(Warning: this is a really retarded story that speaks to my ignorance and learn-it-the-hard-way nature. Please bear in mind my novice understanding of auto mechanics...)

I have a 1997 Jeep Cherokee XJ Country straight 6 4.0L with a little over 189,000 miles on it. I've been using synthetic oil for the past few years religiously. It's been in pretty good running condition with no major problems recently.

Anyway, the scenario:

I decided not long ago to start changing my oil myself. But taking off the filter is a chore that ended up with me breaking the oil pressure sending unit. I finished the oil change and drove home. The next day I decided to get a new sensor unit from an auto parts store...

Now for the stupid part:

I unscrewed the part of the sensor that was still attached to the engine, started it up, waited a minute, then drove a couple miles before it dawned on me what I'd done. I pulled over, screwed the broken piece back into the engine to prevent more oil from spewing out (if there was any left). I got a few more miles when a clicking/pinging started with increasing intensity from the engine (the lifters/bearings, I assume). The engine didn't smoke, the check engine light never came on, and there was no significant change in performance. I got to the auto parts store and refilled the oil (dipstick said it was dry) and replaced the oil pressure sending unit. No more pinging/clicking from the engine. No spikes or drops in gauges. No warning lights. No significant decrease in performance (I think the get-up ability may be lagging now but it could be my wary imagination). No smoke. Nothing crazy. Basically, aside from what looks like a few drops of oil when I park the Jeep, I can't detect anything wrong.

BUT, I know that driving 8-9 miles without oil is usually (logically) catastrophic. This was yesterday and nothing has come of it that I can tell aside from the small oil leaks. I bought some more oil and added about half a quart and the level is well in the safe zone if not over. Still, I love this Jeep and want to keep it alive for as long as possible. It's been a real warhorse that has sustained many bumps and bruises and idiocies (had it for 10 years this January).

I have no idea how to proceed in regards to repairs as I don't have much money and couldn't afford a rebuilt engine if it was in the 1,000's without a loan or something. But, as it stands, the thing more or less runs fine. I'm baffled. Any and all advice is welcome. Thanks for taking the time to read.

 

check to make sure the oil isn't dripping off of something where it was squirting out...there is no reason it should be leaking after this...

it's hard to kill a 4.0, if it's not knocking or making funny sounds, i wouldnt be to worried about it, just keep an eye on the oil pressure...

 

You're right about its survivability. I've had to have a good amount of work done on it over the years but, in return, it HAS survived some pretty gnarly abuses, mostly to the exterior, but still. The oil pressure seems to hover around 40 on the gauge. If it starts to dip, at what point should I be concerned? More than one notch on the gauge?

Thank you for the reply, DougyFresh.

 

sounds like your engine is fine. all hail the mighty 4.0!!!

 

Is it uncommon for 4.0's to handle stuff like this? I read one article about a woman who drove 17 miles with no oil, but that seemed either crazy or a miracle to me. I honestly figured driving 8 to 9 miles with practically no oil would kill the thing. I would hate to really damage it at just 189,000 miles; I've read these things last into the 300k range.

 

how much oil did you have to add to it at the parts store?

You will probably be fine thou

 

A full 6 quarts, which is what threw up a red flag for me (but again, I'm inexperienced enough to not realize right away that unscrewing the oil sending unit would spray the oil out). But as soon as I added the oil the pinging pretty much stopped (it's been doing it a little off and on for the past few years, but NOTHING like what happened yesterday). I added some more today just to put my dip stick thoroughly in the safe range. My typical daily driving doesn't take me more than 5-15 miles though.

 

you'll be fine.

i once drove one with power steering fluid in it for oil because it blew out the rear main, and the parts store didn't have enough oil to pour in it for the trip home. straight up power steering fluid.

these things can take it.

 

Did you use Teflon tape on the new sensor when you installed it. Just a thought about your new leak!

 

Just a thought because I've been there with other cars. Driving low on oil can damage front and rear crankshaft seals if they dry out. Usually it's the rear so I would watch for leaks at the back of the pan.

 

I didn't use Teflon tape and I'll be sure to keep an eye on the rear crankshaft seals if things don't improve. Thank you again for the advice, everyone, and if anything else comes to mind or anything else I should watch out for, please let me know.

Thank you again,
J

 

I know this thread is very old but I have to chime in and say that this exact thing happened to me today. I did exactly what you did in breaking off the OPSU sensor, unscrewing the plug part, and starting the Jeep (mines a 98 XJ w 121k). I too few like a complete dummy in not realizing that the sensor is plugged right into the block (also a novice at fiddling around with vehicles). Only difference is I did not drive it, just sat with it at idle for 3-4 mins in the driveway before I caught my mistake. I think I lost about 5.5 quarts. Comforting to hear that someone else has driven it on no oil with little damage to the 4.0.

 

I once broke off the little tube for a mechanical oil pressure gauge on my Volare. Pumped most of the oil out on the ground before I figured out why I was smelling hot oil. At least in my case I was working on it and found the problem before it got empty, but yeah 2+ quarts on the ground in under two minutes through that tiny little line. I'm surprised I didn't hear it shooting out.

 

You'll be fine.