QuestionQUESTION: I am working on a 01 Alero with a 2.4 engine. It was going down the road lost power and died. It had a bad head gasket and warped head. I had the head surfaced and put on new gasket. Before i took the timimg chain off I took out #1 plug and turned over until compression. The dowel holes in the cam sprokets were about 12 oclock, opposite of what book says it supposed to be. When I put it together, it still wont run. Loosened cam housings rolled crank 180. Compression still when dowel hole at 12 o clock. Got fuel coming out of injectors, got spark at plugs, changed both cam and crank sensors but will not run. I am stumped. Do you have any ideas?
ANSWER: HI RICH,OH YES THE QUAD 4 SAGA,EVERYTIME WE REPLACE A WATERPUMP OR DO A VALVE JOB ON ONE OF THESE BABIES WE[[ ALWAYS REPLACE ALL THE TENSIONERS,GUIDES AND CHAIN]].[[VERY COMMON PROBLEM]] .THE FACT THAT YOU HAVE FUEL AND IGNITION WE KNOW THAT IT IS NOT A SENSOR PROBLEM.. I WOULD BE REMOVING THE FRONT COVER AND REPLACE THE PARTS AS I SAID ABOVE. WE HAVE FOUND THAT WHEN CRANKING THE ENG OVER THE TENSIONER LOOSES ITS ABILITY OF KEEPING THE CHAIN TIGHT CAUSING CHAIN TO HAVE EXCESSIVE AMOUNTS OF PLAY IN IT..ALSO YOU MAY FIND THAT THE GUIDES ARE WORN REAL BAD AS WELL,WHICH COMPOUNDS THIS PROBLEM..CALL YOUR GM STORE AND I BET YOU WILL FIND THEY HAVE ALL OF THESE PARTS IN STOCK..IF YOU DO THIS JUST MAKE SURE THAT ALL THE MARKS ARE LIGNED UP PER SPEC. YOU CAN GET THIS ON LINE...IAM SURE YOU KNOW THAT LAST PART,,,AS YOU SOUND LIKE YOU KNOW WHAT IS GOING ON HERE. I HOPE THIS HELPS YOU AND GOOD LUCK..
---------- FOLLOW-UP ----------
QUESTION: Thanks for your response you first question. I do appreciate it. Are the cam sprockets supposed to be lined up with the dowel holes on a compression stroke or are the dowel holes supposed to be at a different point of timing? Do you think I have the crank 180 out or something else not aligned? The guides have a little wear but doesn't look excessive. The tentioner also seems fairly strong, but as you said maybe when cranking i could be getting some slap.
AnswerHI RICH, CERTAIN YEARS USED DIFFERENT TIMING MARK VARIATIONS...I WOULD STRONGLY SUGGEST LOOKING THIS UP ON LINE OR IN A GM MANUAL..I AM PRETTY SURE THIS ENGINE IS OUT OF TIME..KEEP IN MIND,I DO NOT KNOW HOW MANY MILES ARE ON THIS ENG,BUT IF OVER 100K WE ALWAYS INSTALL NEW CHAIN,GUIDES AND TENSIONERS. JUST TO BE SAFE ,WE GOT BURNED ONCE, NOT TWICE... HOWEVER IF YOU LOOK AT EVERY COMPONET AND ALL LOOKS GOOD,JUST SET UP THE CHANIN LIKE THE MANUAL SAYS TO..NOW FOR THE BAD NEWS, I THINK THIS ENGINE IS A INTERFERENCE ENGINE..THIS MEANS THAT IT IS POSSIBLE THAT IF THE CHAIN IS NOT SET UP CORRECT THERE MAYBE PISTON TO VALVE DAMAGE,[LIKE BENT VALVES] I KNOW YOU DONT WANT TO HEAR THAT BUT IT IS POSSIBLE..YOU COULD DO A CYLINDER LEAK DOWN TEST TO MAKE SURE THE VALVES ARE OK...OR JUST LOOK THIS UP IN THE MANUAL AND ALIGN THIS CHAIN TO SPECS AND HOPE FOR THE BEST. I HOPE THIS HELPS YOU...
