Hello,

Since last week i am the proud owner of an Chevrolet Blazer LT 1998 has run 77500 miles. Runs fine, no problems whatsoever.

After an Oil change the engine runs very rough / stumbles and stalls, ticking sound not varying with revs. Check Engine does not lit.

The next day at startup no ticking only rough idling, does not stall, after a few minutes the engine runs smooth. Oil level and pressure is good. Used oil 5w40, this type of oil was also used by the previous owner.

I don't think that the oil change has anything to do with it, i think this is not a mechanical but an electrical or sensor problem.

Has anyone an idea.

Greetings from Holland

my owners manual and my mechanic says that 5w30 should be used. I have a 1998 blazer as well.
Your owners manual should say the same thing. 5w40 I believe is a thicker oil, that might explain the rough idling. As the engine gets warm the oil thins out and the engine runs smoother-I think. Run that by your mechanic.