02 WRX 4.5krpm hesitation

byron,

fill the tank with the highest octane gas you can find, then reset the ecu. do this by disconnecting battery terminal for a minute, with some draw on the battery (ie, have interior dome lights turned on). then, get back in the car, and drive fairly spiritedly.

if the hesistation comes back, it's a cause for more concern. otherwise attribute it to a bad tank of gas, with insufficient octane, which causes knock, which the ecu picks up on, and correspondingly reduces ignition advance and lower power. the ecu has many different "load cells" which cause the hiccup to be very localized along the powerband.

hth ken

I (and many others with '02 WRXes) have had this problem. If you have what we've had, it's bad electrical grounding. You'll find that Subaru inexplicably attached its grounding wires over painted metal -- not the best recipe for a good connection. The good news is that it's an easy problem to fix. Just undo the connections, sand off the paint, apply dielectric grease, redo connections and resume driving.

Good luck...

Meester Idunno wrote:

What happened to third and fourth gears?

I'm not quite sure - and I was a bit shocked that they had to replace all that stuff. I brought it in because it was occasionally grinding when I tried to shift into 4th. 1st and reverse were (and still are) a bit cranky, but they are not grinding. I would have to move the shifter back into neutral for a second or three before I tried a 2nd time, which always worked. Beforehand I did little things on my own like moving the seat up further to make sure the clutch was being pressed all the way in. It was. The dealer told me to bring it back in a few weeks - they ended up keeping it for 3 days, during which (among other wear items I had them fix) they replaced gears, synchros, and hub for 3rd and 4th. The problem seemed to be getting worse over the last couple of months. Still, it only happened one time in about 10. I do mostly city driving these days, so 4th gear use was a lot higher than with any other car I've used. I never noticed any problem with 3rd - I guess they saw something when the tranny was opened up. The 4th gear grind could happen under fast acceleration or during relaxed driving when I was shifting from 2nd directly to 4th or anywhere in between - it didn't matter.

The dealer was quite nice about things, and covered the tranny work under warranty, but they said they had to send the parts back to SoA to verify they weren't abused. I wish I had thought to ask to see them so I could see for myself what happened.

I'm not quite sure what a hub does - can someone enlighten me?

Byron

we've had, it's bad electrical grounding. You'll find that Subaru inexplicably attached its grounding wires over painted metal -- not the best recipe for a good connection. The good news is that it's an easy problem to fix. Just undo the connections, sand off the paint, apply dielectric grease, redo connections and resume driving.

Geez - the people who installed my stereo 9 months ago made sure to prepare the ground from the amps in the way you describe... but then again taking care of the little details like that is the reason I chose them in the first place. I wonder why Subaru did something silly like this. Where in the engine compartment is it? I assume you're talking about the wire going from the battery to what usually is a frame or body member?

I'll also try resetting the ECU with Ken's suggestion. Thanks to both of you. I'll try both things and report findings when I know something definitive.

_ Byron

we've had, it's bad electrical grounding. You'll find that Subaru inexplicably attached its grounding wires over painted metal -- not the best recipe for a good connection. The good news is that it's an easy problem to fix. Just undo the connections, sand off the paint, apply dielectric grease, redo connections and resume driving.

Geez - the people who installed my stereo 9 months ago made sure to prepare the ground from the amps in the way you describe... but then again taking care of the little details like that is the reason I chose them in the first place. I wonder why Subaru did something silly like this. Where in the engine compartment is it? I assume you're talking about the wire going from the battery to what usually is a frame or body member?

I'll also try resetting the ECU with Ken's suggestion. Thanks to both of you. I'll try both things and report findings when I know something definitive.

- Byron

I did as you said below. It worked perfectly - my WRX is back! I disconnected the battery, while I worked, so I assume the ECU was reset at the same time. I found that the connection near the battery seemed to have metal-to-metal contact, but the one near the airbox not only was painted over, but in my car a big glob of paint that probably prevented the star washer from fitting flush. Getting the paint off was not difficult, but getting the primer off required a metal grinding wheel for my Dremel tool.

Many thanks!

-Byron

we've had, it's bad electrical grounding. You'll find that Subaru inexplicably attached its grounding wires over painted metal -- not the best recipe for a good connection. The good news is that it's an easy problem to fix. Just undo the connections, sand off the paint, apply dielectric grease, redo connections and resume driving.

I really should check my grammar before sending messages... Yikes!