quick question

How many of you have had to replace your northstar engine at a reasonable mileage? Mine had to be be replaced 4,000 miles ago with only 147,000 miles on the engine. Please comment.:confused:

What happened to your Northstar that you had to replace it? There's some out there with over 400,000 miles, so it's very strange that yours is a goner!

My car overheated due to a fan blade cutting into the radiator that got stuck. Coolant leaked out and fans were unresponsive due to one being stuck. I towed it to a mechanic to diagnose, he said that all that needed to be replaced was the radiator. I asked him several times if the engine was ok and he said yes every time, however I believe that he never did any pressure tests to it. Within the next few months I had coolant leaks in different spots most were fixed by mechanic and a couple times by me. Turns out he was just fixing coolant leaks never doing a pressure test. Four months after it overheated I knew it was a goner, coolant out the tailpipes. I took it to a different shop to replace the engine, they talked to many people and found out that the bolts in the block are not heat treated enough thus pull out causing the head gasket to go, my guess is to the one time it overheated... WOW over $5000 dollars later 97 caddy seville sts

It's very common for ANY engine that is overheated to blow out a head gasket. The head bolts pulling from the block is common on the older Northstars. The engine doesn't need to be replaced, the block can be repaired with Timeserts and last for many more years. It typically costs around $3,000 to have that done, most of which is the labor of removing and re-installing the engine.

The Northstar engine has a low-power operation mode for low or no coolant situations.
It alternatly shuts off fuel and pumps air through the cylinders for cooling. Therefore, the engine can run without coolant and produces about 40 hp max in this mode, so its enough to get you home slowly.

Personally, I think your engine damage was not related to your running out of coolant.
As noted above, these engines have a head bolt problem where, if driven enough the head bolts will eventually pull loose and low the gasket.
147k miles is pretty average mileage for this problem to occur.

thanks for comments ya was thinking
just head bolt