Some time ago, Tony and Sarah acquired a 2002 X5 3.0 that had some “miscellaneous” issues.  After initial inspection, the X needed all of the normal things: brakes, CVs, valve cover gasket, etc.  The customer then noted that the truck had been sitting for 3 years after a “severe overheat.”  A block check revealed that the headgasket had indeed been compromised and, after removing the valve cover, we confirmed that several of the headbolts had lost tension.

This issue is unfortunately common with the aluminum block/aluminum head M54 engines.  Cooling systems fail and even a minor overheat can cause the head bolts to pull the threads out of the aluminum block.  Generally, this means tossing out the old engine and replacing it with a remanufactured engine.  This route is not exactly cost-effective for a consumer.  In this case, the customer bailed out and sold the X5 at a very reasonable price to Tony and Sarah.

We have, on two other occasions, repaired these aluminum blocks using pinned, thread inserts installed into the block.  This requires a special jig and some expensive inserts, but its worth the time if it saves the expense of a new engine.

This weekend, Sarah flexed her muscles and tore the head off of the X5 to see just how bad things were in there.  The red dye you see is used to check for cracks, and fortunately, this M54 does not appear to have any at the moment.  The head is warped a bit, so we’ll send it over to the machine shop to true it up. Check out that head bolt!  That’s engine block on the threads of the bolt!

Stay tuned for more updates and a hopefully successful outcome!