so im having a problem with my car. i have no idea if its serious or not. but me and my friend have the same car, both 1998 honda civic's. one a dx the other ex. well mine has 91000 miles on it, and when i start it after it sits for a few hours in the cold. for whatever reason, it knocks excessively loud. and as soon as it runs for about 30 seconds, it goes away. it has plenty of oil and i dont beat on it. and my friends car, also does the same exact thing. could it be a rod knock or spun bearing? or is just valve noise? im afraid if i keep starting it in the cold it might cause the engine to blow. any suggestions???

 

What type of oil are you using in your engine? If you have a rod knock, it will be consistant and all the time, more loud on power pull then coasting. if you have a spun bearing, you will hear a loud scraping sound and a knock sound at the same time, it would be a horrible sound, enough to scare you.If you need a valve adjustment, it will should like a light tapping sound for a short time, then quiet. Sounds like a valve adjustment noise.

 

im using valvoline 5w-30 high milage synthetic. the mechanic at my work says its a worn bearing, when its cold the bearing contracts. when it heats up it expands. i refuse to believe it. it probably needs a valve ajustment though, as well as a new timing belt pretty soon. but the thing is, my friends ex has 157000 miles, its got lifter ticks and everything. and it just recently started doing it on his car too. would it harm the motor at all over long periods of time?