I have recently purchased a 1990 Grand Am that had problems with the oil lifters. The engine ran but had a tappet sound in the exhaust port side cam area. My stepson and I tore the engine down to the point of oil lifter replacement and started the process of reassembly. Once the engine was assembled it would not start. Is there more than one position for the engine crank when set for the timing mark with the keyway? Is it possible to be 180 deg off causing the engine to lock up?
1990 Grand Am Timing
- Thread starter BruceW1
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The Grand Am I purchased has a LGO 2.3L, High output version installed. It has a standard transmission (neither original equipment). The replacement engine had 15K miles according to the previous owner statement but apparently didn't have the oil changed recently/regularly as seen by scoring of the cam races and housings. This induced wear by plugged lubrication holes in the housing. We replaced both the housing and cams along with several oil lifters from another 90 Grand Am after checking the lifters were correctly sized to the same (only so much money), oil and filter. I now wonder if other areas could be simularly affected. When reassembled the engine would not turn over with a starter. We timed as per the book instruction for alignment of the cams (pinned) to the crank key position with the indexed.
Since then the engine has been taken back down to check that something wasn't assembled incorrectly (stepson learning). This leads back to the original question.
Since then the engine has been taken back down to check that something wasn't assembled incorrectly (stepson learning). This leads back to the original question.
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was number 1 cylinder at tdc with everything lined up? can you turn the engine over with a wrench on the crank bolt and the spark plugs removed?
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Maybe I'm a little slow but I thought that with each turn of the crank all 4 cylinders rotated through one cycle. Is the crankshaft key position when pointing at the index mark directly above on the outer casing indicating cylinder 1 is TDC? I guess that's why I'm asking the question...can there be a position 180 deg out from cylinder 1 at TDC?
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a 4 cycle combustion engine requires 2 full turns of the crank, intake, compression, power, and exhaust, each step is an up or down movement of the piston and rod. Did you try turning the engine with a wrench after removing the plugs? The link below mentions problems with intake valve interference if not installed correctly.
http://www.justanswer.com/pontiac/2o6zl-97-pontaic-grand-gt-motor-quad-2-4-need-know.html
http://www.justanswer.com/pontiac/2o6zl-97-pontaic-grand-gt-motor-quad-2-4-need-know.html
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After reassembly of the engine the first time we manually rotated the engine crank through 4 complete cycles with a wrench to check for valve interference, all appeared well during the test. We don't own a compression tester although that was a recommdation of the mechanic that gave advice. My bad for not completing that step as it would be a double check would be nice but since the previous check had passed I allowed my stepson to continue. The number one cylinder was not checked for position till assembly was complete. It was then he mentioned it was necessary (related by a friend helping at the time). The engine did not complete a startup (using the starter) but appeared to be locked up, I wasn't there to witness this.
At this point I'm unsure if damage was done to the valves but did check the positioning of all before the second assembly. All valve tops appear to be setting at the same height when a straight edge was laid overtop so I've started second assembly.
I'll recheck items noted in your link. The timing chain location Out vrs In was not marked by my stepson so unsure which side should be out. Is there a way to tell?
At this point I'm unsure if damage was done to the valves but did check the positioning of all before the second assembly. All valve tops appear to be setting at the same height when a straight edge was laid overtop so I've started second assembly.
I'll recheck items noted in your link. The timing chain location Out vrs In was not marked by my stepson so unsure which side should be out. Is there a way to tell?