What you need to know before you pull that head off


A few weeks ago, I wrote about buying a 1987 BMW 535i sight-unseen in Tampa, and how, when it arrived, the combination of valvetrain noise and rough running led to the discovery of a broken rocker arm. The action required was straightforward enough—pull the head, replace the rocker, reinstall the head—but the question soon became, “While the head is off should I take it to a machine shop for a proper valve job?”

This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2018/11/12/before-pulling-the-cylinder-head


Depends what your plan for the vehicle is. Selling, keeping for the long term or keeping for the short term. How much time and how much money to you have to budget? What ever the timeline or dollar amount is, expect twice that. There are always unexpected delays. ETA means estimated, not exact! Also, I would question anyone’s advice that is claiming to be a hack.


ms_julesy Depends on which sense of ‘hack’ the writer intends; the sense of a hack being a poor excuse for a mechanic, or the sense of hack meaning an innovative way to resolve a problem.

I probably shouldn’t speak for the writer, but I will hazard that he meant the latter sense!


There are straightedges, and there are straight straightedges. When checking for warp, make sure you have a good one, preferably made in USA, and not dinged up on the critical edge.


@bra356 - A worthwhile tip about making sure your straightedge is straight when checking items like this. Anything I have ever purchased that is meant for construction is merely straight-ish rather than the precision instruments that are available for more accurate endeavors.


Another great article Rob. Love these. Keep up the great work