Brown-ish Antifreeze

[WestButteTruck]

My coolant in the reservoir looks real brown, almost oily. Could be sludge of some sort I suppose. I really have no idea if it's ever been flushed or not. But was wondering if it could be oil and how to tell. I changed oil last fall before I put it away and have probably put less than 500 miles on it since oil change. But, it was down over a quart and nothing on the floor. Could the intake gasket be bad? Just changed trans fluid, nothing extra there. The fluid in the overflow was well above the "cold" mark after sitting all weekend.

Pickup is an 85 with the 305 and 69,xxx miles.

[WigglesTheHoly]

u have oil getting in somewhere

[Hoods69BadBowTie]

Originally Posted by WigglesTheHoly

u have oil getting in somewhere

Yep that's exactly what I was thinking. I was going to say you had rust & corrosion in there until I read that you were that low on your oil and its not on the ground!

[WigglesTheHoly]

I'm thinking Head Gasket

[jchav62]

Sometimes when people use stuff like Bar's Stop Leak, it turns the coolant brown.

[sierra4x4]

Sounds like cheap antifreeze to me. I've seen that before.

[Hottrucks]

since temps outside are decent I would drop it and flush it with water...alot including the heater core then fill it with water and go for a ride.....I have used CLR with great luck to flush rads and blocks....that is is your water stays clean

[country29]

you can also use powder cascade dish washing powder, NOT LIQUID, to flush the cooling system, then flush with water, blow out the heater core hoses and fill with new antifreeze. just my .02

[USSkoval]

Do not use plain water, in will boil over too soon when in slow traffic.

Oil in coolant is likely from the tranny cooler leaking internally in the radiator. There's really no way for the head gasket to do that, unless it's coolant in the oil, rather than oil in coolant.

[Hottrucks]

water boils @ 212 plus a 10LB cap will add 20* so your at 232ish....if your system is in good shape it will be ok if the outside temp isn't really hot to start with...I ran my 70 half the summer with just water ( I was doing alot of front end work pulling the rad and water pmp stuff)....anyway its only for a test drive it will get your oil and trans pressure up

other than that I agree ..I would find it hard to be motor oil in the rad

[tucsonjwt]

I used stop leak powder after I put in a new radiator, water outlet and hoses. Still had a small leak around the intake in front. Stop leak did the trick, but I do have brownish fluid instead of green (Peak) antifreeze in the overflow tank. The radiator itself has nice green fluid. I don't burn oil, just about 1/2 quart lost through rear main seal leak every 1000 miles - supposedly not bad for a 454. I think the brown stop leak residue might be suspended throughout the system, but it precipitates out in the overflow tank because that coolant does not circulate much.

[WestButteTruck]

Well, I think I'll flush it first and see what I get back. My Grandfather bought this new in 85 and I really doubt the coolant has ever been changed.

[andrewmp6]

Yeah just flush it if it comes back quick then you got problems.