Any ideas what this could be?

[pmpski_1]

The engine starts getting really hot - seems like it's not getting the coolant it needs.

There is a strange substance in the radiator and the coolant is an off color. Bought a new thermostat and tested it before installing, so I know it's working.A buddy says it's got to be the head gasket so I started tearing it down. I haven't got the heads off yet, but I came across this stuff after taking the manifold off.

Any ideas about what this could be? It's soft like butter and feels slightly oily, but it's solid. There's a slight bit of it on the inside of the hoses too, but it's just a light coating, not built up like this. I've never seen oil from a blown head gasket, so if it's that obvious, well, I can chalk it up to lack of experience.

[Boog]

I think it might be some sort of cooling system leak repair product. And if your engine coolant passages look like that then the radiator has got to be all clogged up too. More work ahead.

[sandking]

What does your oil look like? That looks like water and oil mixed. Could be a head gasket or possible worse, a crack somewhere.

[pmpski_1]

The radiator is going to get cleaned and tested tomorrow. I didn't put anything in there, and I believe it was a replacement when I got the truck. It was ok before the rebuild.

The engine is fresh. The oil on the dipstick looks good, but I haven't drained it. It looked good when I drained it after cam break in, although we did stop short because it got too hot.

The only thing that I can think of is if it busted the head gasket after we shut it down because of the heat, then mixed the oil and coolant the next time we ran it.

Heads are coming off today, radiator is getting tested, but the mystery behind the goo is still a mystery at this point.

[dave2953]

I could be wrong, but that looks like the Dexcool buildup that I used to see at the Cadillac dealership. Do you use Dexcool coolant?

[mclairmo]

Whatever it is, you have to get it out of the engine or it will not cool. The coolant/water needs to touch the inside walls of the coolant jackets to transfer heat. What a mess.

[pmpski_1]

Got the heads off. I'm getting the radiator cleaned and tested tomorrow. This engine has been run for less than an hour since the engine went back in. It came out last year for another problem, and there was no gunk in it. This is the first time it's been run since it was disassembled, inspected, and re-installed since last time, so this is something that is a recent happening.

The radiator sat for a year, but other than that everything is the same (except the screw in rocker studs, pushrods, and pushrod guides, but that's another story that I should update my build thread with).

Hopefully the radiator guy can tell me something so I can pinpoint it. If not, we'll clean everything, inspect it, double check it, and put it back together.

Anyway, more pics.

1. Close up of the gunk.
2. Coolant. There is some ATF in there - a bit dripped in while pouring in from the radiator. No, that's not ALL of it, but it's a good chunk of it.
3 and 4. head gasket.

[mr48chev]

I'm with Boog, that looks like the residue from some sort of stop leak concoction. Or the results of mixing coolants that are not compatible.

If my info is right the Dex-Cool doesn't mix with anything and creates issues.
From doing a google search it looks like the Dex Cool has enough problems on it's own to not need help from mixing with other coolants.

You said "since it was disassembled, Inspected and resembled", What did the engine come out originally" and what did the radiator come out of?

At the very least when I put it back together and back in I would run a good engine flush through it before putting anything except water back in it. I would be tempted to take it to a shop that had a power flush setup this time around.

[RustyBucket]

Has your radiator got the transmission cooler inside? I wonder if it leaked inside the radiator what kind of mess would ATF make in the cooling system. Have you looked at trans. dipstick. The stuff in your pictures looks kinda reddish colored. Just another guess what it might be. Sorry 'bout your trouble.

[pmpski_1]

48Chevy

Long Story Short:
1. Built entirely fresh 350, existing radiator.
2. Drove less than 100 miles, break in period, had a major failure in the valvetrain.
3. Removed engine, broke it down to long block, inspected everything. Engine sat for a year.
4. Recently replaced necessary valvetrain components, installed engine, broke in cam. Got too hot during cam break in and shut it down.
5. Noticed said gunk in the radiator, more as I disassembled.

I put in Prestone this time around. I'm pretty sure that's what was in there before due to the number of empty Prestone bottles in my garage I'm not familiar with Dex Cool. What is it?

RustyBucket - yes, the trans cooler is in the radiator. That's one of my theories as well, hopfully Radiator Guy can tell me if there's a problem there.

Either way, the consensus is, clean and test radiator, check for cracked heads, flush coolant system, put it back together and hope it doesn't happen again. I just hate not knowing exactly what this stuff is, and I don't think I'm going to send it off to a lab to get it identified. I look at it this way - if you don't know exactly what it is, you don't know if you really fixed the problem. However, as long as I do the right things, it should turn out ok.

Thanks for the answers, and I'll update this thread once I get the scoop from Radiator Guy.

[RustyBucket]

.........kinda looks like the toilet bowl the day after a bad drunk
well, you asked for any ideas what this COULD be

sorry, sometimes I just can't help myself

[pmpski_1]

I've been changing a lot of diapers over the last 15 months...I thought about that too

[70gmcjimmy]

It sure looks like a mix of normal "green" anti-freeze and that damm pink anti-freeze. It will make the coolant look like what you showed and will form a muddy looking sludge that will collect thoughout the cooling system.

Later---DAC

[Arizona oldguy]

Worked on a truck one time that had trans fluid in the coolant, the one thing I remeber most about the trans fluid was that it started to make all of the hoses mushy and swelled up like a poison toad, I am not really sure what a swelled up poison toad looks like but I heard that saying many moons ago and it stuck. Could be the trans cooler though. Good luck

[mclairmo]

Sounds and looks like the trans cooler in the radiator is leaking. Is the trans fluid looking funny? Is it low of trans fluid now? I would check the trans fluid and change it if coolant mixed with it.

[Boog]

Roger that. Just a little bit of water in the tranny fluid will steam the clutch disc material right off them leading to a rebuild.

You will no doubt have to run a cooling system flush through it a couple of times to get as much of this sludge out of it as possible or it will make it's way to the radiator and plug it up again. If the stuff cannot be disolved it must be flushed out.

[pmpski_1]

Got the radiator cleaned and tested today. Nothing out of the ordinary, everything is ok.

He did show me where it had been repaired in the past - after cleaning it up you could see the seam that was repaired. He said it was probably a leak stop product that got unclogged during the cam break in.

Anyway, radiator is good, now on to flush the rest of the sytem. I can flush it here in the driveway with a hose. Is there any advantage to getting it flushed at a shop too? Is it much higher pressure? Seems like 50 bucks for a pro flush is good insurance...

[mclairmo]

Has the root cause of the sludge been determined? I think that needs to be done before this all goes back together or the same thing may happen again.

[pmpski_1]

Originally Posted by mclairmo

Has the root cause of the sludge been determined? I think that needs to be done before this all goes back together or the same thing may happen again.

No, and that is what makes me a bit nervous. If you don't know the root cause, how can you verify you fixed it? However, I can verify that all of the pieces are good individually.

My buddy will inspect the head gaskets this week - I can't say I've ever witnessed a blown head gasket, so I can't comment on this one. Maybe it's subtle and I don't know what to look for.

So, we know the radiator is ok, there will be new head gaskets, we'll flush everything out of the cooling system, drain the oil (which looked fine after cam break in and on the dipstick now), and see where we are.

Short of getting a lab analysis of the gunk I'm not sure what else to do at this point. I should have taken some in to the radiator shop today. Maybe I'll stop by there tomorrow.

I guess I could drop the pan to see what's in there, but I'll drain the oil and check it out before I decide whether that's necessary.

One thing I forgot about - I did install a brand new heater core before we fired the engine this time around. This was the only thing that has changed since it was last running. Anyone ever hear of a new heater core being full of crud? It was brand new, in the box, purchased from a board vendor. I did test it before installing it and no crud came out of it.

[BluTrukker]

A friend of mine had a head gasket go bad at about 120,000 and his coolant looked exactly like what what was in the bucket that rustybucket posted. sorry I couldn't see any of your pics, they are blocked at work. His coolant had never been changed though.