Frank1959

Hello all and thanks for any suggestions in advance. I must say ahead of time, I'm not a mechanic and I don't pretend to be one, just trying to keep my old gal running. My 92 f150, v6 , automatic, just started overheating. No antifreeze leaking anywhere. Water pump was replaced a little over a year ago. I thought maybe thermostat was stuck closed but I removed it and tested it and it was fine and I even put it back together with NO thermostat just to be sure, still begins to overheating within about 15 mins. The water pump doesn't make any noise, there is no play or wiggle. There is no signs of head gasket issue. Oil is clean, no smoke, no loss of power. If I start the truck with radiator cap off, the antifreeze definitely does not appear to be circulating. Sort of just sits there. I guess my question is can the water pump be bad and not circulating coolant even though it isn't leaking and impeller shaft doesn't appear to be wobbling or anything? I did notice that belt tensioner started squeaking and I thought maybe the belt could be slipping and not turning water pump shaft properly? But there's no other signs of a loose belt issue.....anyone have any suggestions? I greatly appreciate any help in advance and thank you.

Steve83

For us to help, we have to know what you're working on. There was no V6 in these trucks, so you need to click this, read the caption, study the truck, and put all its details into your signature so we can review them with each reply:


(phone app link)

When an engine overheats, it's ruined. If yours still runs, it didn't overheat. What exactly did you observe that makes you think it got hot?

Why exactly was the WP replaced? With what (brand, PN, source)? By whom? What coolant mixture was the system refilled with?

At low RPM, the flow through the radiator may not be enough to see at the filler neck. And yes: a WP can fail in a way that's not observable. Read the article linked in this caption:


(phone app link)

greasyknuckles

If there is no circulation with the thermostat removed, I would remove the water pump, hold the impeller and turn the other end.
I have seen many rebuilt water pumps that the impeller is spinning on the shaft

Frank1959

Sorry, I should have been more specific. It is a 92 f150, 105 k miles, automatic, 4.8 liter. The water pump was replaced at a local garage, it was a rebuilt, purchased at Auto Zone. I use a 50/50 store bought coolant. The temperature gauge on my way home from work was pinned on the hot side, I immediately pulled over and shut the truck off, I waited an hour till it cooled down and was able to drive home the last 2 miles. Since I've removed the thermostat I drove it up and down the road and it begins getting hot after about 15 mins. Again, there are no external leaks, the upper hose gets screaming hot and hard as a rock. I hope this helps, as I said I am not a mechanic, just trying to keep the truck running without spending a ton of money as I really enjoy the truck. Thanks again

Steve83

There was no 4.8L, either. And it all needs to be in your SIGNATURE.

Frank1959

4.9 typo