'99 Montana broken camshaft

'99 Montana 3.4 with a broken camshaft. Is this a common problem or is this kind of rare? What are most common causes?

It's a semi-common problem if the engine has been allowed to continue to run with a leaking head/LIM gasket and antifreeze gets in the oil. In other words, it's common if vehicle maintenance was neglected.

we see a few now and then!

oil is free of antifreeze. appears to be fairly clean. I really don't want to go to all the trouble of putting another cam in if there is a more major problem that caused it to break in the first place. It ran fine, was parked one night, and failed to start the next morning. I don't mind spending the money to put a cam in it, I just want to be sure thats all it is.

Been there done that at about 70,000 miles with 1999 Montana. Replaced with a marshall rebuilt engine from Napa at a price of $1800. Installed myself so I saved the installation costs. Rebuilt motor has about 34,000 miles on it now. Good luck.

My engines did the same thing. I say engines because out of 3 vans, all 3 had the heads rebuilt and two cam shafts broke within 5k miles of the rebuild. My engine reman guy said every core engine he takes in has bad cam shafts, either snapped or ready to snap (bearings shot).
Must be true that the oil gets fouled with anti freeze and eats the bearings.

IF I were in your place with the bad cam I would just go ahead and swap out the whole engine--its less work and you get a warranty.

Last I checked you can get the rebuilt for less than 2k and it has a 4 year, 100k warranty.

These come out of St. Louis