fuel consumption, engine humming and whistling

1999 HONDA CRV
162,000 MILES • 4 CYL • AWD • MANUAL
Avatar
TROJAN2131
  • MEMBER
  • 1 POST
i'm experiencing excessive gas consumption, 7-8 mph less than normal. what could be contributing? I have been hearing a high-pitched humming or whistling from the engine, I think, especially when I'm accelerating at higher speeds. The check engine light is always on. I think I feel a misfire when it's idling, but i just changed the spark plugs, wires and distributor cap less than 2 years ago. There are also fluctuating idling speeds. I'm not sure if the problems are connected, but what might some of the possible problems be? the diagnostic codes are P0300-P0304, all five of them.
Jan 11, 2011 at 8:55 PM
Advertisement
Avatar
KHLOW2008
  • ✓ASE Certified Mechanic
  • 41,814 POSTS
  • ASE Certified Mechanic
When the CEL is turned on all the time, fuel consumption and performance would be affected.

P0300 - P0304 are misfiring codes and it could be anything from bad spark plug and/or wires to faults with fuel pressure.
2 years is a long time and anything from contaminations to failed components can cause the misfire.

It is not possible to comment on the noise as its source is not clear.

Jan 14, 2011 at 5:54 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.