I’ve replaced mass airflow , fuel pump, cap rotor, fuel filter, catalytic converter, muffler, and i’m still having problems with engine. No power, feels like it’s a clogged cat but that has been eliminated. Idles fine, give it some throttle and it falls on its face and you can hear the valves rattling. Any suggestions and or help would be greatly appreciated.
How many miles on the 4.3 liter V6? Is the check engine light on? What error codes is it showing? Why did you replace the parts you did?
hello. approx 200k . No check engine light. Had several codes and i replaced parts and no longer have those codes. P0420, P0101, P0300, P0756. Any idea what else could be the problem???
Yeah, the engine is worn out. With valve clatter on startup, the cam might have lost a lobe or 2. If you hear “valves rattling” when you accelerate, it may not be valves, it might be pistons slapping around in the bore. It might be a worn timing chain slapping inside the timing cover. If it jumped a tooth, that might explain the power issue.
Since all the codes are gone, I’d go “old school” with the diagnosis tools and do a dry and wet compression test. I’d also pull the valve covers and watch the valve action when the engine cranks to see if they all move enough to open the valves. I suspect the engine is worn out.
That’s what i was afraid of. I’ll do compression tests. But unfortunately i think you are correct in your assessment. Thank you for the help. Hoping to fix this or replace engine with minimal costs.
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I remembered changing my fuel pump 3 times in my old Astro. I cut an access hole through the floor pan just above the fuel pump to remove it. Seemed like it was a chronic problem with these vans.I agree with Mustangman that your engine is probably worn out.