1990 Chevy Blazer crankcase pressure

HIGHWAYDAVE

MEMBER
1990 CHEVROLET BLAZER

Engine Mechanical problem
1990 Chevy Blazer 6 cyl Four Wheel Drive Automatic

I have 90 s 10 blazer 4 wheel drive been missing and not running well after couple months of replacing almost everything I found vacuum leak I fixed vacuum leak now it runs beautifull untill it getts hot then it blows smoke from leftexhaust it seems like the crankcase is building too much pressure I replaced pvc valve nothing took hose off throttle body no nothing could it be plugged inside throttlebody when I put it in gear under load when its hot I now get a pinging from engine sounds like from underneath at back end of motor but only when under load thx very much for your insight

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

If you get no vacuum at the PCV, there is a carbon clog at the source. Use throttle body cleaner and a piece of coathanger to clear it. Also check the air control out...
ELECTRONIC AIR CONTROL (EAC) SOLENOID 1. Turn ignition on, engine off. Disconnect EAC solenoid connector. Connect test light between solenoid connector terminals. See Fig. 10 . If test light comes on, check for grounded wire from solenoid to ECM. If wire is not grounded, replace ECM. If test light did not turn on, go to next step. 2. Ground ALDL diagnostic connector. If test light comes on, check for faulty EAC solenoid connector. If connector is okay, replace EAC valve. If test light did not turn on, connect test light between harness terminal "A" to ground. See Fig. 10 . If test light still did not turn on, check for open in fuse or wire to ignition. 3. If test light came on, check for open in wire from solenoid to ECM. If wire is okay, check EAC solenoid resistance. If resistance is less than 20 ohms, replace EAC solenoid and perform ECM quad-driver check. If EAC solenoid resistance is greater than 20 ohms, replace ECM only. Fig. 10: Electronic Air Control (EAC) Circuit Courtesy of GENERAL MOTORS CORP. Page 1 of 1 SYSTEM/COMPONENT TESTS -1990 Chevrolet S10 Blazer 9/14/2008