1991 cherokee diesel oil?

i have a 1991 jeep cherokee w/ 4.0 inline 6 gas engine with 225,xxx miles with low oil pressure. iv heard you can use 15-40 diesel oil on higher mileage engines. reason being the diesel oil has a lot of cleaning agents in it that help clean the older engine and the thicker oil will tighten up clearances and give u a little more oil pressure. is this something worth trying or am i going to wreck my engine by using diesel oil?

3 Answers

  • 8 years ago
    Favorite Answer

    yes you are right about it helping with oil presser. but i have neaver heard about the cleaning aspect of diesle oil. i do know diesle oil is designed for a diesel engine. and oil for a gas engine is designed for a gas engine. if you compar the backs of diesel oil and gas oil jugs and look at the code that ses what the oil is one has a CI on diesle oil and the other has a SI gas oil the CI means compression ignition and the SI means spark ignition. you can get 15w-40 ment for a gas engine. i would just put that in with a bottle of stp oil treatment and that should help

    Source(s): mechanic
  • Anonymous
    4 years ago

    It seems only like the main bearings and connecting rod bearings are worn. additionally cam bearings will reason low oil stress. i do no longer know concerning to the jeep, yet, some engines have a stress valve in the back of or close to the oil clear out. this is in case the clear out receives stopped up, the engine can nevertheless get oil. now and lower back the alleviation spring interior the valve receives vulnerable and motives low oil stress. wish this enables. grasp tech forty years.

  • Kenny
    Lv 7
    8 years ago

    Have use it to quiet some lifters. I only used half a quart(worked). You can try 2 quarts replacement and see how it goes.

    Granted it have more mineral/metals but I have think it should be okay. Don't think it will affect the catalytic converter.

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