Plz help!! Got dark brown mud in my radiator...is it Dex-cool?

[freefallin]

Just came back from a 1400 km trip on my VY. When i got to my destination...i realized the engine is ticking. The ticking increases with the RPM. Like it gets faster with revs. A mechanic who lives nearby said it was the lifters. Prior to the trip i had thoroughly flushed the cooling system, drained all the water through the knock sensors and filled it up with 50/50 Dex-cool. No pellets were used. And i changed the oil and filter.

Today when i removed the rad cap, i found a muddy dark brown substance. And the oil is low, but that could be because i have a very small leak from the oil sump, but then again the leak is so small that it takes weeks for the oil to get low, im thinking maybe with the trip the leak increased, im not sure.

Anyway, what i would like to know now is if it is the Dex-cool that caused the sludge/mud and not a blown head gasket or inlet manifold. I heard Dex-cool does that. Thing is, i changed the head gaskets and inlet manifold gaskets about 3 months ago.

Can anyone confirm on Dex-cool?


P.s. There is no coolant in engine oil.

 

[Carl Blance]

The dark brown mud is oil, and I'm pretty sure oil cant mix with the coolant from the sump lol. It is leaking somewhere else it could be a rear main seal, I highly doubt you've done your head unless you didn't bleed it properly. I've never heard or used Dex-cool and anything I haven't heard of or recommended I won't use.

 

[BlackVXGTS]

I thought that the standard coolant on VY 3.8 V6s was an ethylene glycol (green) coolant. Dexcool®, a Propylene glycol (red) coolant is used in the LSx V8s and (I think) also the Alloytec V6s. Apparently it is difficult if not impossible to remove all the green coolant from a system. Mixing these coolants can cause contamination which dilutes their protection packages and can cause aluminium corrosion. Dexcool® has been known to cause head gasket and water pump failure on some Ford OHC V-8's. In addition, if you mix green and red together you will get brown, which is what you are observing. Having said that, I wouldn't have thought that the coolant was the reason for your ticking problem.

 

[lufkin]

my ecotec had dark brown sludge for a couple years, could never get rid of it, wasnt oil in water, just asif it was a rust or something, took it to a local mechanic and he said best thing to do would be a new radiator, so i bit the bullet and got a new one, havnt had sludge for years now

 

[freefallin]

Didnt have green coolant in the system prior to Dex-cool. Only distilled water.

 

[freefallin]

So is Dex-cool the wrong coolant to use on a VY V6??

 

[LordEthan2]

Is Dexcool red? i thought the red dex-cool was for the V8's