Aloha! I just bought a 2004 suburban 1500 Z71 that had lifter tick. The entire top end of the engine was taken apart and new parts installed.
At first, the engine would idle fine but would occasionally dip to 400 and then the voltage would drop and the engine died. I replaced the alternator since I saw lights dimming at idle. Car rarely dies anymore; however, it still has a rough idle.
I can start up in the morning, idles great, takes off great, drives 40-50 miles to work and has great power across the rpm range. but occasionally when I come to a stop, it will idle rough (400-700) and I get a random misfire code. At the same time, my AC gets hot (weird noise coming from back of car ac area, seems like gas expanding), as well as my engine will start to heat up (220-230). If I give it gas, it goes back to normal, roughness is gone, ac gets warm and engine goes back to ~207. Are these all connected? I'm assuming low on freon, but not sure that would cause the other two.
TLDR: Symptoms
1. Intermittent rough idle, can be caused with AC on full power
2. AC will make a noise in the back of the car at idle and then blow warm air
3. engine temp occasionally heats up to about 220-230, but then goes down after I start driving.
I've replaced alternator and MAF sensor, both of which improved engine function. a bit stumped at this point!
