Please Explain This Vehicle Description

I found a 1984 BMW for $500 on The seller admits that it doesn’t run, but here’s something interesting in the description:

I can buy a timing belt at Auto Zone™ for $15.99, but this bit about “interferance engine” confuses me. What does this mean? I’m assuming it means that the $15.99 timing belt from Auto Zone™ isn’t going to help me…


It’s not good.

It means you’ve got one hell of a mess to fix. An “interference engine” is one in which the valves and the pistons can come into contact if the timing gets badly out of whack. There is a good possibility of some serious damage to the engine - anything from bent valve stems to damaged pistons, maybe even the main bearings screwed up if it happened at high speed and the valve got really jammed into things hard and often before the guy got the motor stopped.
If you decide to buy it, add the cost of a complete overhaul to the $500. You may get away with less, but then again you might not.


A broken timing belt is a good sign that the car was never properly maintained… Figure the motor’s toast, and the rest of the systems are probably close to death too. And the cost of the parts will make your head spin. I’d look harder. A lot of BMW owners are fanatical about maintenance, especially the BMWCCA set.


Bent valve, probably.

I wouldn’t bother if I were you.