I have a 98 Civic that recently, upon cold starting in colder weather, the engine emits a loud rapping noise from 10 to 45 seconds. Eventually it goes away. Does anyone have any suggestions to cure the issue. Different oil, additive, valve adjust? Thanks.

 

mileage???

 

124K

 

Your going to need to check oil pressure mechanically....

Possibly a clogged oil pickup screen causing low oil pressure

 

could possibly need a valve adjustment as well

 

Thanks, guys. 1st step, I'll try the valve adjustment. It's been about 70K miles since I last adjusted the valves.

 

What about belts? Pulleys? Are you sure it's internal?

 

It sure sounds internal, metallic rap, lack of oil, stuck valve type of sound. Belts and timing belt were replaced at 104K. Noise disappears after several seconds. It only occurs in cold weather on a stone cold startup. I live in the northeast. The colder it is the longer it lasts, but again never over a minute in duration. This is a new phenomena this year, it never happened in past years. The last two years the car has been driven 5 days a week on a 70 mile round trip highway commute, prior to that it was driven less frequently.