Very rough starting and knock at idle

[venom42]

Basically, when the car starts it sounds like it is only firing on a few cylinders. After a couple of seconds it smooths out and begins to idle. However, the idle is a little rough (slight misfire). The cylinder closest to the firewall has also been knocking intermittently, but only at idle. It seems to be more frequent when the engine is hot. The knock is high up in the engine. The valves were just adjusted. New plugs/wires/cap/rotor. From looking at the plugs it is running rich. My mechanic friend said it sounded like a wrist pin, and would likely be ok. I am less optomistic. I only get about 17 mpg. Could it be fuel related (bad injector)? Spun bearing? Any help is appreciated.

[beandip]

If you have a bad wrist pin to the point of it rattling as you said , it wont be alright . For one thing 17MPG is way off , unless you have your foot in it all the time . Post a question for the running rich problem . There are members here that really know injection and can help. I am not one of them. Sorry But a bad wrist pin or a rod bearing are nothing to fool with and needs to be addressed. Just dont run to high revs untill you figure out the knock you are hearing . It could be caused by something else but from your description I am not optomistic. Gary

[venom42]

I do drive her hard, but I used to get around 20 mpg when I first had the car. I am thinking that a major engine failure is on its way soon. I have been looking at some used or rebuilt engines, so I am prepared. This car is my daily driver, so I cant afford to have her down for long. I am hoping it is not as bad as it seems, but preparing in case it is.

[venom42]

I forgot to add that it does not knock every time I drive it. Would a failing injector cause this if it were occasionally sticking open or something? The knock is just below the head, not down in the engine. Plus, if it were a bearing it would knock all the time right? If you pull the plug wire the knock becomes constant. I dont see how it could be related, but it has also developed an exhaust leak about the same time the knock started. Figured I would mention it just in case.

[beandip]

If the wrist pin fails you will loose the block and crank most likely and the head vary likely . So if you want to sweep up the engine and dump it in a box . Keep pushing it. you have more to worry about than bad gas mileage .