Nasty Coolant

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,615
Reaction score
28,848
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
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.

You must be registered for see images attach


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

Full Access Member
Joined
Apr 12, 2017
Posts
16,026
Reaction score
25,571
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
Ive seen the inside look like that but not black. Usually like a brownish green goop.
 

84 M1008

Full Access Member
Joined
May 11, 2018
Posts
363
Reaction score
197
Location
New York
First Name
Wayne
Truck Year
1984
Truck Model
M1008 K30
Engine Size
6.2 diesel
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

B-rate Hillbilly Customs
Joined
Jan 12, 2018
Posts
9,108
Reaction score
15,456
Location
Salisbury NC
First Name
Vince
Truck Year
89, 79
Truck Model
89 Suburban R1500, 79 C10
Engine Size
350, 502
Yuck!
 

82sbshortbed

Fuckemall!!
Joined
Mar 1, 2018
Posts
15,965
Reaction score
53,772
Location
SE Texas
First Name
Doug
Truck Year
1982, 1984
Truck Model
1500 shortbed, 1500 longbed
Engine Size
454, 305
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

Full Access Member
Joined
Oct 22, 2019
Posts
1,878
Reaction score
1,247
Location
Greenwood, SC
First Name
Nate
Truck Year
1980
Truck Model
K10
Engine Size
350
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

Full Access Member
Joined
Jan 23, 2013
Posts
8,884
Reaction score
18,741
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350 w/203
Looks like somebody used Bars-Leaks in it, A LOT!
 

Vbb199

B-rate Hillbilly Customs
Joined
Jan 12, 2018
Posts
9,108
Reaction score
15,456
Location
Salisbury NC
First Name
Vince
Truck Year
89, 79
Truck Model
89 Suburban R1500, 79 C10
Engine Size
350, 502
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

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,615
Reaction score
28,848
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
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

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,615
Reaction score
28,848
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
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

Full Access Member
Joined
Jan 23, 2013
Posts
8,884
Reaction score
18,741
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350 w/203
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

Full Access Member
Joined
May 11, 2018
Posts
363
Reaction score
197
Location
New York
First Name
Wayne
Truck Year
1984
Truck Model
M1008 K30
Engine Size
6.2 diesel
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.
 

Latest posts

Forum statistics

Threads
44,414
Posts
956,957
Members
36,735
Latest member
rljohnson013
Top