Bought a ?certified used? 2006 Trailblazer last year. It has an inline 6. Lately, it?s been having trouble starting sometimes, but not every time. When I turn the key, the starter will have no problem cranking and turning the engine. However, once the engine ?catches? it will sometimes get real bogged down with the tach going to 0 and the engine feeling and sounding like it?s going to stall. After a second or two of that hesitation, it will rev back up and run fine. It?s a similar phenomenon to when I?ll turn on the A/C in one of our older cars and the RPM?s will go down and the engine will strain for a second or two.
On the worst occasions, the engine seems to make a brief grinding-type noise. A really awful sound. Any suggestions on what might be going on or where to look before the warranty runs out?
I don’t know what to say about the ‘sometimes grinding noise’.
The Idle Air Control valve may be causing the bad idle fault.
Perhaps a good cleaning of the throttle body will help.