Piston broke
New Member
Hi Guys,
A few months ago I had a problem with the engine in my Jeep. It looked as though a valve seat dropped out and proceeded to chew up the head and piston.
I didnt have time to do the strip down myself so gave it to a mechanic to do. The bottom end was fitted with new bearings etc, new timing chain and sprockets and a new piston and con rod assembly fitted. On the top end, for cost reasons I purchased a complete used head assembly from a vehicle dismantler. I checked the head out for cracks, flatness etc and found it was in top condition. In fact the head looked pretty new. I have finally rebuilt the engine but now I have this problem! It wont start properly. By this I mean that before just one turn of the key and the motor would burst into life. Much like a dog when someone says Walkies! But now it just wont fire up. However, if i turn the key to ignition on position and then off quickly for a couple of times it fires up straight away when I turn the key to start. The check engine warning light stays on. A friend used a scanner on the car and told me the fault was due to low fuel pressure. I check the pressure myself and found I had about 55psi so I dont think that was the issue. I had another scan done and was told the problem was due to the relationship between crank and camshaft. I checked the positioning of the sprocket with cylinder 1 at TDC and found this to be correct. I also changed the cam position sensor but I still have the same problem. The only thing I can think of is that there is some difference between the Camshaft and associated parts between the original and new heads.
Anybody out there with any ideas????
A few months ago I had a problem with the engine in my Jeep. It looked as though a valve seat dropped out and proceeded to chew up the head and piston.
I didnt have time to do the strip down myself so gave it to a mechanic to do. The bottom end was fitted with new bearings etc, new timing chain and sprockets and a new piston and con rod assembly fitted. On the top end, for cost reasons I purchased a complete used head assembly from a vehicle dismantler. I checked the head out for cracks, flatness etc and found it was in top condition. In fact the head looked pretty new. I have finally rebuilt the engine but now I have this problem! It wont start properly. By this I mean that before just one turn of the key and the motor would burst into life. Much like a dog when someone says Walkies! But now it just wont fire up. However, if i turn the key to ignition on position and then off quickly for a couple of times it fires up straight away when I turn the key to start. The check engine warning light stays on. A friend used a scanner on the car and told me the fault was due to low fuel pressure. I check the pressure myself and found I had about 55psi so I dont think that was the issue. I had another scan done and was told the problem was due to the relationship between crank and camshaft. I checked the positioning of the sprocket with cylinder 1 at TDC and found this to be correct. I also changed the cam position sensor but I still have the same problem. The only thing I can think of is that there is some difference between the Camshaft and associated parts between the original and new heads.
Anybody out there with any ideas????