1998 Jeep Grand Cherokee Laredo. 108k miles. Very clean, every button works from the back to the front. Only rust I saw was on the exhaust and drive shaft.
About a year ago my wife and I were on the way home, we live in the middle of no where, and we saw a lady in a jeep with steam coming out of the hood. We pulled over and ended up towing her to the closest town which happened to be where we lived. She left us her name and number and then called and got someone to pick her up. Fast forward a year I told my wife to offer the lady $100 bucks for her jeep or to come get it. She meets my wife at the tag agency, signs of the title for a nice 100 dollar bill. So here I am, jeep has been sitting a year but I replaced the leaking upper radiator hose, put in a new thermostat, flush the radiator the coolant and refilled it, oil change, topped off all fluids, added some fuel cleaner crap and a few gallons of fresh fuel (gauge was just above E when it was parked), put in a battery I had laying around and it fired right up.
Replaced upper rad hose and t-stat. Radiator actual looks like it is in good shape not sure about water pump but do not see any seeping. Also with the t-stat Ive seen a lot of people mentioning drilling holes in it, some at 12 and some at 12 and 6. I have no experience with this and didnt bother with the one I put in.
Idles rough, have to feather the gas a bit to keep it from stalling out. Pulled the idle air control and cleaned it up. Idles, a little rough still but it idles without assistance.
Next, air bubbles in overflow. I attempted to burp the engine, seems almost like exhaust leak from a bad head gasket maybe?
Valve cover leaks.
Trans pan leaks. Going to replace trans filter as well when pulling pan.
Rear main seal or oil pan leak. When replacing the gasket should I bother with oil pump? Oil pressure is nice and steady and not showing any signs of the pump being bad.
Head gasket..not even sure if it is bad but I know this can be hard to find and since I have to replace the valve cover anyways should I just do this? And get the head checked for cracks while it is off.
Now that the little history I have is done here is my main question. Anything else I should be replacing with the head off? Should I just replace the Idle air controls, MAPS, and the other sensor on the throttle assembly? What am I missing? Also what parts should I be replacing this stuff with? I know Mopar and Fel-Pro are what people always say but sometimes they are 5x as expensive as others.
In my opinion, don't pull the head until you're sure the gasket is blown. There is a test kit you put on the radiator cap that will tell you if you have combustion gases in the coolant. How are the spark plugs and wires? Distributor cap and rotor? As far as sensors are concerned, Mopar is best for anything that communicates with the computer. Yes, they cost more, but they also last a lot longer and provide the signals the computer is programmed to expect. At 108K miles that engine has just reached maturity! As the saying goes, "Don't fix what ain't broke! It will eventually." The only thing to replace while the head is off is the lifters, but yours should not need that yet. Replace the valve cover gasket and thoroughly clean the engine top and bottom. Oil from a valve cover runs down and makes it look like a rear main seal leak, so watch it after you clean everything to see if it's actually leaking before you pull the pan. Mopar makes a premium sandwich gasket for the trans that doesn't need sealer and can be used several times. It's made with a steel section between 2 neoprene sections. I've already used mine 4 times. That trans (42re) uses nothing but ATF+4 and nothing else. Make sure any aftermarket fluid states on the bottle that it meets ATF+4 specs. I think your owners manual says ATF+3, but ATF+4 supersedes it. A drain-and-fill will take up to 6 qts depending on how long it drains with the pan off. The pan holds 4 qts. I happen to like Valvoline products because I've been using them since 1965 and at one point worked for Ashland oil.
I got the rear main seal, oil pan gasket, and the trans filter and gasket done yesterday. One thing I have noticed the last two days is some oil rings in the coolant reserve tank. Took it off clean it real well with some simple green, reinstalled it, refilled it, and then ran the jeep for a bit to check the bottom for leaks. Still leaking from the oil filter adapter though, mine has the damn torque bit one which I need to buy. After I got everything buttoned back up on the bottom I it a bit around town and still seeing small oil ring residue in the coolant tank. Replacing disp. cap and rotor, wires, and plugs today. Also going to be pulling off the throttle body assembly either today or tomorrow and clean it all up. The jeep isn't wanting to shift past third gear and it is throwing a code for the throttle sensor or something. Hoping cleaning it all up and replacing the gasket on the throttle body will fix that issue.
Bottom of my oil pan was antifreeze. Looked nice and clean when I drained it. Was dumping the rest and right at the very bottom was a very unhappy sight.
