Oil in the air cleaner assembly...

[tercel4wdrules]

I just discovered that oil is blowing onto the top cover of the air cleaner. I hadn't noticed this before and I just replaced the PCV valve about 50 miles ago. I also checked the spark plugs and they are not fouled. The side electrode has some light tan deposits and the center electrode has none. All spark plugs are properly gapped. I got angry because I smacked my face with the spark plug wrench because the person who installed the second plug previously overtightened it, so I had to exert brute force at an awkward angle to loosen the plug, accompanied with a "snap" sound when it loosened.

Now, the question is what could be causing oil to enter the air cleaner assembly, specifically on the top left portion near the HIC valve? There are still some problems with black smoke on startup. If it's not one problem, it's another...

[MootsMan]

I don't like being the bearer of bad news, but it's probably not a good thing you're getting oil in the air cleaner. It happened to me with the '85 ..... due to oil blowing by the rings in the engine as best as I could determine. I had so much coming through at one point that it was running out of the air intake next to the radiator.

It could be caused by other things, maybe something plugged up in the engine, but most likely means that you'll need to rebuild the engine at some point.

[keith]

It it the underside of the top cover or the outside of the air cleaner. If its inside, you have excessive blowby. Normally the pcv valve sucks all vapors from the crankcase and replacement air is provided by the hose that goes from the underside of the air cleaner to the valve cover. This provides filtered air for the engine so it doesn't contaminate the oil. With excessive blowby, the crankcase builds up more pressure than the pcv valve can remove so the oil vapors are blown into the air cleaner.

Look at the bright side, you want to be a mechanic, you get to rebuild your first engine. I hope you have an advisor to help you, you can always come here for advice and we'll do our best to help.

[Typrus]

Mine did it for a while after my new PCV. Ruined 3 air cleaners. I'm kind of anal about my clean filters. I replace them when pro mechanics say they're half done. Lol. Every oil filter change or more frequently usually. Hey, at $6 a piece, why not?

ANYWAY....
I could never figure out exactly what it was associated with. Maybe blowby, maybe carb issues, maybe PCV issues... Who knows. All I know is it seemed to go away about the time I did my first oil change with Schaeffer's Supreme 7000 mixed 50/50 with Mobil1 Premium Full Synthetic. The Moly in the Schaeffer's might have helped. I don't know honestly.

Its possible that with how little you drive the Terc, you might have semi-stuck rings. I doubt its a severe blowby issue if the plugs or even just one of the 4 isn't getting fouled. Blowby doesn't just go one direction.

[tercel4wdrules]

The air filter element has a gasoline smell to it. I noticed there was oil present on the underside of the top cover after I saw a bit of oil on the top rubber part of the air filter. It looks fresh, but I'll wipe it off and see if it continues to blow oil. It could be that the oil is waaay too old, in fact I want to think it's that. I know it probably had done this before because when I first got this car there was some faint brown residue on the carb's throat. Now that I remember, the black smoke has been there I think since I got the car, so it really is nothing new. One thing that really makes me a little uncomfortable is that it has darn good power, but yet it has all of these issues.

Another thing I noticed (yeah, I know...) was I heard it crank unevenly when I was waiting for it to be inspected. Normally, I know how it's supposed to crank, but I don't know if other people have noticed this with their cars. I could just have lost my marbles... who knows?

So, my plan of action is replace the oil (probably with 20W-50 instead of 10W-40) and air filter first. Then see if it still does the same thing. The only way I would know if the engine has stuck rings is a compression test. I'll just have to save my pennies and buy a compression gauge.

For those who don't know, the engine has about 35k miles on the rebuilt engine, which was rebuilt 6 years ago. Actually, it was rebuilt twice. Once it was a full teardown, then 8 months later it states it overheated and the engine was partially rebuilt with a valve job and new bearings and crankshaft + full gasket/seal set. Honestly, I don't think it's worth to rebuild this engine again should it need to be in the future.

Air filters are $6 a piece? Wow... it's really been that long since I've purchased one. Typrus, your car did the same thing too? But your car's engine has decent compression. Might be something screwy that goes on inside. The last time I removed the oil cap with the engine running (several months ago) it was throwing some oil out. Could this be an indicator of blow-by?

Sure, I want to be a backyard mechanic to keep my little car running, but I want to become a mechanical engineer...

Thanks to all for the advice.

[takza]

The hole in the bottom of the air cleaner is where the PCV valve gets it's air to circulate into the intake. The PCV system in this car doesn't really pull a lot of air thru. I see a little oil around that opening with an engine that still gets 5K per quart. Might check for a blocked PCV hose though?

[Typrus]

Yeah, I register good compression on all 4. I dunno why it does it.
Every engine will blow a little oil vapor back out with the cap off. The degree to which it does it is more important than whether it just flat does it or not.

Being a Mechanical Engineer does not mean you can't be mechanically inclined. Just ask me. I ought to be starting towards my BSME within the year, money willing.

If you are going to swap oil out, run something through with the oil before you change it. SeaFoam, Marvel Mystery, BG44k... You decide. Just something to get some of the residue from just sitting around out. Might help free the rings if that is the problem.

[keith]

First of all, never use 10w40, it cokes at a much lower temperature than other oils. Multi-weight oils contain base oil which is a single weight oil, usually the lower number and a viscosity improver (VI). The VI keeps the oil from thinning out as much at higher temperatures. The VI unfortunately lowers the temperature that oil breaks down at. 10w40 breaks down at too low of a temperature. If you use it, you have to change it frequently. 10w30 is much better and I'd recommend that you use it instead of 20w50.

Using a cleaning product is a good idea. I've used 5 minute motor flush on occasion, just don't use it for more than 10 minutes, then drain the oil. You could sub one quart of transmission fluid for a quart of oil in the next oil change. I haven't used Seafoam yet, but a lot of people like it so I'd say give it a try if you want. If the oil gets black real fast after the change, change it again. Despite many people saying that oil color doesn't matter, it does. There are other factors too, but color is a factor as well.

Save some money by using a Walmart Supertech filter and 10w30 oil. The filters are a real bargain and the oil meets API standards. This would put the cost of an oil change at around $10 DIY.

Learning how a car works would probably help you in your career as a Mechanical Engineer. You will have a place to store facts you learn in school. When an instructor is trying to explain a concept, you will be able to visualize it. It will even help you with the math.

[Typrus]

Or if you get into Formula SAE... Hehehehehe... Most of CSU's ME students have never changed a tire, let alone bled brakes, messed with engine timing, tuning, mixtures, brake biasing... Sure, it looks good on paper. Sure, it sounds nifty. Put it into effect and you could very well have a sloppy-handling, terrible braking, low-traction-blow-the-diff-apart-in-20-minutes piece of expensive Carbon Fiber crap. Just ask the 2001 team....

Our Formula SAE team 2006 was freaking insane... Near everything on that thing is Carbon Fiber, down to the diff housing. No joke. Looks really cool. Advanced suspension, Yamaha I-4 650cc if I remember right. Pushing near 300HP. Yee-freaking-haw! Talk about your acceleration.... And the tone... Man, like something straight out of an F-car... Rev it to 20 grand and you can FEEL the engine... 20 feet away.

Anyway....
10-40 is a better oil for diesels. Not so much for gassers. I typically have 15W-40 in half blend with 10W-30. 15W-40 being the Schaeffer's and the 10W-30 being Mobil 1 Premium Full Synthetic. Works well for me, but gets pretty thick in the winter. If I order more Schaeffer's I'll probably jump on 10W-30. Only reason I use the other is because my dad bought it for the diesels, and its what we have on-hand.

[tercel4wdrules]

Might check for a blocked PCV hose though?

This a very good idea because it might just be pinched down and it's a new hose.

Since Typrus really likes SeaFoam I'll throw it in before changing the oil. Can it be driven a few miles with it floating in the crankcase? Or just run the engine for a few minutes with it and then dump the oil?

Well, I actually met a mechanical engineering major student who does not have his DL and has never driven a car before, but yet he's on the team for the SAE Super Mileage competition and designs parts for the car.

What I was referring to was not oil vapor, but actual little oil droplets spitting out of the engine.

I'm glad I was educated here about 10W-40 oil. Truth be told, I really don't have $50 to spend on a synthetic oil change as much as it is "recommended." I used Castrol GTX on the last oil change. I suppose one substitutes a quart of ATF because of the higher quality of the oil as well as the higher level of detergents present? Am I right? Walmart Supertech? I'll give it a try.

I try to visualize how the clutch disc matches up with the speed of the flywheel when engaged and stuff like that. It really does help with the conceptual material.

BTW, how "tight" should the spark plugs be tightened?

[keith]

Ok, starting at the end, spark plugs 22 ft/lbs. Thats about a 1/4 turn after bottoming on plugs with a gasket, 1/8th turn on tapered seat plugs. Its pretty hard to over tighten them with a regular 3/8" drive ratchet handle. Unless your plugs are anti-sieze plated, use an anti-sieze compound on the threads.

Yes, the transmission fluid has a very high detergency, it will help clean the engine and may free up the rings.

Many will debate the merits of one oil brand over another, but none of them do any good if you can't afford them. Cheap oil changed frequently is better than not changing oil.

I do use synthetic oil in several other cars that I maintain for the family. I save the used oil and used to use it as make up oil in the Tercel, but now that I put a new engine in it, I don't know what I'm going to do with the used synthetic. The Tercel actually used more oil right after an oil change with fresh dino, consumption went down as more used synthetic was used to make up for the loss. It used too much oil to justify fresh synthetic at oil change time.

[tercel4wdrules]

Yes, the transmission fluid has a very high detergency, it will help clean the engine and may free up the rings.

Many will debate the merits of one oil brand over another, but none of them do any good if you can't afford them. Cheap oil changed frequently is better than not changing oil.

I use a spark plug wrench that pivots, that's why I wanted to know how much to tighten the plugs.

You have a very good point about the oil. Changing the Walmart Supertech oil at 3k miles is better than leaving some other, more expensive oil, in too long or even neglecting oil changes all together. Things might change in the future and I might be able to switch to synthetic.

Is there a specific ATF fluid to use for this purpose? I know there are several specs such as Dexron II, III, etc. but I don't know much about ATF so I'd like to know.

[Typrus]

Driving around with the SeaFoam for a while won't hurt anything. I drove 50 miles with Marvel Mystery in the crank with no issue where some said things would fall apart. I've driven 70 miles in a friends car with a full pint of SF in his crank. I wouldn't recommend that on a Terc, what with our 3.9 quart capacity. His was 7 quart >.<

[keith]

Its important to use the correct ATF in an automatic transmission, but for cleaning an engine, I don't think one is any better than another. As for tightening the spark plugs, you don't want to pull out the threads. As long as the threads are in good condition and you don't cross thread a plug, they shouldn't pull out.

Plugs are made from iron, the cylinder head is aluminum. If these two stay in contact with each other for a long time with electricity passing through them, dissimilar metal corrosion takes place, literally welding the plugs to the head. This is why I recommend an anti-sieze compound on the plug threads, UNLESS the plugs have an anti-sieze plating. You do not want to mix anti-sieze compound with anti-sieze plating.

[xirdneh]

quote="tercel4wdrules"]I just discovered that oil is blowing onto the top cover of the air cleaner. quote]


too much oil in the system will do this.