Getting lots of oil in intake on new engine

[Jsutton]

Hi All -

I think my first post/question here - I've read many and thanks to all for very valuable information and insight. I have been restoring my mother's (original owner Calif. car) 1981 Fiat 2000 F.I. for several years now - it was "free" to me since my brother got it from mom at 80k miles. His kids drove it from 80k to 110k miles when transmission went, so it needed tranny and some body work and the interior was a bit rough. Since it sat and they did nothing for a few years when stored engine got a bit rusty inside. Now after complete motor rebuild (9.8 CR pistons I seem to recall) & tranny rebuild, also cleaned up interior with new dash and carpets, re-did the suspension with new springs, bushings, tie rods, shocks, etc. and sandblasted and epoxy-painted my original Speedline 13" wheels (a good $12-15k into my "free" Fiat) it just won't start.

I am getting copious amounts of oil coming through the intake and pouring out from the air filter intake (after soaking air filter) and onto the floor, like a full quart after 3-4 starting attempts of 20 seconds each. I took the plugs out and rubber manifold boot off cranked it with a remote starter after cleaning up the mess (a quart of oil goes a LONG way on the floor !!!) I see nothing - dry as a bone, no oil coming up from breather hose or intake plenum. I set the timing with a light to the marks for ~10 deg BTDC on #4 and put it back together and same result - big oil. It almost seems like oil pump volume, wouldn't think it could possibly be this much just from new unseated rings and blow-by since it never fired yet, but I think my no-plugs test negates that theory.

I suppose my next test would be to determine if the oil is actually coming up from the breather tube or is it somehow coming through the intake plenum - I could remove that cover (probably should at this point to clean oil out of it) and check....

Has anybody experienced this before and/or have any recommendations?

Thanks,
Jeff
P.S. - my father-in-law is Italian and was a Fiat dealer here in the metrowest Boston area back in the day, hoping to take him for a ride in it for his 93rd birthday soon!!

[Nut124]

Who rebuilt the engine?

Yes, I think you need to figure whether the oil is coming from the breather. Trace the hose from the oil separator, disconnect it from where it goes at the intake and try starting. If the oil is coming from the breather at idle, then I'd say there is a bigger problem than ring seating.

I am not aware of any other path for oil to get to the intake, other than the breather hose.

[Jsutton]

Hi -
Thanks for the quick response. I had local automotive machine shop do the engine and short block assembly and I put the head on and assembled the rest of the motor - I have done a few other model cars before and mostly do motorcycles for hobby restorations. I also do sandblasting, powder coating and zinc plating, have a lathe, Bridgeport, Solidworks and 3D printer for those "impossible to find" parts. Let me know if you need something "challenging" done.

One thought I had was perhaps oil is over-filled. It's all original dipstick, etc. so not likely unless it's not seated properly and reading high. I could drain and fill by known volume rather than trust dipstick. I'll certainly look into the breather as next step as well as clean up the intake plenum and let you all know what I find.

- Jeff

[Nut124]

Even if the sump was over filled, it should not push oil out like that. Oil fill after rebuild should be around 5L, perhaps a bit more, but not 6.

Who specd and bought the rings? Was the block bored oversize?

[Jsutton]

I got the pistons & rings as a set from Autoricambi, about 0.020" oversize if I recall, no issues on the size from the machinist and I was not trying to overbore anything substantial for power increase, just for bore cleanup.

[18Fiatsandcounting]

This is bizarre, and it's almost like the engine is operating in reverse and pumping oil out the intake, which isn't possible unless there is something seriously wrong. If oil were getting into the intake, I would expect it to be sucked into the cylinders and coat your spark plugs, but that's not what you're seeing.

Nut is right; the only real path for oil into the intake is the breather hose, but I can't imagine a scenario with the quantities of oil you're seeing after only cranking the engine.

At this point, I'm puzzled, and my only suggestion is to drain the oil and make sure it's not somehow overfilled.

-Bryan

[Nut124]

Spraying oil leak from the galley plug on the right front side by the water pump?

Sprays onto the airbox when you crank?

[Jsutton]

So I tested it and the oil is definitely coming only from the breather - I put the disconnected end of the breather in a ziplock bag to catch the oil and it did. Nothing from intake plenum or anywhere else externally on the engine, not from galley plugs (all replaced by machine shop with rebuild). The oil was travelling down the intake boot from the breather hose port and into the air filter before.

I didn't remove the intake plenum cover and don't think I want to at this point. I removed the breather and associated hoses to inspect and see what I could see - not much, pretty basic and simple. It does have the rubber baffle washer, which only seems to fit one way. I did another test with the breather removed where I put a paper towel wad into the big breather socket in the block and another one into the smaller adjacent pipe that connects to the breather with the short rubber elbow and gave it a crank - didn't see much, maybe a little oil on the larger breather socket but nothing like what I was seeing before. Cranked a couple more times and still not much oil to speak of - I would have expected one of these wads to be soaked or even blow out, but nor the case. Maybe I "fixed" it?!? LOL...put it back together and we'll see.

The motor has yet to actually fire up, I've only seen a couple sputters or backfires in intake, which concerns me - may have some fuel issues with the injection system (doesn't smell like gas, which I would expect to smell if I had an ignition, timing or compression issue). It was a complete running car before but sat a few years.
I don't seem to have a flame trap in the breather hose, will have to get one. I'm thinking my next step is to put a little fuel into each spark plug hole and try to fire it up, confirm I have decent ignition (I'm getting decent spark and timed with light, so I would expect it to run).

[Nut124]

???

At this point, I would do a cranking compression test and see what if anything it reveals.

It seems that something is pressurizing the crank case. Totally bad rings could do it. Compression test results would help figure path forward.

Edit: I would also suspect high oil level. Even if rings were shot, pressure in the crank case should evacuate thru the breather w/o pushing out oil. Presure could push oil out only if the oil level is high enough to block the passage of gases from the crank case to the breather. I would think this would require the oil level to be high by several inches. I had an old block sitting around but got rid of it this spring. Now I wish I could examine it.

Any chance your engine is pouring gas into the crank case increasing the level?

Check the underside of the breather "cap". Make sure there is no crud there. Crank case pressure is supposed to be able to exit thru the breather hose while any oil in it gets trapped and drains back to the pan.

[18Fiatsandcounting]

At this point, I'm thinking the same thing as Nut, that pressure in the crankcase is building up and pushing oil out the breather tube. The question is why? In addition to making absolutely sure the engine isn't overfilled with oil, I'd verify that the breather "cap" is not blocked with crap (as Nut suggested).

One problem with this explanation is that I would have thought the pressure would have pushed the dipstick out, but maybe it's enough pressure to carry oil out the breather but not enough pressure to blow out the dipstick?

-Bryan

[Spider951]

Just a very wild guess here - you mentioned the engine sat for a while and got rusty. Is there any possibility that an oil passage is clogged (with rust, gunk, critter "homestead" )?? I don't know enough about engines to hazard a guess whether or not that could result in oil being forced out somewhere it doesn't normally go.

Sgt. Schultz Engine Rebuilders

[Jsutton]

I drained the oil today and got about 3.75 quarts, which is right on spot for the capacity of 4.25 quarts per manual and what had leaked, so the oil is not overfilled. Curiously I did notice/hear an odd bubbling or gurgling noise coming from inside the block while the oil drained - not sure if this is typical for this motor as I have never changed the oil in a Fiat before but sounds perhaps like oil is somewhere it is not supposed to be? Looking at the parts diagram for the breather assembly there is a pipe that goes from the bottom of the breather into the oil pan, function is supposedly for cyclone separator to drain back into oil pan? Seems like this may be the path the oil is coming from in wrong direction.

I did a compression test, got 220, 180, 190, 225 PSI in cylinders #1,2,3,4 respectively, nothing terribly out of the ordinary here IMO for a new motor that hasn't been broken in yet - correct me if I'm wrong here, but no unreasonably low numbers that would point to major blow-by. This block was professionally disassembled and cleaned, hot tank I believe and reassembled (short block) so I doubt there are any blocked passages.

I tried putting about 0.5 mL gas in each cylinder with a long eyedropper and replacing the spark plugs, etc. and firing it up - got a brief "stumble" after several revs and a backfire in the intake, then nothing, maybe another backfire after cranking a while longer and another oil puddle in my intake (same result as before).

I'm at a loss at this point as to what to do or why this is happening, suppose I could start tearing things down to see what is up, maybe drop oil pan to get a look at the breather pipe, etc. and see if something is off there, maybe chase down that gurgling noise when draining the oil.

[18Fiatsandcounting]

The gurgling noise is odd, and I don't recall ever hearing that on a spider engine. It's almost like an oil passageway is blocked somewhere, and oil is pooling somewhere and not draining smoothly down to the oil pan without some "burping" along the way. But then the question is why is it being forced up the breather tube?

I'm still mystified, and at this point, I would be thinking about removing the oil pan and see if you can figure out what going on from the bottom. Check that the bent drain tube from the breather well down to the sump isn't clogged.

There are wild and crazy possibilities like you have a crack in the block between an oil galley and the breather setup, but you still shouldn't see oil being drawn up the breather tube without something pushing it along. Like significant blowby which you shouldn't have with your compression numbers and on a new engine.

Maybe disconnect the breather tube (using the Ziploc bag trick) and focus on getting the engine started?

-Bryan

[Jsutton]

Thanks - I think I'm going to try and isolate the two different hoses for the breather and run them into a coffee can or ziplock while blocking the other one with a rubber stopper to see what happens, last time I did this without isolating them it seemed to be only the large breather side giving up oil and not the barb fitting. I'll also connect a pressure gauge and see what kind of pressure is actually being generated in the crankcase/breather and if that is a common/universal pressure or isolated to one passage or another. If I'm going to drop the oil pan I'll replace it with a new one with baffles to prevent air from entering when cornering, etc. - wish I had done that/known about them before putting it together. I'm not going to race or autocross but occasionally like to "drive it like I stole it". I WILL get this figured out and running, no matter what.

[18Fiatsandcounting]

I don't know why this didn't occur to me before, but if the engine is not running (firing), you shouldn't be developing any pressure in the crankcase. Sure, the crankshaft and cams spin around and the pistons go up and down, but there shouldn't be any blowby. Or any pressure at all, really.

It's like an oil pressure line is somehow connecting to the breather setup, but I can't think of any (reasonable) way that would happen.

Sorry I can't offer more. Weird.

-Bryan