On New Years Eve 2015, my household and I had been driving eastbound down the Ohio turnpike in my beloved 2002 Saturn L300. Every part was tremendous till, simply previous the Route 250 exit, the IP lit up like a Christmas tree and the engine out of the blue misplaced energy. Luckily, I used to be capable of coast to a secure spot on the shoulder. Sadly, that was the start of a depressing ordeal that lastly ended with me discovering that the Saturn’s timing chain had damaged and the engine was mulched.
That technology of Saturn was powered by GM’s L61, a 2.2-liter, twin overhead cam, inline 4 that Common Motors utilized in a bunch of its small automobiles within the early aughts. Now, if you understand something about GM engines, you would possibly know that the L61 is an interference engine. That implies that when the engine is operating, the valves and the pistons occupy the identical area. They do not do that on the similar time, clearly, and so they’re saved from doing so by the timing chain. If the timing chain breaks, nevertheless, you get a state of affairs that we within the business like to explain as no bueno.
By no means the twain shall meet
When a timing belt or chain breaks, it severs the hyperlink between the crankshaft and the camshaft(s). This causes the valvetrain to cease shifting whereas the crankshaft and pistons proceed to work. With the valvetrain stopped, a number of valves shall be caught within the open place, and these open valves shall be protruding into the area the place pistons go. The pistons then come up on the compression or exhaust stroke and slam into the open valves. It will probably occur a whole lot, if not hundreds, of instances earlier than you may get the engine turned off, and by that time, the injury is already executed.
What sort of injury? The actually nasty, costly form of injury. Getting battered by a piston just a few thousand instances will bend the open valves or snap their heads off. The piston itself could get gouged and even punctured, and any particles from damaged valves can injury cylinder partitions. In some very unfortunate circumstances, the connecting rods themselves would possibly get broken. All of this occurs within the blink of an eye fixed, and it renders the engine ineffective till it is repaired.
The great factor is that this type of carnage is preventable. Each automobile, whether or not it has a timing belt or a timing chain, has set intervals for timing belt or chain upkeep and alternative. Positive, changing a timing belt or chain is a ache and may be dear, nevertheless it’s cheaper than changing an entire engine or scrapping the automobile. Oh, and my previous Saturn? I ended up slapping a salvaged engine in it and driving it for 4 extra years till I traded it in for a Kia Soul, one of many smaller vehicles readers stated America ought to love.
