2.8L spewing oil

I have an '86 Cherokee Pioneer with the 2.8L The oil pressure gauge will go past 80 on the dash during highway speeds and then go back down to 40 at idle. It spews oil all over the underside of the truck when going down the highway. I read on here someone said the main seal could not be fixed on these engines... can someone clarify that? I tried to locate the leak, it appeared as though it was coming from where the oil pressure switch and oil filter attach on the driver's side of the engine. It's hard to really tell since oil is freakin everywhere. Also any advice on the crazy oil pressure is appreciated

Another thing related or not- when i turn the steering wheel or turn on the A/C the idle jumps up significantly; so much the truck will lurch forward.

I'm poor, this truck was given to me and I cannot swap the engine so I'm stuck trying to fix it. thanks for your time

First of all, the carb has an idle kicker, where it will sense the extra load of the AC or the power steering pump and kick the idle a bit so it will not stall. This kicker is adjustable so you can decrease the 'kick' a bit .
These little oil pressure gauges are not the most accurate, but my 2.8 L jeep behaves in the same way.
Your leak might be from a bad oil filter, or a leak form the oil pressure gauge sender, or there the adaptor screws to teh block.

Get a can of engine shampoo or brake cleanner and clean off the oil soaked area throroughly.
Have someone start the car while you look at the area. Use a flashlight if you have to. If the leak is that big, it should be easy to find.

As for the main (crankshaft) seals, they are quite easy to fix. Sometimes these seals leaked a bit when new, but the aftermaket seals are quite easy to install and hold up better than the original ones.

thanks for the info. I'll be working on this thing this weekend.

I've been working and learning on this truck for some time. I fixed most leaks with the acception of the main seal. The Haynes manual calls to remove the trans completely. Is there an easier method? Maybe moving it to the side slightly? I know probably not but my workspace is a sidestreet which gets sketchy when cars past. I don't have a garage to work on. Looking over the directions this may be out of my novice mechanical ability.

And also, what is a good rate to have a shop put change it. I've gotten quotes as high as $500!!!

The mid-80's GM motors used RTV sealant instead of gaskets on a lot of mating joints (valve covers, oil pan, thermostat housing, to name afew). Over time, the stuff dries out and you get a leak (or two or three). One area to redo (with a proper gasket) is the valve covers. A leaking valve cover can appear as if you have a bum main seal because the oil will flow down into that area near the engine/tranny junction. I have an '85 S10 with this engine... thought I had a bad main seal also.... turns out the oil was coming from the back end of the valve covers; it would only leak when the engine was running and drip on the ground for a short period of time then stop. Once you think everything is resealed, powerwash the engine to remove all the old gunk, then you'll be able to better see any new or unfixed leaks. The oil filter mount is also another area of known leakage.

The early versions of the 2.8 had a one-piece main seal; major PITA to fix (as in a minor engine rebuild and big bucks). The newer engines had the more normal 2-piece seal; much easier to fix but still an expensive repair. I believe the seal upgrade was a running change in the '86 model year.

Your oil pressure; is this a factory gauge or add-on aftermarket? If it's factory, a new sending unit may be required. If it's aftermarket, it could be the sender or the gauge itself. Usually as an engine ages, the oil pressure goes down all across the operating range. 40-45 psi is typical for non-idle and 14 psi or so is a typical idle reading on a healthy engine.

The idle solenoid, or kicker, is adjustable; it sounds like maybe yours might be a little off. Invest in a good shop manual so you can work on your jeep.

mike