A customer (and a buddy) recently brought his nostalgia-flavor Ford Thunderbolt clone (equipped with a vintage 427 FE) to my shop, complaining of high engine temperature issues, primarily at idle.
The water temp at idle would routinely reach in the area of 210 to 220 degrees F., often continuing to gradually climb even higher.
While not at a terminally fatal level, the concern was still there, especially because the engine still took a while to catch up and recover back to the 190 range.
Naturally, we looked at all of the obvious areas, including air in the system, thermostat operation, radiator condition, fan, airflow, shroud, engine timing, etc.
To make a long story short, he had purchased an aftermarket water pump (I’ll omit the brand here) because he had read favorable comments about the pump on an internet forum that touted this pump as a killer pump at a cheap price.
Once we suspected inadequate water flow, we pulled the pump and found that the impeller was designed for universal rotation (to accommodate V-belt or serpentine belt).
In fact, this pump didn’t do a very good job in either direction. We pitched it into our trash bin and installed an Edelbrock aluminum pump, and that fix immediately solved the problem. She now idles at a stable 185-190 degrees without a hiccup.
Just because a few folks recommended the inexpensive pump, the customer didn’t see the need to spend a few more bucks for a trusted brand name. Usually, you get what you pay for, and this was a perfect example.