A friend of mine just bought an 85 Trans Am lg4. He's changed the fluid in it 3 times and each time he does it, when he drives it for a day or so, it turns this nasty light brown color. He flushed the whole system and everything but it's still doing it. What is causing this????

Thanks for your help.


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My 1986 Z28
GM350, T-5, 3.23's, lots of go fast goodies, 4th gen Firebird interior etc...
85 IROC w/ 1364 miles!

You'll always find what you've lost in the last place you look

R.I.P Dale Earnhardt

I guess he has a lot of built up rust in there. His only hope is to do a full back flush (get one of those kits that hook into the heater hose), then run around for a while with some of those cleaning/descaling chemicals in there, then flush it again, and make sure he uses a quality AF.
...ed

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Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

another possibilty is that tranny fluid is mixing w/ the fluid. if the tranny is shifting okay, probably the built-up rust mentioned earlier.

Its a T-5, so the tranny fluid pretty much stays in house. Theres no cooler or anything.

He's already flushed the system twice through the heater hoses, but i'll tell him to try running it with the chemical in it for a while, and then we'll flush it again.

thanks,
Eric

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My 1986 Z28
GM350, T-5, 3.23's, lots of go fast goodies, 4th gen Firebird interior etc...
85 IROC w/ 1364 miles!

You'll always find what you've lost in the last place you look

R.I.P Dale Earnhardt

I had a '79 Z-28 like that. He will NEVER get rid of that brown. Don't know what causes it. Don't know what cures it. But there wasn't anything leaking into the fluid (xmission fluid, oil, etc.)

The problem is when there is a lot of rust in the system, it all settles in the lower portion of the block, out of the coolant flow.

When you add new stuff, it settles into the old crust in the bottom of the block and turns brown.

I've pulled freeze plugs out and had the rusty crust so thick the water wouldn't drain out of the block. I had to scoop it out with a screwdriver

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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

[This message has been edited by Engineboy (edited June 13, 2001).]

My sister has a f-150 and does the same thing.
Her engine is rebulit so I think that the rad might be rusty inside,and it tends to run hot sometimes.
Another possibility is that someone put rad stop leak in a few times and it's starting to come out.

Alright so we know a few possibilities of the causes of it, and we know a few ways to fix it, but in all honesty, is it really a problem? The car doesn't overheat unless its idling for long periods of time in 90 degree+ weather, so should we even bother trying to rid the car of the problem?

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My 1986 Z28
GM350, T-5, 3.23's, lots of go fast goodies, 4th gen Firebird interior etc...
85 IROC w/ 1364 miles!

You'll always find what you've lost in the last place you look

R.I.P Dale Earnhardt

Heres how I got rid of it in my car..

I tool off the thermostat housing and shoved a garden hose down there. then open up the radiator, start the car and let the water run through the block. It took me 2 or 3 times of doing that to get all the rust and crud outta my cooling system!

Oh yeah do not forget to turn on the heater too!

Kat

Er... CLR. Works miracles.

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"Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blind-folded fear."

-Thomas Jefferson

I think its from running only water for years.It happens alot on boat motors.

it used to happen oin my car then the hgeater core started leaking and I had it changed and it never happened again

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I WOULD RATHER PUSH A CAMARO THAN DRIVE AN IMPORT

1983Z28 350w/ edelbrock performer RPM power package , dynomax shorty headers, 700R-4 with shift kit, 750cfm carb, edelbrock 3" exhaust system, ASCD SS hood, 16" IROC rims.

future mods:
completely done over suspension, black paint with flames, Hurst shifter, dakota digital gauge package, procharger supercharger.

Or get a huge bottle of clear eyes!! It's got to work

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--Steve S--
1984 Trans Am 305 LG4, 5 speed Daily Driver, Flowmaster 80 Series
Holley 600 cfm & vacuum advance
Soon: Edlebrock Intake & TES

Same thing happens to me in my 88. Good to know I am not the only one !

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88 GTA Charcoal Grey Bone Stock except for loose muffler which makes it a bit louder than normal.