On New Years Eve 2015, my household and I had been driving eastbound down the Ohio turnpike in my beloved 2002 Saturn L300. The whole lot was nice till, simply previous the Route 250 exit, the IP lit up like a Christmas tree and the engine all of the sudden misplaced energy. Thankfully, I used to be in a position to 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 era of Saturn was powered by GM’s L61, a 2.2-liter, twin overhead cam, inline 4 that Normal Motors utilized in a bunch of its small automobiles within the early aughts. Now, if you realize 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 house. They do not do that on the identical time, clearly, and so they’re stored from doing so by the timing chain. If the timing chain breaks, nonetheless, 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 transferring 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 house the place pistons go. The pistons then come up on the compression or exhaust stroke and slam into the open valves. It will seemingly occur a whole bunch, if not hundreds, of occasions earlier than you will get the engine turned off, and by that time, the harm is already carried out.
What sort of harm? The actually nasty, costly form of harm. Getting battered by a piston a number of thousand occasions 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 harm cylinder partitions. In some very unfortunate circumstances, the connecting rods themselves would possibly get broken. All of this occurs within the blink of a watch, and it renders the engine ineffective till it is repaired.
The nice factor is that this sort 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. Certain, changing a timing belt or chain is a ache and will be expensive, however it’s cheaper than changing an entire engine or scrapping the automobile. Oh, and my outdated 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 mentioned America ought to love.
