Nasty Coolant

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bucket

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Little bit of backstory for starters...
'88 Suburban with original TBI 350. Purchased in early '06 I think,with a little over 100k on it. My wife ran it low on oil a few times, to the point of valvetrain noise. Somewhere around '09-'10, while cranking along the interstate all day, I overheated the oil, to the point the rods were hammering like crazy (it was fine when it cooled down). I think it was early '13, after a trip into Indiana, I noticed that oil consumption had increased by a large amount. My wife then ran it out of oil a few more times. Then it started using coolant. I think it was spring of '14 maybe that overheating issues began, from the thermostat not opening due to airlock. The housing bolts felt like they were going to break, so I pulled the hose off and stabbed a big screwdriver through the thermostat. The wife and kids didn't need heat in the summertime, lol. At around 200k on it, it also began missing badly and horribly fouling out a couple spark plugs. Sometime around there, I started buying other Suburbans for the wife to drive. The trusty ol Burb didn't get driven much after that, just some trips here and there, some general farm type use, and the occasional mild offroading. Then sometime in '17, I pulled the transmission out of it to sell to a friend. Last week I finally installed a new transmission.

Ok, so I guess that wasn't just a little bit of backstory. Sorry for the novel. But anyway, the truck's coolant had been kinda brown-ish looking for a while. When I got the truck back up and running, the coolant level was low enough that I couldn't see it. I dumped in a gallon or so of water and called it good. Today, I was curious if it had lost coolant, so I took a gander and I honestly was startled with what I saw, lol.

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Now, I've opened a lot of radiators in my days of working in shops and at a junkyard. But I don't recall ever seeing anything in a radiator that looked quite like that mess.

The truck runs terrible, it's down a cylinder or two, the exhaust sounds ridiculous, it smokes when you rev it up, and it's got a remarkable amount of blow by. I'm 100% OK with that too. But now I kind of want to tear into it to figure out what the heck is going on in there.
 

78C10BigTen

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Ive seen the inside look like that but not black. Usually like a brownish green goop.
 

84 M1008

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That looks like ancient radiator sealer. Don't shoot the messenger, but that engine has been overheated and run low on oil so many times it's more than likely done.
 

Vbb199

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Yuck!
 

82sbshortbed

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Wow, I'd say busted head gasket is why you're getting the white smoke and coolant consumption. Probably broke from over heating it a few times and that's fowling your plugs.

I've never seen black goop like that tho. I would guess oil has gotten in there then overheated a few times cooked the oil into a sludge. :shrug:

That's nasty looking tho
 

80BrownK10

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Why not just get a good used engine. Won't be hard to get one cheap that's 10x better than that one! Haha
 

Snoots

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Looks like somebody used Bars-Leaks in it, A LOT!
 

Vbb199

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Pull the radiator out, connect both hoses together and forget about it lol
Cast it down into the bottom of the sea in a concrete coffin like radioactive waste lop
 

bucket

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That looks like ancient radiator sealer. Don't shoot the messenger, but that engine has been overheated and run low on oil so many times it's more than likely done.

Why not just get a good used engine. Won't be hard to get one cheap that's 10x better than that one! Haha

Looks like somebody used Bars-Leaks in it, A LOT!

The truck has actually never had leak sealer put in it since I've had it. The cooling system was perfect when purchased. It hasn't been overheated technically more than once, just ran hot several times. And I've got other engines I can put in, but this one runs better than the truck looks, lol.
 

bucket

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Wow, I'd say busted head gasket is why you're getting the white smoke and coolant consumption. Probably broke from over heating it a few times and that's fowling your plugs.

I've never seen black goop like that tho. I would guess oil has gotten in there then overheated a few times cooked the oil into a sludge. :shrug:

That's nasty looking tho

I do think there's a wasted head gasket, but I believe that was failing and caused the higher temps, rather than the other way around.
 

Snoots

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In that case I'd flush the entire system, pull the radiator and have it boiled and rodded then re-fill it and try again.
 

84 M1008

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The truck has actually never had leak sealer put in it since I've had it. The cooling system was perfect when purchased. It hasn't been overheated technically more than once, just ran hot several times. And I've got other engines I can put in, but this one runs better than the truck looks, lol.
 

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