E-Series Coolant System Question

[BrianBlair]

I’m troubleshooting a coolant issue and am hoping you all can help.

I’ve noticed that coolant doesn’t seem to move from the radiator to the overflow tank and vice versa. I pulled the hose that goes from the radiator neck to the overflow and sucked/blew into it and it seems like the hose is blocked/pinched/clogged. I cannot blow into the tank through the hose at all.

Before I tear into this and start moving stuff out of the way…….this hose between the radiator and overflow should be free flowing…..right?

[hogasm]

Yes free flowing

[JWA]

What coolant issue are you trying to diagnose and/or repair?

Checking whether coolant will flow from the degas bottle into the radiator you can watch the level in the bottle as the circulating coolant in the engine warms and draws from the degas bottle.

[Twoxentrix]

A while back I read a discussion here that strongly suggested replacing the radiator cap, if I recall it had something to do with the cap spring not functioning properly which could/would cause coolant system issues since it didn’t maintain the proper pressure.
They are inexpensive, but since you’re into the coolant system you might do that at the same time if you haven’t already.

[BrianBlair]

Finally figured out the problem today……

For a while now I’ve been noticing that the coolant level in the expansion tank never changed. I started worrying about everything working properly so it pulled it all apart. Turns out the drain neck on the expansion tank was completely clogged and wouldn’t let coolant flow out of the tank. Cleaned that all up, replaced the hose and radiator cap and all seems to be back to normal.

Thanks all!

BB

[JWA]

^^^ That's an interesting find to be sure----what make, year and engine in your van?

The next question becomes how or why did that opening become clogged or plugged that the 16 PSI of pressure didn't dislodge it.

[carringb]

I was wondering that too....

Usually coolant lines don't plug up, unless incompatible coolants were mixed...

[JWA]

Originally Posted by carringb

I was wondering that too....

Usually coolant lines don't plug up, unless incompatible coolants were mixed...

My first thought and greatest fear is some of that Barr's Stop Leak crap had be introduced somewhere along the line.

[BrianBlair]

This van is a 1993 e250 with the 351.

I wasn’t aware that some coolants don’t play well together…..what’s the rule of thumb on that?

[Kibo]

Long story short, don't mix orange and green coolants. When mixed, they will form a gel-like substance that clogs passages.

The real issue is due to mixing the inhibitors (IAT vs OAT/HOAT), but people are most familiar with the coolant color.