Hi Guys, I have an 02 Blazer (123k mileage) and in the past few days I have noticed a very low sounding "moan" or a "groan" type noise when I accelerate which is accompanied with a general feeling of power loss despite the fact that I can usually hit 75/80 mph easily. I've also noticed that from time to time when I accelerate the rpm gauge will go to 2.5 and some times it will struggle to hit 2. Sometimes I'll let my foot off the gas and coast down a hill and then hit the gas and the rpm needle will hit somewhere around 2 and then almost immediately fall a little bit. I have no idea what in the world this could be.

Now, I do have 2 codes which has prompted me to placing a thermostat replacement on the docket. I don't think there's any way these two could be related though. Any ideas?

Thanks!

 

It might help if we knew what the two codes are.

 

The codes would help that aspect of things.

As far as the "moan"/"groan", can you be more descriptive about possible locations for the noise? Is it coming from under you, in front of you, or behind you? Does the noise change depending on whether or not you are turning slightly to one side or the other and if so, which side does the noise level increase?

Have you checked your universal joints? Factory joints are sealed and cannot be serviced. Aftermarket joints can be greased. Telltale signs that the universal joint is going bad is a brownish dust around the rubber boot at one or more of the bearing locations (the outer portions of the cross).

As far as your observation of the engine RPM, this sounds fairly normal. Engine load and throttle position dictate gear selection and torque converter lockup which both affect the engine RPM. If the transmission stays in a higher gear as you try to accelerate, it will seem slower than if it were to drop down a gear under the same circumstances.

 

I can't remember the codes off the top of my head and the paper I wrote them on isn't on me at the time. The guy at Autozone (I got it scanned at Autozone) stated that both were thermostat related/coolant. I can't remember

The noise, well I'm not the most knowledgeable guy when it comes to these things but I would have to say it's coming from in front of me. Doesn't make much difference in terms of turning in either direction that causes the moaning/groaning sound. I'm not even sure if that's the proper way to describe it lol. It comes and goes (example: last week it was fine until the rain and cold came -- after that it was pretty much constant) which doesn't help me when I have somebody take it for a test drive and say "Nothing's wrong!" lol. Clearly...

Any chance it could be bushings on the left front? That was part of another upcoming maintenance. Just trying to eliminate possibilities.