HELLO,I HAVE A 96 S10 4 WHEEL DRIVE BLAZER WITH THE 4.3 VORTEC ENGINE.I TOOK IT TO THE SHOP TO HAVE IT SCANNED.THE BLAZER RUNS GREAT GOING DOWN THE HIGHWAY,BUT SHAKES PRETTY BAD WHEN SITTING AND IDLING.IT ALSO HAS A FUEL SMELL.I NOTICED THE GAS MILEAGE ISNT WHERE IT SHOULD BE ALSO.I JUST BOUGHT THIS 2 MONTHS AGO OFF A GUY I WORK WITH.HE WAS TRADING IT IN SO I GAVE HIM 500.00 FOR IT.IT HAS A TOTALLY REBUILT TRANNY THAT HE SPENT 2600.00 PLUS SOME OTHER THINGS THE SHOP DID TO IT.THE SPIDER INJECTOR WAS CHANGED WITHIN THE LAST YEAR ALSO.THE MECHANIC IN THE SHOP CHECKED THE PLUGS AND SAID THEY DIDNT LOOK TOO BAD,BUT CHANGED THEM ANYWAY.HE SAYS THE 2 FRONT CYLINDERS ON THE PASSENGER SIDE ARE SHOWING LOW COMPRESSION,ALSO THAT HE BLEW AIR INTO THE ONE CYLINDER AND AIR WAS COMING OUT THE OTHER CYLINDER.I WAS WANTING TO SEE IF ANY ONE KNOWS IF I NEED A NEW ENGINE OR MAYBE THE HEAD PULLED AND CYLINDERS CLEANED OUT????THIS IS TOO NICE OF A VEHICLE TO SCRAP,SO PLEASE SOME INFO OR IDEAS.THANKS,CARSON

 

Gas smell might me the computer is running it rich which might be due to failing sensors. Did it come up with any codes when the mechanic ran it? As far as the shaking and rough idle how rough is the idle like rpm wise and the shaking is it only when in certain gears or does it do it in all gears including say neutral?

 

Well... If two adjacent cylinders show low compression and air flowing into one, flows out the other, it sounds like a head gasket problem. Probably blown out between the two cylinders... Really need more information though to know if it is truely a head gasket failure. Typically, when a head gasket goes, you get coolant into the cylinders, but it all depends on where the failure occurred... If it is at the closest point between cylinder bores, then it may not. You really should pull the head and have a look.