Thread: D3 grunge in the coolant bottle

Originally Posted by josh.huber

Must have really had some **** in it for that flush not to get it out in that drive.. did you have the heaters on for the drive.

When you look at the D3/4 cooling system, the heater matrix is almost like a sump, with a long fall/climb for solids to get in/out. Given it's parallel flow with the inlet and outlet on the same end, the passenger end just progressively fills up with grunge and there's not enough pressure differential to push it out. Combine that with the fact it almost never gets isolated and flushed itself, it just acts like a filter and holds the grunge. I've noticed a similar thing with the bottom fuel cooler plate heat exchanger. Every time I give than an individual blast a whole heap of crud comes out.

I know I don't really need to flush with DI water, but I've always used a DI flush after a thorough hose through. At less than $1/L at the green shed it's not particularly onerous and I put in the box with "can't hurt".

I'm astonished at how little residual remains in the system after a blow through. I think the key is making sure the heater is clear, but each time I've filled it it's taken ~11L.

Do you have rear AC Brad? That just adds to the fun. My bottle has started to get brown stuff in it. I suspect it’s time mine was properly done, but I just can’t bring myself to. It’s such a crap job

Originally Posted by DiscoJeffster

Do you have rear AC Brad? That just adds to the fun. My bottle has started to get brown stuff in it. I suspect it’s time mine was properly done, but I just can’t bring myself to. It’s such a crap job

No rear AC thankfully, although now knowing how to isolate the heaters it's not actually that terrible. At least there's no heater valves, so it doesn't matter whether the heat is on or off, or the engine is running or not.

I'm floored at the amount of crud that flush brought out, but crikey the flush itself isn't easy to get out either. It'll be interesting to see if Penrite respond about the colour loss.

Brad at those rates I'd happily use the demin water, i home brew and looked at it once to see if the town water was affecting the brew. The price wasn't great $2 a litre.
And on 23litres I could buy commerical beer.
If your using concentrated coolant then demin water first is the go.

Glad to see you got most out. The colour does disappear quickly with corrosion etc..
I suspect they will blame the non brand coolant flush. Either that or their addictive pack attacked the corrosion in the system and was affected by that.

Im currently testing a caterpillar "slow cleaner" which you add to coolant and forget for a few months. If it comes up good I'll let you know. The benefit is boil, freeze and corrosion protection during the clean. I need to do more research to see if it's for drop out or rust and scale. I suspect rust and scale.

The Cummins restore for rust cleaned out my bottle. But the bottles are cheap.

With what you have done. The blue coolant should stay blue for a while..

PS I love that you taste tested the flush. That's how I tell that it's out too. In Lucky my boat has block drains right at the bottom makes cleaning it a dream.

Right, it's all back together and the coolant is a nice clear pretty blue. Now we wait. At least I have heat on the passenger side, just in time for summer.

Originally Posted by josh.huber

If your using concentrated coolant then demin water first is the go.

I've always used concentrated coolant. On most vehicles I find there's always residual water in non-trivial quantities, so my making all the flushes demin then I can drain with "best effort" and put exactly the right quantity of concentrate in, then top up with demin for the remainder. That way the concentration is always right.

Originally Posted by josh.huber

Glad to see you got most out. The colour does disappear quickly with corrosion etc..
I suspect they will blame the non brand coolant flush. Either that or their addictive pack attacked the corrosion in the system and was affected by that.

Actually, I used their flush and did it exactly as per directions, so there shouldn't be any issue with that. I'm not particularly convinced of the effectiveness of a "7 minute flush", but it's their product and directions. Interesting that I've never seen a coolant of any type lose its colour before. I can see how it might happen though.

Originally Posted by josh.huber

PS I love that you taste tested the flush. That's how I tell that it's out too.

I saw you mention that earlier in the thread, so I added that in after the pH test. Made sense.

Edit: Oh yeah, when replacing the coolant bottle don't wait until it's all buttoned up and you are on the test drive to remember you forgot to put the coolant level sensor back in the bottom of the bottle.

Interesting posts, thanks.

I did a flush at 80k and 140k and replaced with Blue.

It’s still bright blue now and no sediment.

I’m as OCD as the next bloke but I find the concern over leaving a trace of flush in the system hard to understand. If you add one of those <1 litre miracle wonderflush bottles to the full system (which all say can’t hurt anything while wonderfully removing rust and goop) then drop it you are left with some tiny amount left at the small original concentration (5-10%). Then if you do a flush DI fill run it and drop it (as well as blowing out etc.) you have an even tinier % left in whatever fluid remains in the system. You then fill again with your new coolant and the % is again reduced. Let’s say of the original 600ml of flush fluid there’s 20ml left within the 10-11 litres of new coolant.

It just seems an incredible amount of effort for a tiny tiny improvement and for sure no auto shop in the history of automobiles will have done more than one flush if at all?

I have a new overflow bottle and oil cooler & gasket soon to tackle that job and associated coolant refill.

Originally Posted by PerthDisco

I’m as OCD as the next bloke but I find the concern over leaving a trace of flush in the system hard to understand.

It wasn't so much the trace of flush, but the inches of Guinness style head in the coolant bottle after the flush. This stuff is much stronger and far more tenacious than any "wonder flush" I've used before, so much so I wonder if the "parts store" flushes are much more than coloured water. Had I not kept seeing a huge amount of fine foam in the coolant bottle after each run I probably would have just left it after the first rinse, but as I had the time, tools and water I thought I'd see if I could get as much out as possible.

Remember this whole mess was likely caused by an inadequate flush leading to a reaction between coolants resulting in plugging the heater matrix. Not wanting to risk plugging the oil or fuel coolers, and being ultra careful as a result I just wanted to go the extra mile to make sure it was done as thoroughly as time allowed.