I have a 2002 GMC Sonoma Reg. Cab with the 4.3 engine and 5 speed transmission, along with the ZQ8 suspension. Other than regular maintenance, I have not had any of the problems that other people have said on here. To me, it's a great little truck. I have 134,000 miles on it, and it still gets as good gas mileage as it did when it was new.
Mine is a V6, SLS Ext Cab, bought in 2004 and it had only 29,000 kms.
Just before the warranty expired I had to replace the left upper ball joint. Had transmission fluid changed at 80,000 kms.
On Dec 14, 2010 at 103,000 kms the transmission failed. I had the transmission rebuilt and plan to sell the truck in early spring. The truck did serve me well but disappointed that the transmission failed at only 103,000 kms. To me that's not very reliable or dependable.
I have a 2002 GMC Sonoma ZR2. It has just over 170,000kms, and up until recently, it has been an excellent truck.
Antifreeze started leaking pretty bad about a month ago, so I had the intake gasket replaced. Directly after receiving it from the mechanic, I noticed it drove quite sluggish, in the sense that it shifts gears sooner than I remember. As well, it won't kick into the passing gear, ever. It's annoying and frustrating going up a hill, and not being able to get it over 2900 rpm, or have it kick down a gear for more power.
My mechanic doesn't seem to know what the problem is, and says the truck is fine.
Advice would be much appreciated.