Trailblazer Rattling Noise

[RTTBLT1]

Ok, I think I will replace the Upstream 02 Sensor and go from there...but say the 02 Sensor is the culprit behind the slightly poor MPG and engine performance...

What do I make of the Rattle in my video?...which I haven't heard the noise since the video by the way

 

[Mooseman]

I didn't recognize the noise. But it's not doing it anymore so it would be near impossible now to pinpoint. Maybe it was a loose baffle in the muffler.

 

[RTTBLT1]

I didn't recognize the noise. But it's not doing it anymore so it would be near impossible now to pinpoint. Maybe it was a loose baffle in the muffler.

Ok, i was going to do the welding glove trick on it but never got the chance. So I figured I would get a Back Pressure Test...and it saved from purchasing a unneeded Cat.

On the 02 Sensors...I've always heard the Downstream 02 Sensor never needs replaced unless it's throwing a code or when replacing the Cat.

So tonight I think I will order a new AC Delco Upstream 02 Sensor and go from there. Update to come!

Thanks, everyone!

 

[cornchip]

Well....I have a GoPro but need to machine a mount to do a proper road test to get all the noises. For the time being, I threw the camera under the truck and gave it a little throttle in both drive and reverse with the brakes applied. Sounds a little abusive....but it replicates one of the sounds I hear. That sound is the loud metallic ping/pop. I still don't think it's in the exhaust....perhaps rear brakes or link arms??????. Dunno.

 

[Mooseman]

Sounds like the drive shaft getting pinged. Did you check the u-joints?

 

[richphotos]

Yeah, that does not sound like exhaust to me.

Right away when you put it into gear it pinged. I agree with checking the u-joints.

 

[cornchip]

I'm going to do a set of U Joint's Saturday and check the difference. Something I noticed Friday night has me wondering. Past couple of weeks I haven't done any highway driving. So I never get much past 50mph. Closer to 50 I can hear my exhaust rattle when I'm cruising or adding power. . It's much worse at 70....and doesn't matter if I'm in D or 3rd gear either. As soon as I let off the vibration goes away. The U joint's will be a good start. I check back in with the results.

 

[cornchip]

Oh, forgot to ask. Another noise I have is from the accessory belt . This week I did the tensioner and idler pulleys. The squeak persist and I think it the AC pulley bearing. Rock Auto doesn't list the bearing number, but I'd assume it can be changed out. Anybody have that bearing number?

 

[Mooseman]

There was a very recent thread about that:
http://gmtnation.com/forums/threads/very-noisy-ac-compressor.15949/

 

[cornchip]

AC clutch compressor bearing changed. Measured 35x50x20 (same as link....thanks) on my Sanden compressor. Easy job. On to the next job.

 

[cornchip]

It was the U joint as predicted from the 'pinging' sound it was making as well as the vibration. Thanks Moose.