hi i am new to the jeep world there for new tho this site. i always wanted a cherokee and finaly got me one and i love it. i got everything working on it but i have a question for you guys. i ts a 99 cherokee sport with 165,000 miles. the oil pressure gauge reads fine when i first start it up. but avter a couple miles< when i slow down or stop the gauge goes just a little under 40 psi. than when i give it gas it goes back up past 40 to a normal pressure. does anyone know what this could be or if i have to worry about anything? thank you for your help

i have that same thing too. Is it knocking at all? When i bought mine a couple months ago the pressure would go real low (below ten at points) and would start to knock below 1000 rpm. Right now mines in the shop getting a new engine because of all that. Try taking off your radiator cap (when its cool!) and see if theres any gunk built up on the underside of the cap. If there is take it down to your mechanic and get it taken car of.
Then again i could be completely wrong

umm if you listen real close, and i meen close you can here a slight knock but nothin i havnt herd in brand new cars. i think its just a noise due to having so many miles. it hasnt been abused and had regular oil changes from what i can tell. its probably due for another one by now wich im goina do in a bit. it just started going that low about a weel ago. when i got it it would only drop to about 40 psi. now its going a little under. i will check the rad cap rite now and see if theres any gunk or anything like that

It is normal for the oil pressure to drop slightly after the oil is warmed up.

Thats what ive been told by locals. I just wanted a second opinion

You can increase the weight of the oil. From 5w30 to 10w30 or even 40. At 100k+ its not going to hurt anything.

Ron