: After head gasket repair engine knocks



CadyPR
11-05-07, 02:52 PM
This is my first N* and i was really happy up to now. I just finish replacing the head gaskets on my N* 1997. My mechanic misplace the "Knock Sensor that gose to the lower back side of the engine block (Engine blcok to firewall) and still we have not replace it. But anyway we started the engine and it has an engine knock when we rev it up, as soon as the engine RPM's stabilized (maintain the engine at a custant RPM) it goes away. This repair took my mechanic almost 3 weeks to complete, could it be that the rings sticks and make the piston snap against the cylinder walls???? Or it could be because it is missing the sensor?????:banghead:

Scotty7751
11-05-07, 04:06 PM
doesnt the knock sensor adjust timing based on what it hears? so i think it would be the sensor. and piston slat happens with he skirt of the piston so if you have like really short skirts on a piston it will knock bad when its cold cus the skirt hast heated and swollen up. that is what happens with the 6.0 truck motor if you listen the 6.0 it knocks on first startup.

EcSTSatic
11-05-07, 04:06 PM
Could be the sensor. What kind of gas are you using?

urbanski
11-05-07, 04:16 PM
moved.
questions belong in the proper forum for your vehicle.

AJxtcman
11-05-07, 06:18 PM
This is my first N* and i was really happy up to now. I just finish replacing the head gaskets on my N* 1997. My mechanic misplace the "Knock Sensor that gose to the lower back side of the engine block (Engine blcok to firewall) and still we have not replace it. But anyway we started the engine and it has an engine knock when we rev it up, as soon as the engine RPM's stabilized (maintain the engine at a custant RPM) it goes away. This repair took my mechanic almost 3 weeks to complete, could it be that the rings sticks and make the piston snap against the cylinder walls???? Or it could be because it is missing the sensor?????:banghead:

I have seen it many times.
Bad cams!:banghead:
I will post a picture later

CadyPR
11-06-07, 05:12 PM
I think I got it, apparently it was that ignition cable #2 & #4 arcing, apparently this was causing to ignite cylinder #2 when it was coming up to its compression cycle and causing the piston to knock. Today i will go and buy new cables, i will advise tomorrow.

Life is Good!!!!