Mechanic...?

[B192734]

So here's a little story, and a good reason to chnge your own oil...

So there I was. At the mechanic's. Check engine light was on. Bad O2 sensor. 3 times in a row. Faulty parts. It was fun. Hanging out with the boys in the shop. Then it got old. Finally we found a good one and everything was good. The light went off. The Jeep started running well again. Everything was golden in my life. I was at the top of my game.

Then I was driving last night, and happened to look down at the guages. I look at them normally, but mainly the temp and speed-Oh!-meter. I took a quick glance at the oil pressure guage and it was good. Then I happened to look again for some reason about 2 minutes later, and it was spiked. Normally it runs about 40-50 depending on the speed. Here it was at 80! I let off immediately, and it came down to about 78. I coasted it in to where I was heading and let it sit for a while. Happened again on the way home. I started to panic a little, not wanting a blown head or engine in general. So this morning before I was leaving for work (in my wife's car...) I popped the hood and checked the oil. Looks like there's at least 1 extra quart in there. Possibly a little more than that. So today I'm heading home in the pouring rain (and mixed snow) and am going to lay out there in the elements and drain the case. Hopefully that solves the problem and there hasn't been any permanent damage.

Moral of the story:

Change your own oil, or at least double check other people's work. Sounds like common sense, but do we always do it? I know I don't, but will from now on. But who puts 7-8 quarts in a 6 quart engine?

 

[B192734]

So turns out that after I took oil out of the engine to get to a more reasonable level, the pressure guage still shows 80 psi.

Any ideas?

 

[B192734]

Sorry about the third post in a row. So I got off of the phone with the stealership, and We think it's the sending unit (again!). Good fun. I love it! Although this time I think that I'll put it on myself and save the $80 or so...

 

[jeepless20]

check the sending unit for the guage. just a starting point. if you dont know ware it is, it should be right by the filter. at least it was on my 95 XJ I6, dont think thay changed much from then till them. somthing could be stuck maybie. wrong filter? i realy have no idea, just trying to through some ideas at ya. might help a little. hope you get er fixed by morning. supposed to snow again

you posted wile i was typing, how dare you hehe.

 

[mud4feet]

I would suspect the sending unit.........mudwoman's went out ('94 YJ) and spewed oil like you wouldn't believe (busted diaphram) after exhibiting similar symptoms. Can't remember what it cost, but it wasn't anywhere near $80 (I'm thinking in the neighborhood of $20) and was a really easy fix.............trust me, I'm mechanically challenged. Good luck with it!

 

[Saurian]

If you had a quart of extra oil in there, it's gotta release the pressure somewhere, and I would expect the most delicate part for that would be the oil pressure sensor...

I've heard all kinds of horror stories, from leaving the old filter gasket on, snapping off the dipstick tube, all the way up to forgetting the drainplug. When the oil change place told me that I needed a new PCV valve, I got out and politely showed them the CCV system, and have been doing my own ever since.

On a side note, has anyone noticed that the price of motor oil has gone up over the last couple years with the price of gas? It sure did around here...

 

[B192734]

Definitely. Who would think that you'd have to pay so much for a little bottle of goo.

 

[wm69]

I quit going after the monkeys stripped out my drain plug on my Accord. I've always done the Jeeps myself but the Honda is a little harder to get under. I noticed a puddle under the oil pan and saw that they had stripped my drain plug. I go a drain plug with an O ring that fixed the problem and only required 19 ft pnds to tighten it up. I changed the oil a couple of times myself and then was on the way out of town and realized I was due for an oil change so I stopped in, told the guy "do NOT overtighten the drain plug. It only takes 19 ft pnds" He twisted it till it spun freely. I bought a fumoto valve and used blue loctite on it. No leaks and no problems since, but I went ahead and got a set of jackstands and started doing it myslef.

 

[Laph]

I had my dipstick broken off by the guys at walmart, they paid to have it fixed which I did it my self and gave them the bill of 140 buck, 40 bucks and hour plus parts/beer. Thought I was fair, was no reason it should have happened in the first place.

 

[Sparky-Watts]

Definitely check the oil sending unit. Mine went bad on the YJ about a year ago, and it would peg while idling and drop to zero while driving. Then for the next mile, it would be the opposite. Cost me less than $20 at Advanced Auto Parts, and they had 20 in stock (unlike the other guys, Pep Boys and Auto Zone who never have any Jeep parts in stock).

As far as changing oil, I've never had anyone change my oil in my vehicles. I'm not about to put my engine in the hands of some high school dropout. Always done it myself. My dad taught me how to do it when I was 8 years old, as well as the benefits of frequent oil changes. When I was in college (the second time) I worked at Iffy Lube for 2 weeks. It was a daily occurence to have one of the "mechanics" leave either a drain plug out or forget to put a filter on, resulting in a blown engine for the customer. I could maybe understand once or twice a year, but every stinkin' day this happened at least once, sometimes more than once! And I've heard from other people that it isn't just the one I worked at, pretty much all of them have a bad track record.

 

[Laph]

... I'm not about to put my engine in the hands of some high school dropout...

I do every time I work on my jeep, but yea I know what you mean.

 

[wm69]

As far as changing oil, I've never had anyone change my oil in my vehicles. I'm not about to put my engine in the hands of some high school dropout. Always done it myself. My dad taught me how to do it when I was 8 years old, as well as the benefits of frequent oil changes. When I was in college (the second time) I worked at Iffy Lube for 2 weeks. It was a daily occurence to have one of the "mechanics" leave either a drain plug out or forget to put a filter on, resulting in a blown engine for the customer. I could maybe understand once or twice a year, but every stinkin' day this happened at least once, sometimes more than once! And I've heard from other people that it isn't just the one I worked at, pretty much all of them have a bad track record.

yeah, I've always done my own on everything except the accord; it was too dang low to the ground for me to get under without jacking it up, and instead of buying jackstands I thought "it's SO easy. NOBODY could screw up an oil change"

Learned my lesson.

 

[josh]

An extra quart of oil hurts nothing and does not increase oil pressure. Keep in mind if you check the oil after the vehicle has set all night as much oil as can possibly drain back into the pan has done so. This will show over full.
Most people prefer to have enough oil in the engine that the pan remains full while there is oil circulating in the engine.
That is why you start an engine,let it run a minute or so, shut it off and recheck the level.
While this is not much of an issue in jeeps there are some engines (2.7 chrysler) that canstarve for oil around turns if the level is even a pint low.

 

[Sparky-Watts]

yeah, I've always done my own on everything except the accord; it was too dang low to the ground for me to get under without jacking it up, and instead of buying jackstands I thought "it's SO easy. NOBODY could screw up an oil change"

Learned my lesson.

I hear ya! I used to drive my Civic up with two wheels on the curb and lay in the gutter to get under it to change the oil. Only problem with jacking some vehicles up is that it tilts the oil pan enough so that not all of the oil drains out. That was the case with the Civic, it would leave about 3/4 of a quart in the pan if I jacked it up enough to get under it. By driving it up on the curb with the passenger side tires on the curb, it stayed level and all the oil would come out.

 

[B192734]

I've always been taught that the amount of oil that you should put in is what the dipstick says after sitting for a couple of minutes after driving till normal temp. That if youput more in that you are running the risk of a blown head gasket or worse. I've always been paranoid of anything to do with my oil. That's part of the issue...

So how full would you have to go before it starts to become a problem?

 

[josh]

I've always been taught that the amount of oil that you should put in is what the dipstick says after sitting for a couple of minutes after driving till normal temp. That if youput more in that you are running the risk of a blown head gasket or worse. I've always been paranoid of anything to do with my oil. That's part of the issue...

So how full would you have to go before it starts to become a problem?

Well there is no general rule as to how much over causes a problem. See every engine and pan design is different. There are a rew reasons that get kind of complicated but Ill try for the quick and dirty answer.
The first problem you have with overfull oil is a loss of power due to the crank running through to much oil. It is for this reason race engines use windage trays and crank scrapers to keep oil off of the crank at high RPM's.

In a street car or say a jeep 4.0 this would probably not be noticeable. If it became full enough that the crank was "whipping" the oil you would probably get a little foam and excess oil through the breather.

These symptoms would worsen the more overfull the engine was.

Untill you get it ful enough that the cylinders start to fill from the bottom up.
I have seen this first hand on a toyota 4cyl that was filled way overfull.
This causes loss of power and a go go gadget smokescreen. Again the severity depends on how far overfull it is.

The most severe is enough oil to cause a hydraulic lock. Liquids cannot be compressed. So when the cylinders become very full the piston cannot compress the oil and the engine will not turn.

This could theoretically bend rods and break rings but honestly the only time I ever saw this happen it merely fouled the plugs and causes said smokescreen after engine was drained ,properly filled and restarted.

Problems can occur in an oval track car when all the oil gets flung to one side of the pan and the engine starves. If this kind of thing interests you research some of the different ways the circle track guys have remedied this problem other than a dry sump. Ypu will see strange oil pans and baffles and oil levels all over the spectrum.