Which oil? New mojito rider

First of all let me tell you that it is a myth that you can not go back and forth between conventional oil and synthetic or in your case synthetic blend. They all mix very well together but why on earth would you not use a full synthetic in every thing? It will keep your motor so much cleaner, and last way longer, new or 150.000 miles used, does not matter. They refine the synthetic oils way way longer to get the impurities out. Other big thing [ OILTEMPERATURE AND WEAR COLD START UPS ] Exceeds and blows conventional out of the water. plus a real full synthetic you can run a lot longer just spin a new good grade filter on or change it. Me my self Ill run Walmart full synthetic in my grand prix and ROYAL PURPLE in my 2013 mustang. I think there all full synthetics are good compared to the old dirty sludge and if all the new manufactures are recommending it now its good. Do you have any motor rebuilders or trucking builders close to you? Just go look at the oil pans to compare the too . I guarantee you will be sold that day and never run conventional again.... PERIOD.

it indicates worn hydraulic followers , worn main and big end bearings , worn oil pump
The sludge build up is from not changing the oil on a regular basis
every 10,000klms or 5,000miles
short runs and not allowing the engine to get hot enough to boil off the water vapor from the combustion process
When it comes to oils , it is a personal preference and when you understand that oils ( synthetic or otherwise) carry additives to hold water in suspension, add tensile strength to the oil so that it can keep the moving bits separated and not touching, maintain viscosity and lots of other purposes, then you will realize that over a period of time all of those additives get neutralized and the oil is useless(sludge )
there is not an oil on the market that will last 12 months in an engine even though new car manufacturers claim it to be so
so changing the oil regularly means that sae 20w-40 mineral oil is just as good as the very expensive synthetic oils and cost a lot less
I find that using diesel oil ( shell rotella 20w-40 as an example) will keep an engine clean because it has a higher detergent additive to keep diesel engine clean of carbon

valves could be bent?? is the engine smokey

its mostly personal preferance.. your trailblazer doesnt call for synthetic so if you dont want to spend the extra cash i would just get a decent brand 5w30 or 10w30

Just go get it changed by a professional, it takes quite a bit so I wouldn't risk doing it yourself and put your car in potential danger, overfilling and under-filling is dangerous for any car. On a side note, try using synthetic oil, I tell everyone this because, although a little more pricey, synthetic will make your car last much, much longer than normal oil. It takes 10W30 oil and, as I stated before, try synthetic out, it goes for an extra 2-3 thousand miles longer and it makes your engine happy.

hope it helps.

sounds like stuck needle valve if it's carbureted,letting the gas run into the engine filling it up,has to go somewhere if its full,you need to drain it out,don't try to start it,with all that gas in the oil it will not get proper lubrication resulting in engine damage.Shut off the fuel valve or it will continue to run into the engine.Hope this helps

I wouldn't sweat it unless clutch is slipping. . Never heard of semi synthetic .

Buy a new ignition switch, it will come with keys.

For the best results use a full synthetic oil - not a synthetic blend. When you change oil filters add an Engine Sentry to the filter.,,