[amaurer]

I just checked the oil on my 3B for the first time in about 1500kms, I was down almost 2 quarts!! Funny thing is, I don't know where it went!

-I know my compression is good, (~395-400), I'd be a little surprised if the oil rings were shot given that the rest seems fine, but maybe I'm dumb.

-I don't drip any oil, but there are a number of parts (front main seal or front of oil pan, can't tell which) that keep themselves soaked.

-I don't smoke blue at all. The engine doesn't seem any smellier after sitting for a while.

The question is, could I lose 2 quarts from seal leaks while driving, even without seeing drops in the garage???

Also, when do you check your oil? Hot or cold, idling or running? I find my readings can vary quite a bit depend on when I check.

[UpsideDown]

it takes about 7.5 litres to fill a 3b. You should check it after it has been sitting - engine off - for a few minutes.

It's normal to use a litre or so between oil changes. If you're really looking for missing oil, then check your vacuum reservoir - there is a drain plug on the bj42s that can be used to check for oil.

Hth, john

[canucksafari]

Hard to say. I had the disappearing oil experience a couple times. The same thing with no blue smoke. I changed a couple things. One, I went back to OEM oil filters or Fleetguard becuase they both have the the anti-drainback valve. I have two filters which lie on their sides, so it makes a big difference. I also always allow the engine to run for at least 5-10 minutes and then shut down and wait 5 minutes or fill with fuel and then check. Also, try to make sure you are on dead level ground. With my rig a little slant can make a big difference on the dip stick.

Of course it could be bad news and your front main seal is shot. Hope not. Try keeping a regular eye on it - check a couple times a week or every few hundred kms. Ivf it is the front main seal, don't delay in replacing it. Just like fresh oil and filters, seals are cheap - rebuilds aren't.

[amaurer]

well I went out to see what I could see under there; the front main seal is my area of concern. The front 2" of the pan were moist with oil, but not neccesarily soaked with fresh stuff.

There were a couple drips hanging from the front pan bolts so I tried to snug up the pan bolts. None of them were tight, some were quite loose. In fact I couldn't get any of them to torque to 13ftlbs per the engine manual, the gasket started to squeeze out from the pan and I got nervous before reaching the proper torque and stopped. The gasket that poked out was black and obviously slippery, I think I've got a leak there for sure, but I can't say for sure if its that or the front main seal.

Sooo. Any thoughts? How much fun is replacing the pan gasket? What about the front main? Which sounds like the problem?

[canucksafari]

Bet it is the gasket/gasket maker RV sealant. Not sure which is worse to do on your truck. To be sure, degrease and keep a close eye on it before pulling things apart. You should be able to see where the oil is coming from if you retorquing did not solve the oil weep.

[amaurer]

Is the 3B oil pan gasket cork or rubber? I found aftermarket pan gaskets for $7, or SOR has OEM for more. Does it matter?

[canucksafari]

Originally Posted by amaurer

Is the 3B oil pan gasket cork or rubber? I found aftermarket pan gaskets for $7, or SOR has OEM for more. Does it matter?

So it is not the frfont main seal?

For the pan, I'd use black RV silcon seal gasket maker and forget the factory pan gasket. Just be careful not to put too much on and make sure the mating surfaces are nice and clean (clean with brake cleaner to remove all oil residue). Careful not to put on so much that it can squeeze out to the sides. Follow the directions on the tube. This is an overnight job. Let the RV set-up overnight and then torque to specs the next morning.

[eleblanc]

Post good pictures and you will get a good free inspection!

[Granite Grinder]

I'd use form in place gasket silicone for the pan. The front seal isn't hard to replace, just a bit of a PIA to get to. You should be able to use a seal puller or Ciaran uses a couple of small screwdrivers. Use the old seal to press in the new seal.
GG

[lostmarbles]

Originally Posted by amaurer

......when do you check your oil? Hot or cold, idling or running? .....

Always with the engine off ---- and better still -------- after it has been left sitting overnight too.

I would imagine that checking it "while idling after a cold start" would account for as much as a 2 quart drop in oil level (because that is the amount likely to be sloshing around in the upper reaches of your engine at that time).

Edit -later same day---- Hmmmm. Perhaps I exaggerated a bit here. 2 quarts would be rather a lot... (- But I standby my statement that it will certainly be difficult to get a reading on the dipstick with the engine running.)

I like to check my oil after it has sat overnight because at that time the level mark is the most "distinct" on the dipstick. (Black oil on the dipstick up to a point beyond-which the dipstick looks almost perfectly clean.)

I'm always keen to make life easier for myself

[code 621]

I got a cork one from 4 wheel auto and put a thin coat of the blue gasket materal on both sides. Did this back in January and no visable leeks. Side cover gasket too.The passenger side of my engin was CAKED! Now its almost clean.

[amaurer]

pic, haven't cleaned anything yet.

[PressOn]

I used the same recipe as Code 621's, cork with a thin layer of blue RTV between the block and cork when I pulled my pan. (Thank you mud post whoever it was). I knew a rebuild was in the near future and it made for easy removal and reuse. Any how, that was 10,000 miles ago and it is holding well even after the rebuild.

Jeff

[crushers]

pre85 uses cork gasket, after 85 is just silicone.

looks like front engine seal but not 2 litres worth...
fill back up properly and drive another 1500 km and then check again

[Joe Egolf]

In the am before starting and on a level surface. That pic sure looks like pan gasket leaks to me.

[lostmarbles]

Originally Posted by Joe Egolf

In the am before starting and on a level surface. That pic sure looks like pan gasket leaks to me.

Or the front seal.

I'd fix all leaks (especially ones that look as bad as that one) before considering the possibility that you're burning the oil Drew.

[roscoFJ73]

Looks more like seepage than leakage. If you had lost 2 quarts through there,the oil pn would be covered.
Fixing them wont hurt though

[crushers]

Rosco
my point exactly

[amaurer]

It looks like it the front seal, I found oil on top of the pan lip. I'll add that to the todo list.

However, I agree it'd be amazing if I lost two quarts there, I'm fairly sure I didn't. How would I know if I need new valve guide seals? Could I lose 2 quarts there? Am I right in not suspecting my oil rings based ona good compression test?

[crushers]

if you lost 2 quarts through the valve seals you would be burning blue quite a bit...

[amaurer]

Well, I haven't noticed any smoke, but I do smell something from time to time (its tough to me to choose between diesel exhaust and burning oil). When I use the engine to brake, like when coasting down a hill without pressing the clutch, I smell "something" the most; someone told me that means you need valve seals.

I'm really at a loss to find where all this went, its frustrating.

[crushers]

are you SURE it was topped up properly at the beginning of the test?

[amaurer]

Originally Posted by crushers

are you SURE it was topped up properly at the beginning of the test?

No. I'm checking it daily now trying to establish a baseline. I'll have 200km's by Tuesday of next week, maybe I'll see something.

[Granite Grinder]

Correct me if I'm wrong (happens all the time)
If your oil rings are worn, you'd see blue smoke from the tail pipe.
If your valve guides are worn, you'd see smoke in the form of blow by... might show up from the breather tube or if you opened up the oil filler cap it would be coming from there?
GG

[amaurer]

I don't think so, the valve guide seals the valve stem, which passes through the intake/exhaust channel, not the combustion chamber. Any blowby would have to sneak around the (closed) valve itself, through the intake/exhaust channel and out of the seal... i kinda doubt that.

[crushers]

blow by is the excessive pressure that can be built up in the oil system (not related to oil pressure)... i.e. oil pan, rocker cover area etc
so worn oil rings can let combustion pressure leak past into the oil pan area and thus pressurizing the rocker area and the blow by, since there should be no pressure in this area (other than that created by moving parts.
worn oil rings and worn valve seals and valve guides allow oil into the combustion chamber there is evidence of blue smoke.

make any sense?

[RufusTheDufus]

Originally Posted by amaurer

When I use the engine to brake, like when coasting down a hill without pressing the clutch, I smell "something" the most; someone told me that means you need valve seals.

The 3B in my BJ42 does the same thing. I know I need new rings. My compression numbers are very low so I put a leak down tester on it which confirmed it's the rings.

I go through what I consider to be a lot of oil. 1 quart every 500 to 700 miles depending on altitude and load. Most of that goes right out the breather tube in the form of oil vapor, much of it ends up coating the underside of the vehicle.

My uneducated guess about the smell being stronger on deceleration is the throttle plate. Take your foot off the pedal when the engine is spinning faster than idle and it's going to create vacuum in the intake tract and combustion chambers. If you've got bad rings and/or valve seals the vacuum generated is going to suck oil past them into the combustion chamber.

I really noticed a difference in smell when I took the top off this year. There's a noticible difference in the smell of dino oil and synthetic too.

[RufusTheDufus]

BTW, have you tried to get a friend to follow you to watch your exhaust color? Mine puffs blue only on deceleration. It's not enough blue smoke to see from the driver's seat though.

Do you get blue smoke at startup? That would be the most common indicator of bad valve seals.

[lostmarbles]

My 2c .... As I see it..........

The exhaust valves run far hotter than the intake valves - so wear on their stems and seals occurs faster. Thus, when you have "worn VALVE seals/guides/stems", the symptoms are normally caused by oil from the rocker-cover area (top of engine) dribbling down the exhaust valve stems/guides into the exhaust ports. This is seen as blue smoke -

• On start-up after the vehicle has been left sitting for a while (where the oil has had time to dribble into the exhaust ports and accumulated there), and
• When you first apply power again after "engine-braking down a long gradient" (where again, the oil has dribbled down the exhaust valve guides/stems). - But this time, because oil is still being continuously pumped into the rocker-area, there is usually a greater amount of oil that has accumulated in the exhaust before you hit the accelerator to burn it - So the smoke cloud should be more noticeable in this test/scenario.

Now if you have worn compression rings, this allows combustion gases to escape into the crankcase on each cylinder's ignition/explosion (rather than being contained in the combustion chambers). This abnormal flow of gas, if it becomes high enough, will carry oil droplets with it. And an engine must be "vented" to prevent this "gas leakage" from pressurizing the engine crankcase (and thereby prevent any pressure build-up from blowing out the crankshaft oil seals). Mine has a "breather/blow-by tube" that exits above my front driveshaft. So this tube will cover my front driveshaft with engine-oil if my compression rings are badly worn. Other engines may have the blow-by routed into their air-intake - Here excessive blow-by (and consequent oil-carry-over) will result in blue smoke from the exhaust whenever you apply power (- as that oil passes through the engine and gets burnt).

Now - to have oil-loss caused by "worn oil rings alone" (while your engine still has good compression on all cylinders) - Well - I'm not sure that is likely/possible. --- Is it? (Rare enough to be ignored?)

So - as you have good compression figures Drew - I would think leakage from seals/gaskets is the likely culprit - and that perhaps you are mistaken about the magnitude of your oil-loss.

And I doubt you have a valve guide/seal/stem problems because I would expect you to have noticed the significant smoke that would have generated.



PS. I know I'm repeating what's already been explained by others. But I thought there was a need to throw it all in one post.

[amaurer]

Good advice, and summary Tom.

A lot of my symptoms are contradictory...

-No smoke, at any time. Not even at startup after a long sit. Its warm here in the mornings (low 60's F) so that helps, but I haven't noticed anything blueish.

-Stinkiness when decell'ing.

-Good compression, but I do have blowby. I run a catch can to stop the occasional drip. (brain bender, I know)

I'm watching the oil level daily, I'll try to get a good number.