so yesterday i drove my jeep and when i started it up it ran a little rough, on start up it was at 1200 rpm give or take and then went down to a 1000 and stayed. whats with this ?? i checked the oil and its low and time for an oil change, i haven't changed the oil sense i bought it in june so i don't know what oil he was using so can i just put a synthetic in it ? and with that what weight of oil and what kind is the best ? thanks
1991 YJ 2.5l 4 Cylinder, 4.5 Inch Lift, 31's, SYE, SOA Rear, CV Drive Shafts, 5 Speed AX-5 with NP-231 Transfer Case, 4.88 Gears.
Even if you put in synthetic and the previous owner used regular oil, there should only be a little residual amount left over. You could always buy the cheapest stuff, run it for a few hundred miles, and then change it again with your preferred type. Get a useless Fram oil filter to put in for your "cleansing" and then get yourself a good K&N filter when you put in the good oil.
I've had my car AND my motorcycle do that and, surprisingly enough, they both stopped doing it when I stopped using gas from AM/PM gas stations. I use 76 stations now and both run like a charm. Go figure. Bad gas messed them both up. All of my motorcycle riding buddies have had similar experiences at AM/PM gas stations. They'll now use 76 or Chevron and occasionally 7-11. You might also run some Sea Foam through. Get a can at the auto store and pour it in with a refill and it'll clean your system up a bit. Good stuff!!!
Sunny Southern Taxifornia Denizen