Could a mechanic think the piston is seized when actually it is the MAF cam/crank position sensor?
My 2002 Pontiac Grand Prix GT 3800 as had many problems since Sept 2012. The engine has had the manifold gaskets replaced with the new style ones that don't melt. Now out of no where the engine seized. Just before it happened I lost accleration, Temp when up and a ticking noise like there was no oil. I guess before I call it dead because the mechanic wants to put another engine in (not going there) I would like to know could there be a mistake? Does anyone have experience with this? Thanks.
A maf, cam or crank sensor will not cause an engine to seize up, some internal engine part failed. the 3800 engine as with any engine can give you years of trouble free service or years of headaches. I know of one engine problem the oil pump failed under warranty so they put in a used engine, it had a noise at first then it went away, thought it might have been a piece of carbon, ran fine for 2 months then one morning it started to make a knocking noise, back to the shop, they found that the noise that was there before was the oil pickup tube had been damaged and was cracked so the oil pump was sucking air more than oil and ran the number 3 rod dry, so warranty finally broke down and replaced it with a "crate" motor that car now has over 185000 miles without another engine problem. Just some info for you.
check oil level, if close to ok, try cranking with good battery ,if tight its seized! why ? maybe oil flow restriction, why temp.high? maybe was before seize ! pull plugs, squirt oil in, socket on damper pulley nut,try rotation. if moves can be saved maybe! cure oil restriction. filter,pump pickup as shoe bomber says ,or pump drive ,or gasket material in pump cogs snapping drive off. must pull pan to see ?.
Could be hydrostatic lock. Remove all 6 spark plugs and try cranking it. Could be the intake gaskets failed again and one or more of the cylinders is full of coolant. If this is the case coolant will squirt out the spark plug hole(s) on the effected cylinder(s) while cranking. A blown head gasket can do this too. HTH. -Jim
The 3800 had intake problems they like to eat away between egr circuit and a coolant passage, most likely got coolant in a cylinder and hydro,lock a cylinder..
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