ncwheeler
NAXJA Forum User
- Location
- Garner, NC
I have a '98 4.0l with 128k miles, its been pretty well taken care of and had regular oil changes. Starting this summer I had put 10w30 in it for some reason, prior to that I had always run 10w40. A few weeks after the oil change the pressure started to drop to 20psi at idle (which is about 500-600 for me). After I had driven for about 20 minutes but as soon as I got on the gas it would go up to about 50psi and drop down to 40psi at about 45mph (1500rpm). I figured this was just normal and figured Id just put the 10w40 in it the next time I changed my oil. I changed the oil about a month ago and ever since it has gotten worse. Its stays around 40psi until I have been driving for about 15-20 minutes. Then starts to drop to 20 at idle, still not a problem. However, then it drops down even lower to right at 13psi. I know that some of you say this is fine, but it has never done it before. What do yall think the problem is?