98 cherokee i6 with about 150,000 mi. On it with what sounds to be a light rod knock. (yes ive checked flex plate).

I am getting ready to do my winter oil change, but i have never had this car in freezing temps, so im asking for recommendations.

I usually use 10w30 castrol gtx high mileage synthetic blend. I have been hesitant though because i have heard that these engines do not like synthetics, and dino oil is best. In my opinion oil is oil, but i would definitely say the cherokee is picky with some things.

Should i stick with the synthetic blend or go to castrol dino oil?

And should i stick with 10w30 for the winter months? In philly its getting ready to be 5 degrees but could see temps up to 50 degrees in the same week, so would 5w30 be a good choice or does the 4.0 not like it? Plus i know regular dino oil is thicker at startup

Just keep in mind my engine is older and lets just say the p.o. Wasnt meticulous with maintenance, so im unsure about anything synthetic.

Thanks for reading guys

 

You're fine with the Castrol.

More importantly use a high quality filter like Wix or Napa Gold.

 

What about mopar?

 

I switch to 5w30 in the winter to make it easier to start because it gets well below zero here in Chicago and when I'm in Iowa its even colder. Oil likes to get very thick here.

 

Okay if you change every 4000 miles or so.

 

The Castrol HM is fine, but I'd use 5W30 in the winter. Like cruiser, I prefer Wix/NAPA Gold filters.

 

+1

 

Okay so i think ill stick with the Castrol hm, and switch to a 5w30 weight.

As for the filter, i usually use napa gold (have it on there right now). But i have a purolator pureONE that will fit just sitting aroubf collecting dust. I never had Any issues with them in the past. Any thoughts on using it?

 

I used the Pure One filter here and there when it was on sale, never had any issues with it. If you have it, no reason to not use it.

 

+1, it'll be fine.