So I just got done doing a full major on my Fiat Spider 2000. It's an '82 with 100k on the clock. Runs amazing well. I've had it for about 20 years and in all that time it haven't burned a drop of oil when I used Castrol Dino 10/30. After the major, I added a high zinc content Dino oil and it used two quarts in about 2000 miles. It's not burning it as far as I can tell..... could the zinc oil act differently from the typical Dino?
Nothing to do with the zinc content, which within typical limits will be actually good for your Fiat tappets. Did you change the viscosity? I think your manual would spec 15W40 which would probably be a diesel spec in a modern oil, Rotella seems to be favoured for the Fiat's of that era. I would check your coolant/oil and make sure you don't have a head gasket leak. The oil consumption is not that bad, but if you had none before, it suggests something has changed that may be worth evaluating further.
I did check the coolant, that was the first thing I did. Happily, I didn't find any cross contamination. I have always used 10w/30 and I believe my owners guide specifies 10w/30. Nothing I did, tune-up wise should have influenced consumption. And there is no new smoke at start up. I think its simply using oil. Oddly, it never used a drop when I used Castrol 10W/30 for the past many years. I guess the question now is whether or not I should continue to use Zinc enhanced oil. Based on my recent learnings, I should have been using it all along.
I am pretty sure you are specced for 15W40 originally, or various single grades dependent on temperatures. The VV211 is a racing oil, probably not the best additive package for street use, usually have less corrosion additives, different detergent levels and such. The 10W30 might be a bit thin as the clearances in your engine open up with time/use, you might try the 15W30 and see if things improve.
I have read that new cams and followers, are the engines that need the hi zinc. Once run in the need is diminished.
Thanks- Will do. I actually just did a bit of research, most are running 15W40 and most suggest Rotella. I wonder if I should change it out now.
I can't imagine its anything other than the oil. Its no leaking out and not in the coolant. The only thing that has changed other than a thorough tune up, belts, pump, plugs, wires, cap rotor, coil, tensioner, valve adj, etc. has been the type of oil. Ill change it this weekend and report back. I appreciate your guidence!
Those that use break in oil (really just like racing oil) suggest a change to the normal oil at about 3,000 miles. So if you have done 2,000 miles already, its not much of a stretch to bring forward the change a bit and fill up with 15W40. I do think the VV211 is a racing oil more in name then chemistry, so other than it being a bit thin on the viscosity it would not present any problems unless you left it in for extended drain intervals. If it is not leaking out, burning with more noticeable smoke or mixing with the coolant, where is it going? I am presuming your car is running well in every other respect? Maybe pull each plug to see if any sign of fouling, maybe a valve stem seal is not doing its job, was damaged on valve adjustments?
Here is a list of the causes for oil to be consumed excessively. https://www.amsoil.com/techservicesbulletin/MotorOil/TSB%20MO-2004-04-03%20Oil%20Consumption.pdf
After reading Streetsurfers guide, I think I'll change it out now. And no, I didn't touch the head. Just adjusted the valves. Good question on where is it going? The engine is running very well. If a plug was fouling, I think I would be able to tell. I had an Audi a few years back that used a quart every 1000 miles. Seemed ridiculous to me for a new car but the dealer said that it was within spec. Where did the oil go? I never got an answer other than them telling me that the engine used oil. As for my fiat, when the light came on and I checked the oil a few days ago, I drained it, replaced the filter and filled it with new racing oil. I think I'll change it out for the Rotella this weekend and see how it goes. Thanks - Ron
Motor Oils are a mixture of three basic components: A) fluid of known viscous properties B) an anti-wear package C) a sitting in the garage package A motor oil consists of about 85% base oil, 6-7% anti-wear, and 7-8% garage. A race oil consist of about 92% base oil and 7-8% anti-wear. The anti-wear package is the ZDDP, Moly, CBN, and friction modifiers. The garage package is the acid neutralizers, detergents, anti-alkaline, dispersants,... How hot does the motor run? How hot does the oil run? Have you run a compression test? Have you run a leak-down test? The lack of detergents in the race oil can allow rings to coke-up and allow oil to seep into the combustion chamber via the cylinders. Counter-intuitively, thinner oils clean the ring package better than heavier oils.
Motor and oil run at typical temps. No changes. No to compression and leak down. Motor runs really well and pulls strong? It's running better now than it has in years.
I have experienced large differences in oil consumption between different oils in the same engine so what you experience is possible. Usually an engine that did not smoke before did smoke/smell with another oil, which was fixed by reverting to the first oil brand and type. Also new oils can "air out" for some time, after a change the level can drop as much as half then stabilize. In the piston bore the oil rings have to scrape down the oil which may be more difficult with some oils... So counterintuitively thicker can be worse. Some people say thinner is actually worse because more oil will exit from the bearing into the bore... Two sides to every argument. You can reason all day long and not reach consensus... Or as advised, just revert back to your earlier oil and call it a day. Zinc is not too likely a cause or a requirement. As i have read it, it's mostly important for flat tappet engines such as pushrod V8s that often are a little underlubricated in that area. I don't believe the Fiat engine particularly requires it.
One more thing. You mentioned its running better than ever. Maybe you are now running on average higher revs than before, or using rev ranges that previously were avoided? In a car with piston ring issues, oil consumption at the highway can be up to five times higher than in city driving.
This is not uncommon and I have experienced it myself. Strangely enough my Quattroporte 3.2 uses far more oil with the factory recommended 10w60 then with the now used 5w40. In my case it is the piston oil rings that can't handle the thicker oil which is common on the Maserati 3.2 V8. There are also differences in oil consumption between the different 5w40's I've used. Oils clearly have different qualities although with same viscosity.
Hmmmm. Very interesting, I think you may have just solved the mystery. I recently purchased a lake house which has changed my typical commute from back roads driving to 90% highway. I changed the oil at around the same time I started my new commute. I bet this is the reason for the consumption. I wonder if I should go to a thinker oil now? Thanks so much!
