Really goopy radiator

[CoolMick]

Picked up this 94 4.0 a couple days ago and just now had the time to take a good look under the hood, on a scale of 1 to 10 how concerned do y’all think I should be about a cracked head/blown head gasket just based on this chronically dirty radiator… oil looks good and no white smoke out the exhaust. Runs pretty strong. Has anyone seen corrosion in the rad that looks like this?

I’ve got a 2.3 L as well that I replaced a cracked head on a year ago that didn’t start showing signs of it until I started replacing parts for the cooling system that had gone bad, hoping that I haven’t set myself up for round two.

 

[Curious Hound]

I'd do the Prestone radiator flush a couple times and then watch it for a while. Get the whole cooling system clean.

 

[CoolMick]

I'd do the Prestone radiator flush a couple times and then watch it for a while. Get the whole cooling system clean.

A flush is definitely first on my list, I was going to just use distilled water but I will get the Prestone flush instead.

 

[CrabGuy]

That could be the result of an older HG failure, cracked head, or some over application of Stop Leak compound. It looks like old oil in the coolant system and they didn't do a flush. I've never seen black gel from mixing Dexcool with green coolant. That will take a multiple aggressive flushes to get it out of all components in the system. Hopefully you'll luck out and dodge a bullet. I had a 3.8 Chevy V6 that kept overheating on hills so it fouled the cooling system with oil instantly due to faulty intake manifold gaskets. The oil never showed a drop of milkshake due to the difference in pressure between the cooling (16psi) and lubricating system (45psi).

 

[CoolMick]

That could be the result of an older HG failure, cracked head, or some over application of Stop Leak compound. It looks like old oil in the coolant system and they didn't do a flush. I've never seen black gel from mixing Dexcool with green coolant. That will take a multiple aggressive flushes to get it out of all components in the system. Hopefully you'll luck out and dodge a bullet. I had a 3.8 Chevy V6 that kept overheating on hills so it fouled the cooling system with oil instantly due to faulty intake manifold gaskets. The oil never showed a drop of milkshake due to the difference in pressure between the cooling (16psi) and lubricating system (45psi).

So far my track record for dodging bullets isn’t so good, I’m feeling like a sucker currently lol. I’ll start with some thorough flushes and go from there.
My 2.3 L ranger also never had any milkshake when it had a cracked head, so I’m for sure not ruling it out as a possibility with this one

 

[rusty ol ranger]

Is the truck an automatic?

If the trans cooler thats built into the main radiator is leaking it can cause that.

However that does look more like oil gunk.

 

[superj]

flush multiple times and keep an eye on it, for sure. and you can check compression and do a vacuum check too, just to get a little more info

 

[CoolMick]

Is the truck an automatic?

If the trans cooler thats built into the main radiator is leaking it can cause that.

However that does look more like oil gunk.

It is a manual

flush multiple times and keep an eye on it, for sure. and you can check compression and do a vacuum check too, just to get a little more info

Good idea, I’ll add those things to my list.