2000 Z71 Gurgling Noise

[dougmac]

First, I’d like to say thanks for the great information that you give so freely. It takes a lot of time to respond to all of the request that you get and I appreciate reading them all.

 

I have a 2000 Z71 with a 5.3 it has 75,000 miles on it and since it was new, at times I hear a gurgling noise coming from under dash. It sounds to me like it is possibly coming from the torque converter. It seems change with engine load and RPM.

 

I have head some people complain about the heater core gurgling and I think this may be what they are talking about. I don’t think the heater core is the source and I have never had any problems with the cooing system. I haven’t ever had to add any coolant

 

I am not too worried about it, just curious about what may be causing it. I wonder if it might be the “Driveline Vibration/Growl” that TSB #99-07-30-024 addresses. Our auto shop just got a new MasterTech so I may be able go over and install the latest PCM update and see if that cures it.

 

Doug

[99silveradoz71]

The heater core will sound more like an air type noise vs. a growling. I had that for a bit after the dealer did a water pump replacement.

[GM-Tech]

I hate to sound like a broken record, and I may just have to put this on a macro so I don't have to type it each time

 

Noises are often among the most difficult things to find and fix. It's hard enough to find some noises when it's right there in front of you. Doing it over the internet based on someones noise terminology that may not be the same as mine makes it even more difficult. I've had people describe noises in excruciating detail and I have no clue what they're talking about. But then I hear it and go, "Oh THAT! I know exactly what that is." Hearing a description of a noise and hearing the noise under the conditions in which it occurs is the difference between night and day.

 

You said it was a "gurgling" noise so I don't know if doing the update that takes care of a "growling" noise will help, but if you have the capability to update the PCM, I say go for it. It couldn't hurt!

 

You could temporarily clamp off one of the heater hoses to elminate the heater core as a possible source of the noise.