Volvo Repair: intermittent sluggish transmission Volvo S60, auto diagnosis, volvo s60

Question
QUESTION: 2001 Volvo S60 2.4T with 59200 miles. With 'cruise control ON' or manually using foot for acceleration, I notice a cyclic (every 30 seconds or so) 'sluggishness' of the transmission when driving on a 'non flat' road (up hill).

Let me explain what I mean by 'sluggish': it feels like "DOWN SHIFTING" ...but this is VERY subtle, not like the car jerks, but you 'feel' the car slowing for a half a second before it picks up.

Drove the car without the 'cruise ON' to see if it was something to do with the cruise control, but same behavior.

Any guidance is much appreciated.

ANSWER:   Nalin, possibly the A/C compressor is cycling? O'wise maybe a lazy oxygen sensor.

Mark

---------- FOLLOW-UP ----------

QUESTION: Thank you so much for the reply, I was thinking of taking it to a dealership but wanted to understand 'possible' causes so if they tell me something I'd know if it make sense or not.

The sad part is that ALL the dealerships around where I live has really bad reviews when I google them and look at their reviews! so...looks like they are going to take me for a ride anyways? Any suggestions on this?


Answer
  Nalin, simple. Ask for a gaurenteed diagnosis. In other words, "are you sure that will fix it?" Ask, if that does not fix it then what? Will I be charged for parts and labor that do not solve the problem? Will ypu remove the wrong parts at your expense and install the proper ones to fix it? (Auto diagnosis is hard and no one, not even myself gets it right the first time, everytime. But I never charged for what did not fix a vehicle.
  Be very cautious of this phrase, "well, we'll have to start there and see what happens." At times, (seldom) it is valid. A poorly maintained vehicle with no history can have multiple problems. Some people wait until it doesn't run before they have anything done. Then, that is the approach you have to take because there are so many things worn or out of spec., that have to work together to achieve the desired repair. You do not sound like that kind of a person. You obviously are paying attention to the way your car operates. That will save you money in the long run.
   My favorite phrase is, "you can pay me a little now, or a whole lot later." HTH

Mark