug up the heater core..if your heater is working then just flush with water.

CRAZY_RUSSIAN

2nd on Rusty's comments
i usually pop all the hoses off and flush them with garden hose in opposite directions
and you may want too look up the o-ring that goes around that engine block drain plug. i know somewhere on here there were dimensions for a viton o-ring.

uberwgn

I believe you can still buy the citric acid flush powder from MBz. People seem to have limited success with it meaning it can cause leaks.

grillage

For the block drain:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

IdahoDoug

Just an FYI, green coolant is fine in your block. I don't want others to get the impression that green coolant is the problem - it was likely lack of proper flushing during the previous life of the car.

I have heard things like that before, but any coolant designed for engines with aluminum and other metals (virtually all of them) will do fine. A final comment is that the "long life" coolants are great stuff, but don't leave them in forever. Coolants lose their additives, accumulate wear particles, and undergo chemical aging faster in our older engines than in a new one from the factory they were designed for. I am a big advocate of using cheaper coolant and regular flushes, vs crazy hyper expensive German violet colored coolant that "your Audi has to have". Cough.

CRAZY_RUSSIAN

as long as you don't mix green (or whatever color) with the G11/12/13 you are fine.
i usually flush my cars every 2 years with factory recommended coolant and call it a day