In my 2003 Toyota 4runner SR5 the open engine hood falls without warning. A small hydraulic piston automatically holds the hood open when the hood is lifted. There is no rod or other mechanical device to hold the hood open, just the piston. The hood stays open for a few minutes, then quietly falls, at first very slowly for a few inches, then rapidly enough to possibly cause serious injury to a person leaning over the open engine compartment. The hood is fairly heavy probably due to the thick and heavy fiberglass insulation. The piston worked properly until about early 2009 when it started occasionally falling, now (April 2010) the hood falls after a few minutes every time the hood is opened. Since this started happening I've been using a wood stick I cut to size to hold the hood open when I need access. Now I'm going to have the piston replaced but I'll ask for the removed parts back in case they need to be examined. Even with the new piston, though, I intend to use the wood stick as a safety measure. I just don't trust the piston design since it apparently requires perfect sealing to maintain the lifting force. Also, according to my independent auto repair shop that does mainly Toyota's, this is a frequent enough problem that their repairmen always brace the hoods open when working in engine compartments. Thanks.

- Littleton, CO, USA