N52 intake camshaft seize

Question

My car overheated and I got the oil symbol while driving. Shortly after my car stalled and I haven't been able to get it to run. I opened up the valve cover and the bolt for the intake camshaft sprocket was was lose and part of it had snapped off. When trying to manually turn the crank only the exhaust camshaft turned. I then tried to turn the intake camshaft with a wrench with no success. What would be the next step it seems like the problem is mechanical so I shouldd start tearing the engine apart in order to find the problem or try pouring wd40 down cylinders and try to turn it by hand agai

Answer 1

If the intake cam is not turning, you've got major mechanical issues. Your N52 engine is an interference engine, meaning the pistons and valves share the same space, only at different times during the cycle. If your intake cam has stopped turning, this means your intake valves have stopped moving. This leads to pistons coming in contact with the intake valves. Usually, this causes at a minimum bent valves and probably worse. The only way to know the full extent of the damage is to take the engine apart and see where the damage lies. You might be able to get away with a new head, but if you can get a used engine with decent mileage on it, this might be a better way to go. Whatever the extent of the damage, trying to turn the engine over by hand is only going to cause more damage, so don't do it.