Orange/Brownish Coolant

[SleepingTsi94]

My new motor has about 3000 miles on it and I was fixing a coolant leak today and the coolant was not green like I when I put it in. What makes the color change? I Flushed it and refilled just to be on the safe side.

 

[PieEyedPiper]

I'd be thinking rust immediately if the color was orange or brown. When was your water pump last replaced? What is the condition of your radiator?

 

[95blackGsTurbo]

Did you replace your radiator when you replaced the motor. GM has a HUGE problem with the stock rad. in there 4.3L Blazers and stuff with the radiators getting rusted internally. I would flush it with some gasoline and see if you can get it a little cleaner. Then flush it really good with water. Is the motor rebuilt new, or used new?

 

[GST with PSI]

Did you replace your radiator when you replaced the motor. GM has a HUGE problem with the stock rad. in there 4.3L Blazers and stuff with the radiators getting rusted internally. I would flush it with some gasoline and see if you can get it a little cleaner. Then flush it really good with water. Is the motor rebuilt new, or used new?

Gasoline... I think not. Gasoline is petroleum based. Anti freeze, depending on what type you use, is mainly ethylene glycol based. Not a good combination. Whatever you flush your coolant with needs to be 100% compatible with the coolant you are running. Gasoline does not fall in that category. You will never get all of the flush out of your cooling system unless you tear each piece of the engine apart and clean it individually, a task few will attempt or complete. Tee into your heater core inlet with a garden hose and run the car with the radiator petcock open and cap off. Begin this process when the vehicle is cold, to avoid rapid contraction and damage of any hot components. With the hose on full blast, start the car and let it idle for 15-20 minutes, or whenever the water coming out of each end is running clear. That should get rid of much of the contamination.

If the coolant you originally drained out of the car when you rebuilt your motor was brown, I'd guess the reason your coolant started turning brown in the first place could be blamed on old stop leak. I'm sure since you're probably not the original owner, someone in the past may have dumped the cooling system full of stop leak. That stuff will stay in the system for life when introduced. It builds up in cracks and crevices over time and settles in the cooling system when the old coolant's detergents have worn away. When you rebuilt the motor you probably changed the old coolant with new, and stirred the stop leak that had deposited in the system. Now your new coolant, full of new detergents, is flowing through your old stop-leak contaminated system breaking loose all of the old deposits. In the end your pretty new green coolant looks like raw sewage. Cool...

 

[95blackGsTurbo]

We used gasoline all the time at the dealership I worked at to clean out gummed up radiators. Just like using it in an intercooler. Just have to flush the radiator real good when you are done and let it dry. It will all come out. It is just like brake clean except it's already in a liquid form. Don't flush the block with it because you will never get it out but doing the radiator is fine. Or they do make coolant flush liquids, which are just as corrosive as gasoline to break up the crud and flush it out. Either way.

 

[GST with PSI]

We used gasoline all the time at the dealership I worked at to clean out gummed up radiators. Just like using it in an intercooler. Just have to flush the radiator real good when you are done and let it dry. It will all come out. It is just like brake clean except it's already in a liquid form. Don't flush the block with it because you will never get it out but doing the radiator is fine. Or they do make coolant flush liquids, which are just as corrosive as gasoline to break up the crud and flush it out. Either way.

User preference i guess..

Your right, the coolant flush products are probably as corrosive if not more than gasoline. However, the difference is aftermarket flushing additives are produced to be compatable with antifreeze because the manufacturer knows it's impossible to extract all of the left over flushing agent. Flushing additives are made with this in mind, meaning if used correctly according to the munufacturer, they won't destroy anything if a small trace is still in the cooling system after a flush. I guess petroleum in your system (and there will be some left, no matter how good you fulsh it) won't really destroy anything in small quantities, buy why take the chance?

I trust gasoline in my fuel tank, other than that I wouldn't use it for anything else. But hey, whatever sparks you fire, literally. .

 

[nightspeed87]

i used it for my intercooler

 

[sheldon]

If its brownish then its most likely oil...If the head wasn't decked properly then your head gasket might not seat properly causing the oil to mix with the coolant and putting a new headgasket on will not fix it...it will need to be redecked...when you say new motor are you meaning a rebuild?

 

[SleepingTsi94]

yes everything done by a shop...the last motor had waterpump go out i found out so i think the owner might have put the stop leak crap in and it got in to the heater core and since its getting cold now it coming out...

 

[robs90tsi]

If its brownish then its most likely oil...If the head wasn't decked properly then your head gasket might not seat properly causing the oil to mix with the coolant and putting a new headgasket on will not fix it...it will need to be redecked...when you say new motor are you meaning a rebuild?

Its not oil, oil would make it soupy brown, its just rust, this happened to me, just flush it a couple of times and youll be fine, ive drained and filled my coolant around 6-8 times within 8 months, and the brown was gone completely the first time, only because i flushed it for a long time, i just ran a garden hose through it and let it drain right out the radiator until nothing but clear water came out.

 

[sheldon]

Its not oil, oil would make it soupy brown, its just rust, this happened to me, just flush it a couple of times and youll be fine, ive drained and filled my coolant around 6-8 times within 8 months, and the brown was gone completely the first time, only because i flushed it for a long time, i just ran a garden hose through it and let it drain right out the radiator until nothing but clear water came out.

Have you seen it in person? have you felt it with your two fingers? Man dont sit there and say you know for a fact that its not oil...if its a brownish color that looks like choclate milk than it very well could be oil

 

[sheldon]

yes everything done by a shop...the last motor had waterpump go out i found out so i think the owner might have put the stop leak crap in and it got in to the heater core and since its getting cold now it coming out...

I dont know the shop that did it...but shops do mess up from time to time...it would suck if it is the case....rule out the rust and keep a close eye on your oil level...and only time will tell

 

[95talon_in_ma]

Not sure about the 1g's but wouldn't they have an aluminum radiator also? It's definitely not the radiator rusting if it's aluminum...
More than likely it is just rust. Both my Talons did this and my girlfriends Galant does it too.
Oil in the water is not so bad as water in the oil. Pull your oil cap and if there is allot of white foam in there, then you might want to pursue further....
Otherwise just flush it a few times.

 

[vr4play]

Have you seen it in person? have you felt it with your two fingers? Man dont sit there and say you know for a fact that its not oil...if its a brownish color that looks like choclate milk than it very well could be oil

the title says "orange/brownish". I've never seen orange chocolate milk.

Even after you flush it, you will probably need to revisit it a few more times. Rust tends to keep showing up for a while.