2008 OB engine unicorns

[castiron]

2008 subaru OB 2.5 5 spd manual w/ 48k miles.

yesterday my wife reported something she described as a "hickup" or "engine bump", while maintaining vehicle speed. So lower RPMS 2-3k range without a lot of throttle. It happened several times on her drive. The engine was warm too. I did not ask her hour fast she was going but I beleive it was slower speeds since it was snowing hard in Boise and the roads were a mess.

it sounds like an engine misfire to me but there is no check engine light on.


On another note over the past year or so, on a very rare occation, when coming to a stop using the brake and the clutch depressed, I have noticed that the engine speed dropping reallly low, well bellow idle but it picks back up pretty quickly and goes to idle.


any ideas? i think i still have the power traIn warrenty on it....

[Shadow 1100]

Sounds like ignition coils,check for carbon cracks.

[1 Lucky Texan]

might try a scanner to see if there is a 'pending' code. freezFrame data might pick up on some odd fuel trim issue.

but , 'tune-up' type stuff might be a good idea - check the plugs, new plug wires, seafoam throttle body and half can/can in the tank, PCV valve.

[ScoobyRu]

I have exactly both problems. The engine dipping happens for a couple of days after I unplug the battery. The engine stuttering seems to happen more when it's wet outside. Very interested if you find a solution.

I plugged my car into my laptop and ran FreeSSM. Using the Factory Service manual for an '09 (Mine is an '06), nothing jumped out at me. A couple of values seemed to be a little over or under, but nothing alarming. My main concern is that my AF Learning isn't 0% at idle like the manual states it should be.

[castiron]

Originally Posted by st3mpy

I have exactly both problems. The engine dipping happens for a couple of days after I unplug the battery. The engine stuttering seems to happen more when it's wet outside. Very interested if you find a solution.

I plugged my car into my laptop and ran FreeSSM. Using the Factory Service manual for an '09 (Mine is an '06), nothing jumped out at me. A couple of values seemed to be a little over or under, but nothing alarming. My main concern is that my AF Learning isn't 0% at idle like the manual states it should be.

that freessm looks BA. I'll have to get it going! I'd be interested to find out more about your setup.

[1 Lucky Texan]

Originally Posted by st3mpy

The engine stuttering seems to happen more when it's wet outside.

isn't this often a high voltage problem? plug wires or coil?

shadow100 might have got it right. Sometimes a mister bottle of water sprayed at the idling engine at night will show arcing near a bad wire or coil.

[DavidPeab]

++ 1 Lucky Texan. First culprit: coil, due to symptoms.

[mandarin]

I didn't notice, 2.5i or XT?