I'm looking at a 1999 cherokee 4.0 4x4 auto with 170k miles for $1500.
The seller says it uses coolant but its not going into the oil or leaking out. Also, at an idle the oil pressure drops to 0 on the gauge and the "check gauges" light comes on but doesn't make any noise. Above idle it builds ~40 psi.

Are these common issues? Is this worth the price for me to fix?

Thanks in advance!

 

That's not common, you'd probably be looking for a new engine soon.

 

here's an easy fix... tell the seller you want to have a mechanic check it out... you can have a mechanic give it a quick once over for around $30.....

then you decide.....

 

What's the uncommon problem, the coolant loss or the oil pressure?

 

Both, shouldn't loose coolant or have no oil pressure. They are more than likely related

 

Exact same thing when I bought mine. Mine was a flood salvage tho. My coolant loss was from my upper waterpump hose. It dumps coolant at a hot idle only so check that out. It's right in front of the block almost dead center check for the puddle after you've been driving

Oil pressure could (hopefully) just be the sending unit. But it would also be bad oil pump, cracked head (but probably not if your oil is clean), bad cam bearings. Hook a mechanical gauge to the sending unit and if the pressure is still low that's a bummer. Run the engine til it blows up on you, that's my plan.

 

It could be as simple as a leaking hose and a bad oil pressure sending unit. Look at it and see. If those are the only two issues on an otherwise clean xj, I would pay 1500 for it.

 

What if it needs a replacement engine? How much would that typically cost?

 

It's 2013 man, not 1973
I wouldn't get of of bed for $30.
Probably $100+

 

no wonder why I can't find good employees anymore... that's the problem, everyone just wants a paycheck in today's generation

i hear ya, but actually it would only take a handful of minutes... sold a car about 5 yrs ago and the girl had a basic once over from a mechanic... cost her $50... even put it on the hydro lift to make it official !!!!

it was a car less then a year old so how hard could it be...

 

This is exactly what I was going to say. You will never find a shop that will inspect it for $30. As Turbo said it will be at a minimum $100 to have it checked out.
You said that the current owner says that it's not leaking coolant and it's not going into the oil and it's using coolant??? It has to be going somewhere! Before thinking of buying it I would do a compression test and do a pressure test on the oil sending unit with a mechanical pressure gauge.

 

who cares anyhow op stated he already owned the jeep but fact is he hasn't even bought it, besides what's $70 between friends.... I brought this up as an option for op, as anyone who's trying to hide something isn't going to be kosher with you taking to mechanic.... first warning sign

I'm not talking a complete 9k point inspection, were talking basic compression and fluid check.... all of 15 minutes??

 

I actually had my shop give mine a look-over after i already bought it.. $35. If your mechanic knows you'll be back they tend to give breaks on stuff like that.

 

I would assume its going into the cylinder and being burned/sent out the exhaust.

Where is the sending unit located?

 

The oil sending unit is just above the oil filter. But you should still do a compression test on all of the cylinders too.