Oil out the tailpipe

After a hard day of wheeling my oil pressure was getting lower and lower. I checked and I was low on oil so I put in a quart. Well, maybe an hour later, same deal. I added more. One tail pipe looked like it had some oil in the very end of it by now, just a little oily residue.

Well, on the way home my idle oil pressure dropped below 10 so I stopped again, checked it, and again it was low. Added more.

When I finally got home I've got oil spewed out the pipe and my idle pressure is down close to 5 (I had to rev the engine at stop lights to keep it up).

I'm I looking at rebuilding my bottom end now? I really don't want to spend the money on an engine rebuild...

 

I just thought of something. There was a VERY long climb on the trail we did, past 30 degrees. Could all my oil have sloshed to the back of my pan? I was watching where I was going and not my pressure then. Maybe I ran dry and damaged my piston rings.

 

Nobody with any input?

Also, I somehow doubt my dipstick is stock. Is there a chance that it reads wrong? Would over filling the system cause a drop in oil pressure and cause it to leak out into a piston?

 

The engine is the original with 83k on it, no rebuild as far as I know. The screen shouldn't be plugged, I did a new gasket on it a few months ago and the pan was squeaky clean (besides copious amounts of oil). Engine is bone stock, never modified. I'll pull the plugs. and see.

The oil is only coming out the side that you fill on. Maybe it's not going down but that seems unlikely. Can I check that by removing the valve cover?

Could I have sprung a leak somewhere on the top end that would leak down into a cylinder? I'm not getting a milkshake on the dipstick so its not an obvious head gasket failure.

Could over filling it cause extreme low oil pressure?

 

It wasn't running poorly. It seemed to be doing ok. There was no abnormal noises or shaking.

Now that I think about it it seems odd that that much oil would come out if just my rings were bad. I would expect it would have just burned and smoked like crazy. There wasn't even any smoke out the tail pipe, just oil.

Hmm... I think I need to open up my top end.

How would I check to see if its going down that exhaust valve guide?

 

I'm starting to think I'm going to need to wait a few months until I can get back to this jeep... I might just deinsure it for the next few months and save it all for a complete rebuild.

 

One way to be sure the oil isnt to full would be to drain and refill with the proper amount- this would also allow you to check the dipstick to make sure it is accurate. You mentioned a long steep hill climb? I know very little about engines but I have a 750 brute force ATV and If my oil is overfilled or even full It will do the same thing on long steep hills. It will lose all power and blow straight oil out of the tailpipe. I changed the plugs and it runs fine. It takes a while to burn the oil out of the tailpipe! If it were me I would make sure all plugs are firing (clamp a timing light on one at a time) If they all run and your oil level is ok...............Run it!

 

It wasn't pushing the oil out until long after I got off that climb, and it's been getting progressively worse.

I spoke with a friend and we decided before we go nuts and rebuild we're going to take off the valve covers and try redoing some seals and things. If that fixes it it'll be a cheap fix. If not, it would have just been part of the rebuild we'd have done anyways.

 

As a tecnical matter - I believe overfilling can indeed cause low oil pressure, if the oil is whipped to foam by the crankshaft.. Maybe that foam could be getting into the PCV system and sucked through the cylinders...

Only a thought.

Pete

 

check you intake valve , If you lose a lifter or push rod and the valve dosen't open it will suck oil pass the rings and push it out the exhrust pipe. Check your spark plugs . the wet one is going to be the bad one

 

false. It most certainly can, it is called aeration, though probably not his problem. Before you pull anything do the standard compression check, leakdown test etc and see what is wrong before you start throwing parts at it.

 

Leak down test? I'm not familiar with that one.

 

You have to be systematic. Start with the easiest tests first: Plugs? (Glenn was on the right track here) Oil fouled? Post your results with pics.

Then do a compression check. List the values. Squirt some oil down the plug holes, turn it over a few times and measure again. List those values.

If the two previous checks are inconclusive, go on to a leakdown test. That pressurizes each cylinder with compressed air, and you check for where the "leakdown" goes.

 

I think I'll dig into this weekend. Is there anyway I can check my oil pressure gauge? It's always possible my gauge is just going bad. Doing a rebuild because a gauge is going would be an expensive mistake.

The funny thing though about it is that its not misfiring or running rough. That makes me think that I'm not getting oil into the cylinders, the amount of oil I'm getting out is pretty large. I'll double check that though by pulling cylinders.

 

I'm pretty sure my dipstick is just some random one the PO had lying around. I'm wondering if it reads low, so a bad gauge and a bit low dipstick made me overfill. That could have made it foam and start getting everywhere inside and even coming out in odd places. I'm just hypothesizing on the cheap stuff to try along with the tests before I do the expensive stuff.

 

Compression test, inspect plugs, chnage oil to a higher weight (ie change from 30w to 40w) for a starting point.