My '02 Blazer is having a problem when it runs cold. When I initially accelerate, the tach shows high RPM's before it shifts into second gear. It also sounds louder than normal. After warming up, it runs much quieter and smoother. However, when I drive into the mountains on the highway, maintaining a speed of 70 mph, and I get to a long 6 degree upslope I have to put the pedal to the floor. I lose power, it runs loud, my tach goes up to 4500 rpm and my speed will decerease to 50 mph until the road levels out. I realize that I should expect different performance during mountain driving, but nobody else around me seems to have a problem to the extent of my Blazer....Any thoughts?

 

Are there any DTC's set (check engine light on)? Even if the CEL is not lit, get the codes read and let us know what, if any, are present.

When was the last time a tune up was performed? Have you cleaned your MAF sensor lately?

When you say it gets loud, is it a fan type noise? If so, your fan clutch may be shot, causing the cooling fan to run all the time instead of slipping when not required.