Bad mpg... Cleaning out carbon?

[BackroadBomber]

I've recently been thinking about running some seafoam through my rangers engine to clean out some carbon in the intake manifold and inside the engine. Would this improve fe or hurt it? I thought that with more carbon on the pistons, the compression ratio is higher and that's better for fe? I'm pretty much grasping at straws here I loaned the truck to my buddy for about a year, and when I got it back I fixes the egr tube (it was broken), the dpfe sensor, and put manual steering box in (pump was shot), and got an alignment. Everything that he broke is now fixed and its still not getting the mpg it did a year ago.

[JRMichler]

Have you checked the spark plugs? The compression? Thermostat? Bad cam lobe? Any of these, along with other things, can cause the mileage to drop.

[BackroadBomber]

I've checked the plugs, it has terrible compression but it always has, don't know what you mean by check the cam but I just remembered that my timing belt is loose. It has about 1 1/2 inch of play when I press on it, but the timing's steady ( I checked it with a timing light) maybe ill replace that next week and see how she runs. It's the original timing belt from 1993 182,000 miles ago so it's probably time for a new one anyways

[D.O.G.]

Originally Posted by BackroadBomber

I've recently been thinking about running some seafoam through my rangers engine to clean out some carbon in the intake manifold and inside the engine. Would this improve fe or hurt it? I thought that with more carbon on the pistons, the compression ratio is higher and that's better for fe? I'm pretty much grasping at straws here I loaned the truck to my buddy for about a year, and when I got it back I fixes the egr tube (it was broken), the dpfe sensor, and put manual steering box in (pump was shot), and got an alignment. Everything that he broke is now fixed and its still not getting the mpg it did a year ago.

Cleaning carbon out of your combustion chamber is a good thing to do.
That carbon can make your piston rings stick, adversely effecting compression, increasing blow-by and decreasing available power.

I haven't used Seafoam, but ran a home made water injection system for a few weeks on a previous car to clean out the carbon.
I did see better fuel consumption after it.

[RobbMeeX]

I found good results from AutoRX.

[RobertISaar]

Originally Posted by BackroadBomber

I've checked the plugs, it has terrible compression but it always has, don't know what you mean by check the cam but I just remembered that my timing belt is loose. It has about 1 1/2 inch of play when I press on it, but the timing's steady ( I checked it with a timing light) maybe ill replace that next week and see how she runs. It's the original timing belt from 1993 182,000 miles ago so it's probably time for a new one anyways

timing light will not show anything related to the timing belt. you're mixing ignition timing(light) with valve timing(belt/cam).

timing belts generally don't last to 100K miles, let alone 182K.... 60K is a good interval for most engines.

a stretched belt will essentially act like a retarded cam, lower RPM power/economy tends to suffer while higher RPM benefits.

[redneck]

All the above, plus check for any vacuum leaks. You may also want to replace the 02 sensor(s) if its never been done.

Unfortunately, there are many engine factors that can affect fuel economy.

As far as removing carbon, you can use a plastic water misting bottle. Bring engine up to full operating temp. Remove intake piping from intake manifold. Set to high idle and squirt (mist) water into engine intake opening. A pint or so should do the trick.

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[Jakins]

I seafoam'd my civics couple weaks ago. Felt a little more throttle response. The smoke how is funny as hell!!!

[mcguire]

Originally Posted by redneck

As far as removing carbon, you can use a plastic water misting bottle. Bring engine up to full operating temp. Remove intake piping from intake manifold. Set to high idle and squirt (mist) water into engine intake opening. A pint or so should do the trick.
>

I tried this last weekend with my F-150, with poor results. If I removed the pipe from the throttle body, the engine died, presumably because the intake air sensor was no longer seeing the airflow. (?) If I disconnected the intake from the filter box, the engine died when I sprayed the water in, presumably because it was getting on the airflow sensor.

[RobertISaar]

with MAF vehicles, it's a bit more tricky, but i've always been able to pull the vacuum line for the brake booster and "pour" in that way....

notice: "pour", do NOT feed any liquid into an engine at a high rate, you can cause a hydrolock condition and engine replacements are not cheap.