changed the water pump (which was a pain) Instructions said to take NEG side off of Battery. When job was complete, there was a rough idle with code po300. I took off Throttle body and cleaned it with sensor safe throttle body cleaner, re-installed and same rough idle. Reset code no change. Started car and let idle and drove around block to get normal engine temp and check for leaks. Water pump job OK. Cannot get idle back to normal. I read the computer has to relearn the clean throttle body position. I am wondering if when I put the new water pump on as I tighten the pulley, it rotated the crank. Would this mess with the variable timing? I assume the computer would know. No other codes. HELP!!

I bought this car for my son to go to college. When I first bought it had 98,000 miles. I did a full tuneup, replaced fan clutch, new water pump and flush, new battery, new good year tires, new brake and rotors front and rear, recharged the air condition system, cleaned the throttle body, new sway bars. Really ran nice!

Now it lacks power, stalls in first gear, transmission whines, feels like it skips when in gear, idles rough and doesn't have any power. Went to give it another tune up plugs look like new in fact is in great shape. Had to replace the oil pressure switch but still give low oil pressure after 20 miles. I have been an aircraft mechanic for 30 years and cannot figure this car out!

I believe it may have a bad oil pump and computer and possibly transmission problem! Going this weekend to buy him a VW Passat and limp this piece of junk in to the dealer! This whole car should be a recall! Since GM had taken bail out money and moved their factories overseas they can take all of their junk with them! I will never ever buy a GM product! I have nothing but Toyota and VW products at least they care about their products!! And my Denali Yukon went in on trade for my Toyota tundra . No more GM junk for us!

I am so disgusted with my Chevy Trailblazer. Mid-Sept 07 we had the transmission replaced, then a week later the clutch fan went out. I had much phone contact with GM Customer Service where they implied they would help cover the expense of the clutch fan. Only to find out later that GM expects Chevy owners to cover their own expenses once you have some mileage on your vehicle. Even though the clutch fan is a very common occurrence, they said they haven't had many complaints. I told them this should be a recall part. They disagreed.Then a week later, the catalytic converter failed. I couldn't drive over 30 mph. In the course of 3 weeks, my Trailblazer was in the repair shop 75% of the time. What a piece of junk! No wonder consumers are buying Toyota and Honda! My next car will NOT be a GM if I can help it!!