Handful of Dumb Questions from a new owner

I'm going ot start with 5 and then add .5 and then .5 again in the same day, I'll let you guys know tomorrow night which one reads correctly, thanks for the scan too timgr!

 

Here's a pic of my Chiltons. Doesen't mention anything about US measure vs. Imperial. I think I have this figured out. IRRC, Chiltons is a British outfit. Land Rovers are British. This is obviously a plot to have us consistently run our engines underfilled, thereby causing early Jeep engine death. They do this in the vain hope of being someday able to claim that Land Rovers last longer. A truly insideous plot. I would expect nothing less from the people who use positive ground on their vehicles...

 

In regards to a new dip stick, if you go to the auto parts store they're going to hand you this adjustable thing that I'm not sure you would want. Best place is to get one from a jeep grave yard or even a place like www.jwjeep.com. Congrats on your new/old Jeep!!!

 

I'm no mechanical engineer so my opinion is not worth much, but I'd venture to guess that it doesn't really matter whether you put in 5 or 6 quarts. I'm sure plenty of identical 258's have been driven for thousands of miles with some guys using 5 and others 6 and it has made absolutely no difference. Just my $0.02 worth.

 

I'm starting to agree with you too, I think it partly depends on how big the filter is and how much it holds on it's own since people seem to be using differnt filter sizes as well. I'm just going to replace mine with the same type as the one that's on there (PH25 by Fram) since it's the company i like to use anyway and it seems to fit.

 

:iagree:


I think that you can use 5 or 6 quarts and the dipstick will still read within it's allowable range. I put another .5 quart in last night and checked the stick, it still read fine.

 

One question I have now about whether putting 5 or 6 quarts will make a difference. Assuming both amounts are fine to run in the rig with out overfilling. What would be better the extra oil, or less oil?

 

I'd guess more oil is better, until the level gets high enough so that it starts getting whipped up by the crank. Too much splash will lead to excessive oil consumption. More oil will mean that the average temperature of the oil should be lower, and any contaminants (oil, gas, carbon) will be diluted by more oil.

 

Would this change the oil pressure any? And what is the average running oil pressure? I have seen my gauge at different times showing a range from 20 to 40 psi.

 

No, I don't think so. Oil pressure will go to zero if the level gets low enough, but more oil won't matter.

Oil pressure will vary with engine temperature (oil thins out when its hot) and engine speed. Maximum pressure is controled by a releif valve in the oil pump, but minimum is due to engine speed.

 

To second what Tim said, as far as oil getting into the engine to lubricate, there are really only two measurements that you care about. (with the caveats that Tim made about contaminants and temp)
1) Too low and the pick up tube for the oil pump goes dry, no oil, = seize-o-rama
2) Too high (way high) and the crank shaft starts to hit the surface of the oil in the sump, whipping it up. This creates foam, lessens surface tension and begins to defeat the pumps ability to suck and deliver oil - see #1

That is why its bad to overfill (extreme) your engine oil and why there are hash-marks on the dip-stick - the sweet range

 

okay, i changed it this morning and it took the whole 6qt before it read full, 5.5 was still in the fill area. Maybe it's the difference in dipsticks, mine does seem short for such a deep engine, but i'm no mechanic. Everything seems fine, did all the generic oil change time stuff to it and all the fittings held grease and all the other levels were good, so i doubt there are any leaks. Here's to the next 3000 miles or 6 months which ever comes first!

 

Well now you've got me wondering. Could I have the wrong dip stick, or a changed oil pan?
On my jeep, 5qts comes to the full mark. For the heck of it, I added 1/2 qt, sure enough, it reads overfull.
So I pulled the stick took some pics and measurements.
1st pic: measures about 1 3/8" to the full mark
2nd pic: measures about 12 1/4" from the stop washer to bottom of stick.

Anybody have those measurements from a known correct dipstick? I'm wondering if the PO stuck something else in there. I know he dragged the shift knob all the way back from NZ, got it off an old wrecked Land Rover he found at the bottom of a canyon when he was wheeling there. Who knows? I wouldn't put it past him to have grabbed the rover dipstick also...called the knob his "Trophy".

The other possibility could be the oil pan in pic 3. I've never seen one with the welded on skid plate, but it looks factory. I guess the question could be which factory? Does it look stock to you guys?

In the end, I don't think it matters much if its just a different dipstick. I'll just dump 6 quarts in it, remark it, and call it good. If there's a chance the pan is an oddball, I'll be more hesitant to do that, because if its shallower, dumping six quarts in it could increase chances of crank frothing. So I guess I'm hoping somebody has seen a pan like this before. If you need a depth measurement, I can go out and crawl under the thing, but I'm hoping to avoid that...its about 147° out there.

 

Dont forget to factor in the oil in the filter as part of the total

What matters is the oil pressure staying up, not exactly, how much is in the pan.

 

I took a few pictuers of mine, I couldn't put them in the attachment thing, so I hosted them on my personal webserver, it's nice to be a network engineer sometimes!

http://static.hibachipenguins.com/IMGP2545.jpg
http://static.hibachipenguins.com/IMGP2546.jpg

 

badllama, thanks, it looks like I've got the correct dipstick. Now I'm concerned about my oil pan even more. It's probably gonna take some jeepin genius to figure this out. After taking a closer look at the filter I got from NAPA, it looks like it'll hold a quart. So now I'm thinking I've got the dreaded goofy oilpan. Its either that, or I've got a one of a kind 258...

 

is your 258 a dual barrel carb or single? I don't know if they changed other parts based on this but mine is the single. I'll try to get under it and take a picture of the pan later tomorrow

*edit*
I won't need to be taking any pictures, my oil pan matches yours EXACTLY to a T, no questions there.

 

Wow after reading the last page here I wonder iffin I put too much oil in my jeep. but I still dont see how this could make the noise.

 

Every Jeep 258 pan that I've seen looks like that, with the skid plate.

 

:iagree:

I just read on an AMC car site the other day that the oil pans on 258's used in AMC cars was shallower (for ground clearance reasons) than those used on Jeep engines, and were therefore only 5qt. capacity. If you have a dipstick &/or pan from a car engine on a Jeep engine or vice versa, it would get a bit confusing.