Oil wieght 1998 wrangler 4 cylinder 175,000 miles what is the oil wieght I should use thanks for the help

Click of the following direct, Free Link. It has several Serpentine Diagrams, including the one for your 1998 Jeep Wrangler 4.0L In-Line 6-Cylinders based upon your Engine Options (AC/No AC, Power Steering/No Power Steering, etc.).
The Link Page ALSO has the 2.5L In-Line 4-Cylinder Serpentine Belt Diagrams with their various engine options.
Included are the with AC / without AC Routing.

Let me know if this helped, or if you have additional information or questions. Feel Free to contact me at FixYa.com!
http://www.2carpros.com/car_repair_information/year/1998/make/jeep/model/wrangler/1998_jeep_wrangler_drive_belt_routing_diagram.htm

HELP WITH WHAT IT IS CHEAP ENOUGH TO DO YOUR OWN SERVICE CLEAN THE PLUGS WITH WIRE BRUSH DRAIN OIL AND FILTER IT USING RAGS CLEAN OIL FILTER WITH WHITE SPIRIT AND PETROL

Well, it depends on what the average temperature is going to be in the area the vehicle will be used. There's probably no place in the Continental US you could not get by with 10W40.

Oil weight and viscosity and there temp. ranges:

Hope this helps,
Mike...

quite possibly it may be taking a little while to build fuel pressure. next time try cycling the key on and off 3 or 4 times with out cranking the vehicle to allow the pump to build pressure the try to star it up if it starts right up then your problem is it's just taking time to build pressure

Actually oil pumps in the JEEP 4.0 are notorious for going out or wearing at 1500000 miles as you will find in most blogs and topics. And the 4.0 is a very solid motor capable of 300,000-400,000 miles if taken care of,unless driven hard I wouldnt say it would be worn out!

You need to find out if you have spark there, if injector is working and if the cylinder itself has good compression. Then, you can work backwards to find out why whatever is "missing" isn't there.

check fuel for pressur and quantati to fuel rail posable fuel pump or regulator

Wire on oil sending unit may have fallen off or sensor itself may have gone bad. Check both. If engine has no tapping noises, likely it's not a pressure problem.

If your going to chg. head gasget, as long as you got the head off you would be smart to have a valve job done too. That could be why you lost compression in the 2 cyls. burnt valves will cause loss of compression. But take note if you elect to have a valve job done you also run the risk of it to start useing oil because of the increase in compression on the oil rings with that many miles it can happen.

there is an oil seal between the transfer case and trasnmission housing, if your bearings have gotten hot in the transfer case, this could have caused the oil to heat up and damage the mechanical seal