question regarding a coolant system issue

[4xcrazy]

Here's the the thing, i have owned nothing but Chevys after the first Datsun i owned, so i can find my way around, work on and do some serious repairs and for the most part get diagnosis of problems fingered out, but this one is just got me curious.

I'm not all too concerned with it, as it's not affecting the cooling capabilities of the motor, it's just annoying to me, mainly cause i like to keep the fluids clean in my rides.

THE ISSUE:

When checking the coolant level in the '94 pick-up, 4.3ltr Vortec V-6 223,800 miles (all original) the coolant looks clean and the color it's suppose to be, but there is usually this brown sludge crap building up all around on the radiator cap, and the rim of the fill neck.

I have flushed this system out several times since i/we have owned it, and am pretty sure i got at least 80% of all old coolant/water out and had nothing but clear water coming out when flushed, then added the recommended mixture for the climate conditions at the time, usually 50/50, and all is good for a few more months, until i just now, again checked the level, and more of this "mud" was accumulated. Not nearly as much as in previous times, but still there.

Thinkin maybe previous owners dropped some Barrs Leaks or some crap in there for some reason, not sure though.

Any ideas?

 

[sweetk30]

first off reg gren or dex cool ?

if dex cool GET RIDE OF IT !!!!!!

if green then problem.

what vortec 4.3 ? there is basic style tbi or full mpfi vortec with plastic intake gaskets. thay are known for breaking from age.

are you getting brown sludge in the engine oil on the dip stick ? if so you got a intake gasket leak problem. most wont leak external but inside the engine and fill the crank and cause major problems.

let us know from there.

 

[4xcrazy]

I have already replaced the intake gaskets a few years ago, develpoed a small leak up near the front of the water passage to the head.

It's an earlier Vortec with aluminum TBI intake, and using green coolant, never liked what the Dex-cool lookedlike after a few thousand miles or less.

Nothing in the oil, motor doesn't even use any between oil changes, doesn't smoke, doesn't leak,,, damn good running motor still.

Also have replaced the radiator twice in the past 3 years, both had the plastic tank with aluminum core/fins.