I have a 2000 Jeep Cherokee Classic, 6 Cyl. 4.0 193 hp, 4WD, 73000 miles. One of the hydraulic lifters clatters when I first start the car after it has been setting over night. Do I need to change all of the lifters or just the one that is making the noise? Is there any additive that will help this problem? Also after engine warms up the oil pressure seems low to me at idle, 10- 20 lbs. Is this due to bad lifters?
Thank You In advance,