Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 3 of 3 Posts

·
Registered
2004 Trailblazer LS 4.20 L
Joined
·
125 Posts
does it blow blue smoke at start up? how often do you add oil if at all? if you dont need to add much oil between changes and its not coughing out blue in the morning then you just need the gasket, grommets, spark plug tube seals, and yeah spark plugs will get that pep back in your step. mechanic probably pulled a spark plug and the well had some deep oil in it. thats common, burns up plugs too. its from the seals leaking, not blow by.

look at rock auto for cheaper parts. some people will try to tighten the valve cover bolts up but id be careful. use a torque wrench if possible but if they are real loose you can gently snug them. wont help the plugs out much though
 

·
Registered
2004 Trailblazer LS 4.20 L
Joined
·
125 Posts
They looking into that too.

Thanks.

Thanks for the info. Love this vehicle and want it to last as long as possible. I am still learning when it comes to working on them though.
the PCV can cause increased crank case oil pressure, which gets relieved through the spark plug tube seals and valve cover gasket. whichever gives first. either is better than the head gasket. any time you've got missing oil it could be something less than great. pint every three thousand is enough to start investigate for sure. i like to change my 4.2 L6s at three when im running dinosaur oil and getting it done somewhere.

point is you may as well have that PCV changed on while they in there. should have almost no oil usage and minimal leakage afterwards. as long as they are competent or experienced with the atlas motors. sounds like wrench #1 just didn't know what they were looking at.
 

·
Registered
2004 Trailblazer LS 4.20 L
Joined
·
125 Posts
I too have similar seepage, changed PCV hose on driver side (GM #12575660 ) after cleaning with carburetor cleaners, Mechanic could push compressed air from driver side vent, still have high oil consumption.

Last week fixed vacuum leak on break booster.
you can try to look in the spark plug wells and see if there is oil in them or you may see oil on the sides of the block. those things indicate a valve cover gasket mating issue. oil dripping from the drain plug may indicate a stripped pan or plug or leaky oil pan gasket. oil on the filter points to a poor seal on the filter. blue smoke at cold start is a sign of weak rings on the pistons.
 
1 - 3 of 3 Posts
Top