94' F350, 7.5L with E4OD. Went to do a coolant flush yesterday, and the coolant was a orangish rust color and thick like a milkshake. Same gunky stuff in the overflow tank at the bottom.

So I completely flush the system, took off the overflow tank and cleaned it out and put it back. However, the system would only take 3 gallons of coolant, and it is supposed to have a 5 gallon capacity.

I removed the top and bottom radiator hoses and had the truck parked downhill in my driveway so that the remaining water in the engine passages would pour out.

Any ideas on why the cool it would be thick and this color? I'm hoping no oil in the coolant, I can't afford the downtime of taking the heads off. Also, any ideas why the system wouldn't take the full capacity of coolant?

 

I can only think of oil being in the coolant. On one motor I had there was a problem with how the head gaskets were installed. That made the oil mix with the green coolant. With the pressures in the motor, the oil and water mixture emulsified and it came out as you described. Do you have coolant in the oil? Are you losing oil?

 

No coolant in the oil or oil loss. However I'm thinking it may be the built in tranny cooler. Got corroded and is bleeding over?

 

I don't see how that could happen without you noticing something else. Each one of those are sealed systems

 

Yes they're sealed but if the transmission cooler sectionsl corrodes, it can do so through to the coolant passages.

 

Ok here is a picture of where the transmission cooler lines come into the radiator:

<a href='http://postimg.org/image/bnmdccskf/full/' target='_blank'><img src='http://s19.postimg.org/fwr3eivtv/20140416_201921.jpg' border='0' alt="20140416 201921" /></a><br /><a target='_blank' href='http://postimage.org/'>free upload image</a><br /><br />

There here is down the spout:

<a href='http://postimg.org/image/k8kah9s4f/full/' target='_blank'><img src='http://s19.postimg.org/lnlv5zt7n/20140416_201931.jpg' border='0' alt="20140416 201931" /></a><br /><a target='_blank' href='http://postimage.org/'>free upload image</a><br /><br />

And here is where the lines go to an external transmission fluid cooler due to the super cooling package:

<a href='http://postimg.org/image/spf7eg7fj/full/' target='_blank'><img src='http://s19.postimg.org/utzkfj92b/20140416_202025.jpg' border='0' alt="20140416 202025" /></a><br /><a target='_blank' href='http://postimage.org/app.php'>capture</a><br /><br />

Where the lines go into the radiator I can look straight down and put a stick straight down to the bottom of the rad, so I'm not sure where the radiator sections are sealed.

 

I think you just have corrosion and sediment build up due to lack of maintenance. There will still be some coolant in the block and heater core, even if the hoses are disconnected. When we have a lot of corrosion or a partially clogged heater core at the shop we will dump in a bottle of CLR and let it soak. Rinse it out with water and the flush machine, and put in new coolant. Some people have had luck removing the thermostat and flushing the block with the a hose. Alternate between the top and bottom hoses until you get a mostly clear stream.

Trans fluid & coolant will give you "strawberry milkshake". Very obvious when it happens.


Your system doesn't look too bad. Go to Google Images and search for "Dexcool buildup". It could be far, far worse. I've seen it first hand.

 

yeah yours looks just fine

 

That's after I flushed and refilled.