Low Compression

[Dutch]

Hi everyone,

I ran a compression test on my engine (KA24DE) and the results showed I had low compression, which would explain my poor gas millage and acceleration.

Cyl#1 145 PSI

Cyl#2 140 PSI

Cyl#3 140 PSI

Cyl#4 125 PSI (A 20 PSI drop scares me)

The specification for this engine showed min of 149 PSI and a max of 179PSI. My first thought would be worn compression rings, but I want to hear what you guys think? The engine only has 70,000 miles on it. I did forget to press down the gas pedal when I did the test (Was in a time crunch and forgot) would this cause false readings?

Thanks

[Rollingcarshopaz]

For best accuracy you should perform the test on a warm engine and wide open throttle, however in my experience this doesn't significantly affect the readings. Remove all the plugs, squirt a small amount of oil into each cylinder, crank the engine over for about 10 seconds, then recheck. If compression comes up a good amount then you are looking at worn rings. If about the same, then a valve sealing issue. Since you're low across the board I would suspect rings, but at any rate that sucks with the low mileage.

[frontier bob1]

what is your mpg . also lucas makes a additive to add to the oil to improve gas milage