QuestionQUESTION: okay i have a 2001 chevy astro 2 wheel drive 4.3 liter v-6 and i was having overheating problems/it nover boiled over but i have had to shut the engine off- but i flushed and refilled the system and it still seemed very hot and to be idling fast and sluggish and then it starteddeveloping a knocking on startup and after warming up it would stop knocking/i tried burping the system and after warmup it stopped and it ran great instant takeoff and hardly any gas and it was running quiet like a new car and then over night it started good the next day and then started developing a knocking on startup and would eventually go away until i would stop the engine and park while shopping and on startup again with the knocking any ideas you could give me would greatly help, its a good engine great power and pick up and would like to save it before its beyond saving
ANSWER: HI HOMER,IF THE KNOCKING IS FROM THE LOWER END OF THE ENGINE MORE THEN LIKELY IT IS A BAD ROD BEARING.THIS WILL GET WORSE,MOTOR TIME. IF IT IS UPPER END TICKING SOUND THIS COULD BE A WEAK OR FAULTY VALVE LIFTER THAT WHEN IT WARMS UP THE TICK GOES AWAY. THESE 2 NOISES WILL SOUND DIFFERENT CLICKING FOR LIFTER RAPPING FOR ROD BEARING. THE OVERHEATING BOTHERS ME AS WELL.LIKE MAYBE INTERNAL COOLANT LEAK,WHICH WOULD HARM THE ROD BEARINGS.BEARINGS DO NOT LIKE ENGINE COOLANT.WAS THE COOLANT EVER LOW WITH NO EXTERNAL LEAKS ?? GET BACK TO ME IF YOU NEED MORE INFO OR CAN GIVE ME MORE INFO..WHEN YOU LEAVE THIS SITE COULD YOU PLEASE RATE THIS ANSWER.THIS WILL HELP ME,,, THANKS TOM..
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QUESTION: it definately sounds like its coming from the upper portion, when you listen under the hood it sounds like its coming from the a/c compressor so i removed the engine cover in the cabin and its definately coming from the under the rocker cover , right side or right on the drivers side where the pcv valve is, id appreciate it also if you could give me some tips on checking the lifters or valve lash whichever you recommend on doing to find the supect lifter
AnswerHI HOMER, SO YOU SAY THIS IS A TICKING SOUND,NOT A RAP RAP SOUND. THIS IS GOOD. OK IF YOU ARE SURE IT IS UNDER THAT ONE VALVE COVER,TAKE IT OFF AND SEE IF ANY OF THE ROCKER ARM ARE VERY LOOSE. CK BY HAND. THERE MAYBE A SPLIT ROCKER ARM OR A ROCKER BALL PROBLEM..I DO NOT HAVE MY WORK SPECS HERE ON THE VALVE LASH [ADJUSTMENT] BUT AM PRETTY SURE YOU JUST SNUG THE ROCKER ARM NUTS DOWN TILL THEY NO LONGER TURN,CALLED POSI STOP..WHAT I WOULD DO IS START THIS AND LET IT WARM, UP BEFORE REMOVING THE VALVE COVER. THEN TURN IT OFF REMOVE THE COVER AND CK TO MAKE SURE THAT ALL THE ROCKER ARM NUTS ARE TIGHT. IF YOU CAN TIGHTEN FURTHER THEN YOU WILL NEED TO ADJUST THEM AS FOLLOWS..LOOSEN THE NUT ONE ROCKER AT A TIME, WHEN THE CLICKING GETS LOUDER STOP,NOW TIGHTEN TILL THE CLICK IS GONE AND THEN TIGHTEN 3/4 TURN FROM THIS POINT,AND TIGHTEN SLOWLY TO NOT STALL THE ENGINE. THIS IS HOW YOU DO IT IF THEY ARE ADJSUTABLE LIFTERS,I DONT BELIEVE THEY ARE LIKE THAT HOWEVER. I THINK YOU JUST SNUG THEM TILL THEY STOP.. SO LETS SAY YOU HAVE ADJUSTED THEM OR FIND THE ONE THAT IS CLICKING.REMOVE THE ROCKER ARM AND CK IT FOR ANY PROBLEMS,REMOVE THE PUSH ROD AS WELL,MAKE SURE IT IS NOT BENT. IF ALL LOOKS OK, THEN CHANCES ARE THE LIFTER IS COLLAPSING,,[NOT HOLDING OIL]THIS IS WHERE THE CLICKING STARTS FROM AND GOES UP INTO THE ROCKER ARM.. SO IF THIS IS THE PROBLEM YOU WILL NEED TO REMOVE THE INTAKE MANIFOLD TO REPLACE THEM. ONE MORE THING,ONCE YOU HAVE THE VALVE COVER OFF, WHEN IT IS RUNNING MAKE SURE THAT ALL THE ROCKER ARMS ARE MOVING UP AND DOWN ABOUT THE SAME LIFT OR RATE. THIS WILL CK FOR A POSSIBLE BAD CAMSHAFT,THIS WILL ALSO CAUSE A TICKING SOUND..ALSO WHEN THE TRUCK IS RUNNING IT WILL BE MESSY, THE ROCKER ARMS WILL SHOOT OIL ALL OVER,SO DO NOT REV IT UP.. I THINK I GAVE YOU ENOUGH HOME WORK TO KEEP YOU BUSY FOR A WHILE. GET BACK TO ME ON THIS WHEN YOU FIND OUT WHATS UP. TOM.
