4.0 sohc feels low on power

[White_4x4Ranger]

Lately I have noticed that the 4.0 in my 2003 ranger 4x4 feels sluggish, and it getting terrible gas mileage, around 11 mpg. Any ideas what it may be? Engine sounds good ( no ticking or annything of that nature) and doesn’t have any issues. 187k miles.

 

[rusty ol ranger]

Check engine on?

 

[White_4x4Ranger]

Nope.

 

[rusty ol ranger]

Put a vacuum gauge on it...i cant remember exactly what the readings would be...but im wondering if you got a plugged cat

 

[White_4x4Ranger]

I’ll look into that. I just put some injection cleaner in the tank just to see if it does anything. Thanks.

 

[Uncle Gump]

Fuel mileage drop in the winter. My 4.0L gets 16 to 18 in the summer and drops to 13 to 15 in winter. Fuel blend... warm up time adds up to the lower numbers. 11 mpg is pretty low.

You ever smell fuel?

Does it blow black smoke?

Low on power is another thing. You check for throttle cable stretch?

Also... have you ever changed O2 sensors?

 

[White_4x4Ranger]

Also, would the check engine light come on if it was running rich or if some of the sensors were dirty, like the mass air flow?

 

[Uncle Gump]

It would if it couldn't compensate.

 

[White_4x4Ranger]

Fuel mileage drop in the winter. My 4.0L gets 16 to 18 in the summer and drops to 13 to 15 in winter. Fuel blend... warm up time adds up to the lower numbers. 11 mpg is pretty low.

You ever smell fuel?

Does it blow black smoke?

Low on power is another thing. You check for throttle cable stretch?

Also... have you ever changed O2 sensors?

Good to know that it might just be the weather. I’m in central Washington and it is around 30-40 daily and gets into the 10-20 at night. Fahrenheit by the way. No black smoke, a fair amount of white stuff tho, might just be steam or whatever else comes out of tailpipes in the winter, just like other cars. I bought the truck used from its first owner, not sure if they ever did O2 sensors. I haven’t checked the throttle cable will do that though.

 

[White_4x4Ranger]

Ok. That was the first thing I thought of when I noticed the lack of power and crappy fuel efficiency. Could a rich condition cause a drop in power?

It would if it couldn't compensate.

 

[Uncle Gump]

Yes it can...

 

[rusty ol ranger]

Good to know that it might just be the weather. I’m in central Washington and it is around 30-40 daily and gets into the 10-20 at night. Fahrenheit by the way. No black smoke, a fair amount of white stuff tho, might just be steam or whatever else comes out of tailpipes in the winter, just like other cars. I bought the truck used from its first owner, not sure if they ever did O2 sensors. I haven’t checked the throttle cable will do that though.

Its not losing coolant is it?

 

[White_4x4Ranger]

Not that I know of. I haven’t seen any spots beneath it and it doesn’t overheat

Its not losing coolant is it?

 

[rusty ol ranger]

Not that I know of. I haven’t seen any spots beneath it and it doesn’t overheat

Just trying to rule out a bad head/head gasket. Chances are the steam is just condensation but id check your radiator and overflow tank to make sure its full

 

[White_4x4Ranger]

I hope it’s not a bad head or head gasket. Ive worked on small engines before and have done a top and bottom end on a Kawasaki dirtbike but I’m really intimidated by a truck engine. Not so much by the engine itself, but more so all the other crap in the engine bay I’d have to deal with.

Just trying to rule out a bad head/head gasket. Chances are the steam is just condensation but id check your radiator and overflow tank to make sure its full