Oil in Coolant Reserve

[TigerVX]

I appear to have a brown oily substance in my coolant reserve. I only notice it on the coolant dipstick as just a thin film. There is no sign of emulsified oil on either the coolant or engine oil dipsticks or in the engine oil cap. No loss of oil or coolant either. There is no sign of oil in the radiator and if I put the coolant dipstick back in after cleaning it there is no sign of any more brown crap. Coolant is new also.
Anyone know what this problem might be?
Cheers.

[clixanup]

V8 or V6?

Many coolants are oily in texture anyhow. Did you change it yourself or did a workshop do it? The brown substance may be from deposits in your engine or heater core if it they weren't flushed properly.

What would I do? Drive it around for a few more weeks, but keep an eye on the dipstick and watch for excessive steam from the exhaust.

[WAGON MAN]

It may just be the cooling system pellets that Holden recommends you install in the lower radiator hose when replacing the coolant.

The pellets turn the coolant slightly brown from the normal green colour.

[lumina01]

I got the same thing in mine, was freaking out coz my car was overheating then when i checked the dipstick tiny lumps of that brown shit.
I'd say it was due for a good flushing, probly just old coolent.

[TigerVX]

It's a V6 and I changed the coolant about 6000km ago.
The cooling system including heater core was flushed out really well and I didn't put the pellets in.

[clixanup]

The cooling system including heater core was flushed out really well

Are you 100% sure of that? Did you remove the thermostat & heater tap before flushing?

[hsvpgts]

It is normal for the overflow bottle dipstick to show signs of sludge. When working at d/ship I never saw another person remove overflow bottle to clean out when doing coolant flush. Remove bottle yourself and clean/rinse out with hot water (easier to get rid of sludge with hot water) then refit and refil with coolnt. No need to bleed bottle as only recovery bottle.

[minux]

lol, check your transmission fluid and make sure it isnt bright pink

Sounds like you have a ruptured oil cooling line for the transmission that runs through the lower tank of your radiator(another completely pathetic design by holden).

I'd just keep an eye on it even if your coolant has changed color. If this has happened, your engine will need to be pulled down and you will need a new gearbox.

[TigerVX]

The auto trans was my first concern but there is no sign of water in the trans oil.
System was washed thoroughly inluding heater core and thermostat was changed.
Coolant reserve bottle was removed from vehichle and cleaned out too.

[VTPREDATOR]

sounds normal too me. theres always some sort of brown **** on the stick in every vt/vx ive seen

[accentstencil]

Yep, I get it too especially on the radiator cap.

[TigerVX]

Cool thanks guys.