BillR
Toy Jeep driver!
- Location
- Flagstaff, AZ
My son left this morning in his XJ to head back to San Diego. He made it about 100 miles when some knocking started.:tear: I went and brought it back here.
Here are the symptoms:
1. Oil pressure is good when cold. I just started it and had 40psi at idle. It does go down quite a bit when it warms up. When he called from the highway, he said the pressure was really low.
2. When I started it just now, most of the knocking seems to be while the engine is winding back down after a slight rev of the motor. There's a very short rattle as it's winding up, then a much longer one while the RPMs are decreasing. It sounds just fine at idle, or at least I can't hear anything unusual.
3. When I put my fingers on the valve cover, I can feel the vibration when the knocking happens.
The engine has 138K miles, and had the head welded at about 125K due to a crack from overheating. (before we bought it) They also replaced the WP, radiator and belt at that time.
Fill me in...where do I start looking?
Here are the symptoms:
1. Oil pressure is good when cold. I just started it and had 40psi at idle. It does go down quite a bit when it warms up. When he called from the highway, he said the pressure was really low.
2. When I started it just now, most of the knocking seems to be while the engine is winding back down after a slight rev of the motor. There's a very short rattle as it's winding up, then a much longer one while the RPMs are decreasing. It sounds just fine at idle, or at least I can't hear anything unusual.
3. When I put my fingers on the valve cover, I can feel the vibration when the knocking happens.
The engine has 138K miles, and had the head welded at about 125K due to a crack from overheating. (before we bought it) They also replaced the WP, radiator and belt at that time.
Fill me in...where do I start looking?
