anti freeze

I checked my antifreeze on sunday and found a brunish crude around the cap and in the top of the radiator. what is this crude and how much of a problem can it cause ???? if I need to flush the system what is the best flush on the market ?? oh it's a 2000 impala with the 3.8 engine. thanks

if coolant has'nt been changed in the last couple of years then it could
be the dex-cool(anti-freeze)thats sludging.drain & flush system maybe
a couple times to get system cleaned.if left unmaintained it will corrode
parts ie.rad,heater core,gaskets

The chocolate crud is what appears when oil mixes with the antifreeze. It is very likely you have a upper or lower intake manifold gasket leaking. This is a very common issue with the 3800 series engine.

You can flush it, but if the crud returns, you need to have the gasket changed.
Take it to a mechanic you trust and get him to look at it to confirm.

I checked my antifreeze on sunday and found a brunish crude around the cap and in the top of the radiator. what is this crude and how much of a problem can it cause ???? if I need to flush the system what is the best flush on the market ?? oh it's a 2000 impala with the 3.8 engine. thanks


if the brown crud is growing on the internal radiator this would be dexcool reaction with dirty water[drinking water] and or silicate coolants [ compatible coolants] dexcool is dexcool. no GM logo on container it is not dexcool..donot allow anyone to add fluids to your vehicle they will cost you big ! only distilled water..60% dexcool to 40% distilled water.

pressure test also , for any coolant gaskets/head gasket failures..must pressure test and hold 15 psi ...the coolant system..

the best coolant system cleaner is acid cleaner with the baking soda rinse. this is heavy duty and if done properly will clean out the coolant system..dont forget to flush out the heatercore..alot of debris traped in there.

flush it with CLR it works way better than those flushs sold at autozone or autoparts store