Mechanics

CHEVY 4X4 WON'T ENGAGE

1999 Chevrolet S-10

Drive Train Axles Bearings problem
1999 Chevy S-10 6 cyl Four Wheel Drive Automatic 106, 00 miles

Hello, I have a 99 s10 blazer and the 4x4 won't engage. All buttons stay lit like it should be working. I can a noise from underneath the vehicle like it's engaging and a click noise from behind the glove box. I recently had 3 days where the vehicle would not start, it turned over and wanted to start but it didn't. Then on the fourth day it started with a bump of the key as usual. I also noticed that over the summer the AC air blowing from the dash vents would dissapear when I pressed down on the accelerator and come back when released a little and now just since last week the air from the heater doesn't matter where selected wants to come from the dash only. I'm thinking I have some sort of vaccum leak but from where? Maybe the EGR valve was stuck open making it not start? It does idle a little rough but the engine runs very strong any other time.
Avatar
DANNO424
January 9, 2009.



Hi: this sounds like it all could be related. There are vacuum lines that engage the 4wd at the axle. Check to kake sure there is vacuum to them. Also, you may want to check the same thing at the heater control.