Subaru Outback 2001 transmition rough spot

Our 2001 OUTBACK D"BUCKS" AT ABOUT 1300 RPM AND BETWEEN 30 TO 40 MPH. THE ENGINE REVS FINE, IDLES FINE, AND HASD O2 SENSOR REPLACED RECENTLY. HAS 11500 MILES ADN WAS REBUILT DUE TO BAD HG AT ABOUT 90000. ANY SUGGESTIONS??

SORRY, I MEANT 115000 MILES ON IT

Why do you assume that this is a transmission problem?
It is just as likely, if not more likely, to be an engine-related problem.

Please tell us date and the odometer mileage when the spark plugs, plug wires, air filter, fuel filter, and PCV valve were last replaced, and also give us the history of transmission fluid changes for this car.

Also, is this a 4-cylinder Outback or a 6-cylinder model?

Thanks for the response. I need to do some “homework” to respond to your questions. I know for a fact that most of the wires, plugs and transmission fluid are original. I will make sure that the fuel filter and
PCV valve replacement are within recent timeframe, or will replace them now. It is a 4 cylinder with 115230 miles on it, and had the upper end redone at about 90000 miles.

Well, even though I still think that the problem is engine-related, I have to say “good luck” with the transmission. With 115k on the odometer, the fluid should have been changed 3 times already, meaning that the trans is likely living on borrowed time.

And, those plugs may wind up taking part of the cylinder head with them when they are removed, simply because they have been in there WAY too long. Have the plugs replaced by someone who knows his way around Subaru engines and if you are very lucky, no harm will come from their removal.

Bring the car up to where it should be on maintenance, and your driveability problem may be resolved.

Thanks, again. I have been informed that the transmission fluid had been changed, but we are bringing everything up to speed anyway. I’ll take your advise.

Did homework, and the tranny had been flushed twice, and filters had been changed. Plugs were changed twice before, but someone changed NGK to Denso. We had O2 and knock sensor changed, tranny flushed, NGK plugs installed, new pcv and fuel filter also. Purrs like a kitten, and the check engine light is now gone. Thanks, again, for the advice

I’m very glad that the driveability problem was resolved.

However, I have two comments:

First, in regard to your update, “the check engine light is now gone”, are you aware that you never revealed the presence of an illuminated CEL in any of the preceding posts when I (and possibly others) were trying to diagnose the problem for you? Leaving out information like this is not very helpful.

A second point that is really vital is–
Has the timing belt been changed?

If the car still has the original timing belt, it is overdue for changing by 10k miles/2 years.
If it has not been changed, when it snaps you will have the ultimate in driveability problems–namely an engine that has self-destructed.

If the belt has not been changed, have that done, along with the water pump, serpentine belt, and all belt tensioners immediately in order to avoid REALLY big repair bills.

yes, the belt was changed 25000 ago. This is my first “forum”, and I have learned a lot about the process.

I’ll do better the next time!!