Thread: D3 grunge in the coolant bottle

looks like the result of a failed oil cooler .

I did do a couple of paper "dip tests" and hadn't spotted oil or a film on the water.

Suppose I'd better order a cooler & gasket. I see the viable alternatives are genuine or Nissens. I've always had good luck with Nissens kit, is it worth paying > twice that for a genuine LR box?

Originally Posted by BradC

Last service (about ~8kkm ago) I did a coolant flush/replacement.

This was a drop and thorough rinse with tap water. Drop and fill with DI water, second drop and fill with DI water, then drop half fill with Penrite Blue (BLUE OEM COOLANT CONCENTRATE | Penrite Oil) and remainder with DI water. Each fill/drop was a full cooldown, dump, refill, run until thermostat open and properly warm.

Just had a look and found all this yellow grunge in the bottle. I can honestly say I've never seen that before in any car I've worked on. Anyone have any idea what it might be?

Hey mate, don't rush that oil cooler, it looks like silicate drop out, oil and water won't mix to make those solids. You will need to flush the system really well with a proper flush if you have that in there.
Itll block the radiator, oil cooler, heater.
I use Cummins restore plus, I'll have a quick read and see if it breaks down that crap.

https://www.cumminsfiltration.com/si...es/lt36625.pdf

From this I would use the Cummins restore, NOT the plus. Or just do both.

Make sure you get it up to temp and keep it there for the full time they tell you too or longer. Turn the heater on aswell.
You'll be shocked what drains out

Unless the previous owner has run a coolant containing silicates for too long (OEM, or Penrite blue is silicate free) I don't see how it could be silicate drop out.

Originally Posted by discorevy

Unless the previous owner has run a coolant containing silicates for too long (OEM, or Penrite blue is silicate free) I don't see how it could be silicate drop out.

That's what I can't figure out. I suppose it's possible, but it'd be several coolant changes and probably 10 years in the past.
I'll try and collect some of the powder and see what it looks like.

Originally Posted by discorevy

Unless the previous owner has run a coolant containing silicates for too long (OEM, or Penrite blue is silicate free) I don't see how it could be silicate drop out.

Yeah I agree, but it ain't oil in there.

For a few years people on here were putting in penrite red coolant because penrite incorrectly specified it.

Coolant has long been misunderstood and incorrectly poured in. More then any other fluid.

Either way. The Cummins restore will clean it out whether it's oil out drop out

Originally Posted by josh.huber

Yeah I agree, but it ain't oil in there.

For a few years people on here were putting in penrite red coolant because penrite incorrectly specified it.

Coolant has long been misunderstood and incorrectly poured in. More then any other fluid.

Either way. The Cummins restore will clean it out whether it's oil out drop out

Well, I don't suppose I've got anything to lose except $$ and time. If it's oil then it'll happen again and I'll change the cooler.