Water pump failure? (main engine)

Keep in mind that our driveway is after a absolutely brutal 10 mile climb.
It started with a little 6" spot of coolant, directly under where the pump is.
Then after a couple months a large puddle randomly.
Long story short I honestly believed there was a pinhole in the radiator, so I added some K-Seal which I've had great luck with before on other vehicles.
The leak persisted, and I realized that the K-Seal had never mixed with the coolant. It was still sitting on top of the reservoir. And I realized that the coolant spray was from the overflow tube hitting the running fans.

So I ordered a pump and it arrived today.

Now, I have no heat. Even after the brutal climb. The radiator resevoir is still full all the way up to the neck, and the radiator itself was cold when I got home.

So, is it probable that the pump's propeller has come off? It seems like there is no circulation.

 

That is what is so strange. It acts like it has a bubble in the system, but at the same time I have never added coolant, and the resevoir is always full, yet it has overheated enough to blow coolant out the overflow. I suspect that the boiling of the coolant has created a gas bubble that is trapped.

Now, why would it have overheated? The fans work. And the damn car won't tell you how hot it's running (blows my mind)

 

Well you were correct. The radiator was definitely low, or empty. I put some crap coolant in as a test only because I will be flushing it soon.

Coolant is now flowing to the heater core.

But, it's spewing coolant out of the reservoir during normal, not stressful conditions. The coolant spewing is not super hot. I observed this even when parked. Then I cycled the power to allow for the minute or so idle sequence.

What I noticed was something very odd. When the engine is idling, what is the load that is placed on the engine? ICE? Is that all? It was spewing coolant out the reservoir cap until the load was released just before the engine shut off. When the load was released, the spewing stopped.

Scratch your head on that one.

 

Great to hear that the simple little cap may be to blame. I have blown enough head gaskets to get pretty derned concerned when coolant systems become over pressurized. I still haven't ruled that one out. Its little ticker has moved that car 299,540 miles.

It has never seen a major front end collision.

So, I'm preparing parts to do a lot of other needed work up front, and I'm going to throw a new cap in the mix. I'll remove the catch bottle and inspect it. Flush the crap out of the system (litterally), and ensure that purging takes place properly.

Although, the little neck coming of the radiator has the overflow port below the radiator cap, IIRC. That would mean unregulated pressure is allowed into the catch bottle, where pressure management should be regulated. Shoot I don't know. Even that cap has a port that allows overflow coolant down a tube to who knows what. Probably just a dump. I'll dig into it and report back.

Thank you so much for the advise. It is much appreciated. Everything on this car seems little and kinda toy like as I work on big diesels normally so this is a fun little project.

 

Oh one more thing. If the radiator was empty and therefore the system extremely low. I am concerned about overheating during my climb home, but I've felt the block, coils, and head with my bare hands when I get home and it doesn't feel too hot, and no ticking while it's cooling. I think I can thank the cold weather we had last week. It was below zero, and I bet that kept things cool.

Here is the drive that taxes the system. It's only about 2000' change, but most of that is within 5 miles and it really pushes that motor to the max. I drive below the speed limit because too much throttle causes a vibration at high RPMs. But I've tried going from my careful throttle position to WOT and noticed that there is barely a discernible change in acceleration.

 

I'm starting to believe the radiator cap did have something to do with it. I noticed that when removed after complete cool down, it was either holding a vacuum or pressure in the system. When it was holding pressure, the coolant would bubble out of the neck for a few seconds.

I put a new cap on, and didn't see any new coolant spew when I got home. Tomorrow I'm going to clean the thing up and test again, I'll let you know.

 

And I have no problem changing a head gasket. Just from the looks of things in there, I could probably get it done in a couple hours, if the deck does not need surfacing. Not that I want to do it on a motor this old and worn.