Hello,

I am new to the forum and also to owning a Blazer. I bought a 2004 with the 4.3L Vortec that hass 55,000 miles on it. Overall, the truck appears to be in good shape, however there a re a few things of concern for me...hoping you all could help.

First thing, because the truck has the mileage it has and I do not know the maintenance history, I thought it a good idea to change the transmission filter. Now, it seems that the shifts have changed a little and was wondering what the typical shift points should be (RPM wise).

Also, I have this funny noise that is heard when I get on the fuel. Almost sounds like a bunch of bags under the truck being crumpled, but it is only apparent when I hit the fuel and in gear while I am in the truck. I had the guys look at it and they used the stethoscope....they noticed that the flange on the right side exhaust manifold and pipe had welds on it. Said it seemed to be in that are and a possible exhaust leak. Any thoughts? It does not have that typical popping sound.

The problem I have is that it can hear the sound under the truck when I climd there and I hear noise in the area of the oil pan and the bell housing. Hoping it is not in the tranny...already went down that road with another vehicle. Possibly just the noise resonating through the motor?

What are common sounds these trucks make? I have a service appointment Monday because I still have a bit of a warrnaty left, but I really need some thoughts to go in there with so they can take care of it.

Any information would be great....


Thank you

 

Your transmission will shift at different RPM's depending on how slow or fast you are accelerating. So, their is no specific shift points.

As for your noise under the vehicle, I could only suggest to inspect the catalytic converter. Mine had to be replaced and made similar noise to what you describe. The materials inside the converter can separate and make a rattling noise.

Let us know what you find out and good luck!

 

So, first I apologize for the length of time in getting back to this thread. The truck has been at the dealers shop for about 5 days and they finally think they found out what the noise was. I was told that it was in the 4 wheel drive and that it was coming from the transfer case. They also said that Chevy has had issue and that they needed to see what the deal was.

My wife then called and spoke to the desk man that stated that they needed to order a flywheel and it should be in this Tuesday.

Any comments, does anyone have any experience with this and also thoughts on if this could be the cause of the noise.

Thank you guys

 

Well, it has been about 3 weeks that the dealer had the vehicle and they FINALLY found the problem. After first changing the belt tensioner, then the flex plate and for safety sake the putting a new tourque converter, the truck still had a noise. More digging finally revealed that it was the timing chain tensioner. Replaced it and did all the service and the vehicle is back in my posession.


HOWEVER!!! I was driving it for the first time today and it seemed as though the tranny may have slipped. I semed to have gotten a "flair" between I think 2nd and 3rd. Could this be because of the work they did and air in the system or something like that? Before they had the truck, I had the tranny filter and fluid changed because the truck has about 56,000 miles on it and was not sure if it was ever done. Also, the people that did the change said it looked fairly clean and did not appear burnt or had any metal other than normal.

I know nothing about these transmissions. Are they known for any issues? Do they have any "quirks"? What is their reliability? Any help is greatly appreciated.


Thank you

Carl