Gusog

Hello all, new to us truck, we have had it about 4 months, I like it, wife not sure yet.
98 F150 5.4L 4X4 Supercab
​​​​​​We have a couple issues, previous owner had no coolant in system and I did not check it. Some cold nights here in southern Nevada and the radiator split. Also pushed out a freeze plug. Replaced everything, now I have a running water sound from under the dash, right side, and the water temp is up and down on the gauge. Suggestions?

LWJ

Sounds like it needs to be burped. You might have air in system.

white89gt

Not sure if you like your Wife yet, eh? J/K

If you're not seeing wetness on the passenger floor or out on the ground, I would agree with LWJ. Probably air in the system.

BareBonesXL

It should diminish and disappear over time, if I understand the system operation correctly. Air, vapor, and excess fluid from heat expansion gets pushed in to the reservoir, liquid only gets pulled back in as it cools off.

Lots of stuff around about burping but it's not super clear that it's necessary. How far "up" on the gauge is probably the decider.

white89gt

If he can hear it, the system has some big pockets in it. Risky business not getting it fixed.

BareBonesXL

That's why I mentioned the gauge.

I hear what sounds like water flowing down by the passenger dash area whenever I shut off my 4.2 V6. But the gauge is steady. I often wonder why there's no burping procedure in the service manuals.

LWJ

With no coolant in system for how ever long it was, the heater core might now have a blockage in it ( passenger side, under dash). This could also make it harder to remove the air in your system.

white89gt

You also said "It should diminish and disappear over time", which is not going to work for what he is experiencing. Considering the history of the motor, he can't wait it out.

As far as a procedure is concerned, the best method I have found on the V8's is to fill the radiator from the top hose port, not through the overflow. Leave the cap off the overflow tank while doing it. I am 100% in getting it right the first time using this method.

BareBonesXL

The coolant froze in the engine. It didn't overheat. History is irrelevant. All engines start with no coolant in the passages. Just air. Nobody can say what will work, or what is necessary.

Just being logical.

p.s. the proper name is "core" plug, not freeze plug. They aren't there to protect the engine from freezing, they're just part of the casting process. Just coincidence that they pop when the coolant freezes. The OP could very well have a cracked block.

white89gt

LOL... your "being logical" is comical. "not a big deal, it'll all work out, it's just air, it didn't overheat................... but, he could very well have a cracked block". Which is exactly why it needs attention ASAP.

Like you said, nobody can say what will work, but just ignoring it and waiting it out is not correct. That was your original suggestion. Let's try and help him solve this rather than tell him to wait it out.