Since my 2003 AP1 was new (it had 10 miles on it when I purchased it. I have always had an intermittent oil consumption with it. I.E. I drove it from my home in VA to Asheville and it used .6 quarts. I topped it off and went on the drive at the meet often in the V-TEC mode and then drove it back home and it did not use a drop.

Even Billman agrees that the most logical explanation is "sticey rings" that allows blow by.

On the way back from this year's S2K Days in KY, I turned 182K miles on my AP-1 . I am about to leave on a road trip to scope out next years S2K Days venue, with Ken next Sunday. Before I go I am going to try using BG's Engine Performance Restore product to see it that will solve the problem.while flushing out the current oil. Hopefully, if I have stickey rings that will solve the problem? Then I will change the oil with Mobil 1 10W40 High Mileage oil and it will be interesting to see if it solves the problem

 

Generally speaking conventional 10w-40 oils are the worst oils made, they use too much viscosity index improvers to get that big viscosity spread. Viscosity index improvers have poor or no lubricating properties, and they break down with use so conventional 10w-40 has been shunned for a long time within the industry. Mobil1 oils have always been great at cleaning engines though in their synthetic line-up. A true synthetic 10w40 is fine though as it does not need or use much VII's, unlike the conventional version.

I remember experimenting with thicker oils on my Ap1 and they did not help my oil consumption numbers, I was running 5w-40.

Mobil1 makes a great 0w-40 oil, but 5w-40 would be good, or 10w-40 if you want to try the high mileage. Honda recommended a 5w-40 oil knowing that it would automatically be a synthetic oil regardless of brand used, and thus it would have proper cold temp properties. I don't know if the Mobi1 High Mileage is synthetic or if you will run your car in cold temp weather. The high mileage is always worth a try though, it would be a good experiment I guess.

I think ovalized cylinders is the real issue with Ap1 oil consumption, and cylinder bore issues. It is one reason Ap2 s2000's use much less oil as they had superior cylinder boring techniques from the factory which Ap1's did not. I don't think it is a sticky ring issue as much, but always worth a try to free up the rings, it can't hurt. BG products are great and definitely worth a try if you have piston ring deposits. Keep us posted on your results.

 

I've had my 03 since new (7 miles on it) and it has always used a bit of oil. It has always used about the same amount I haven't had any surprises were it went way down and I always catch it before it is down a significant amount I would say it is less than a quart every 3,000 miles. It has 78,000 on it now and if anything it seems like it uses less than it used to.
While we are speaking about oil there was another thread in another forum here were people were saying that they change the filter every other oil change. Makes no sense to me as the filter has dirty oil in it but I seemed to be in the minority, what is the opinion of the Vintage Folks?
Matt, I've always used the recommended 10W30 in my S.

 

Honda used to recommend oil filter changes every 2nd change. Certainly the filters are designed to run a long time since S2000 oil change intervals are often on the short side for many owners, so the filters can go the distance.

But like you said Rob, you are leaving some dirty oil in there to dilute with the new oil. You aren't saving much money either skipping an oil filter and your new oil gets degraded a tiny bit more because of it. I might only consider it if I was only driving 1000 miles a season or a very low amount, with regular driving use I would change the filter on each oil change.

 

I would never do it no matter the mileage to me there is no point, I've always been a big proponent of changing oil/filters even before the intervals are up.

 

Tech Tips on Oil from my personal Notes (More than you ever wanted to know)

Checking the oil, what the book’s say:

1. Owner’s Manual: “Check the engine oil level every time you fill the car with fuel. Wait a few minutes after turning the engine off before you check the oil.”

2. Honda ESM Service Manual ‘00, Ver. 1.3.7 (Service manual on CD): “Park the vehicle on level ground and turn off the engine. Allow the oil a few minutes to drain back into the oil pan so that the dipstick will show the actual level.”

3. Helm’s Honda Service Manual ‘01: The subject is not covered. It begins with changing the oil.

The books presume it will be warm if you just drove it into the gas station or a service bay and they are telling you to wait for it to settle into the pan. Naturally, if you check it cold you will have the most accurate reading.

How much? All the sources agree:

4.8 qts without a filter change.

5.1 qts with a filter change.

5.9 qts for an engine overhaul.

Consumption: Honda states that due to the high performance nature of the S2000, its engine can consume a quart of oil in 1,000 miles when driven at high rpm. So Honda suggests S2000 owners follow these guidelines:

Checking: Check the engine oil level every time they fill the fuel tank.

Dipstick Reading: Be aware that the oil dipstick goes through the cylinder head, so engine oil draining back into the oil pan can wet the dipstick and give deceptive readings. So look at both sides of the dipstick, and then use the lowest reading.

Note: The S2000 needs 5.5 quarts of oil. The distance from L to H on the dipstick is 1 quart. Thus if you are down 3 X’s you are down 3/5ths or 0.6 of one quart.

Refilling in Break in: During the first 600 miles (the car’s break-in period), the engine may consume even more than a quart of oil; customers should add Honda 10W-30 or other high-quality petroleum-based oil of that viscosity to the factory-fill oil, as needed to restore the oil to the proper level.

Proper Weight: For optimum fuel economy and year-round engine protection, customers should use only the 10W-30 weight of engine oil. This is a revision from the 5W-30 recommended in the owner’s manual.

Break in Oil: Because the piston rings, piston rod bearings, cam bearings, and crankshaft main bearings continue to “break in” during the first 5,000 to 7,500 miles, factory-fill oil is provided in the engine of the delivered car. The factory-fill oil has special additives, so it should be left in the engine until the first oil change: 7,500 miles, under “Normal Conditions.” [Reportedly, the oil is slightly thinner than normal and contains more Molybdenum to provide the "slipperiness" that thinner oil may lose.]

First Oil Change: If the oil is changed at 3,500 miles because the car was driven under “Severe Conditions,” replace the factory fill oil only with 10W-30 petroleum-based oil.

Synthetic Oil: Do not use any synthetic oil for the first 7,500 miles. Synthetic oil is excellent protection for the car’s engine, but it should not be used before 7,500 miles since it will not allow the rings, bearings, etc. to “break in” properly. Honda claims that synthetic oil is too slippery to seat the rings properly (seating the rings refers to the rings shaping themselves to the precise size of the bore). The lubricating qualities of synthetic oil coupled with the engine design prevent the rings from properly seating if you switch to synthetic too soon. Also, the break-in oil has special additives, so try to keep it in for 7500 miles if possible.

According to one source, based on a research document, if you are switching from 1 synthetic to another, you need to run conventional oil again between them the two synthetics. Synthetics are compatible with conventional oils, but synthetics are not compatible with other synthetics. The additives do not mix well.

Variation in Engines: Some S2000 engines will consume more oil than others depending on the tolerances inside the engine. The rate of oil consumption will taper off between 5,000 and 10,000 miles.

One S2000 owner remarked (edited): Lets clear up some misconceptions. First, it is perfectly normal for the S2k to burn oil. Just because a particular S2k does not burn oil, does not mean that engine is better, faster, or will be longer lasting. Some people seem to gloat that they burn almost no oil, while there are those that are peeing their pants when they consume a quart every 1000 miles. There is nothing to suggest that one engine is superior to the other. A Honda engineer commented on the subject and mentioned there was an article at SpeedVision.com about how much oil was consumed in a F1 Car; it said that F1 cars consume 17.5 gallons in a 24 hour race. Honda cars are not designed to burn oil but there is a break in period where they might. The S2000 has a longer period, accept it.

2004 Model: Based on all the early reports, the excessive oil consumption issue with new S2000 has been corrected. The owners of 2004 models report it has been solved. The only insider information we have is changes were made to the block and all blocks either new or replacements would use the new design.

Loose Oil Filler Cap: A number of owners report the Oil Filter Cap Vibrating Off if not tighten down good. The speculative causes range from the gasket mis-aligning when being replaced, engine vibration loosening, and just sloppy work by the dealerships. Honda dealers have seen this several times. The oil cap comes off or is left off and then falls down on top of the transmission. It makes contact with the "tunnel" and makes a very bad vibration sound.

Finding Missing Oil Cap: If its missing would suggest a bent coat hanger or something to reach behind the engine and "sweep" over the top of the transmission. Your friendly neighbor hood Honda dealer would probably help by putting the car on the rack to better access the side of the transmission.

Oil Dip Stick Popping Up: Some owner’s report finding the Dip Stick Has Popped Up, thus allowing oil to be blown out into the engine compartment. Reportedly wiping the rubber o-rings before reinserting may help and ensuring it is fully engaged.

Replacement engine block - According to a Honda engineer, all the new engine blocks from Honda after 2003 come from the same stock for both the 2.0 liter and 2.2 liter engines. The model year 2000-03 engine block is no longer in production. If you have an early 2 liter engine replacement you will have the F20C crank, rods, pistons, and other internals installed in an F22C block. One of the benefits is the new block removes the oil burning issues.

Down a quart - Don’t panic if you are one quart low, the lowest mark on the dipstick. If the level never changed from this, you could drive till the next oil change. One qt. low (or anything above that up to the "full" mark) is within the acceptable operating parameters of most engines. This is where you "add" some oil. This is not where the engine begins to suffer. One knowledgeable owner reported running the S2000 down to 2.5 qts remaining! Even at this low level, it did not turn on the oil light nor the CEL. The oil pickup on S2000 engines is nearly dead center at the front of the pan. Lateral maneuvers of the car does not take a lot of oil away from the pickup. As long as the oil sump is drawing oil, there will be pressure and oil getting pumped to all the right places. But please don’t try testing this yourself.

Caution on over-filling - This according to one owner: I’ve done more oil sling tests than you can figure and between the half quart low, and a one-quarter width over full marks,, you rob you of about 25 hp. So don’t think 6 quarts is ok, even though the car will hold it; unless you drive like an old lady and dont care about power.

 

Good stuff Dave. I wasn't aware that synthetic oils are not compatible with each other.
I remember back in 03 when I bought my S when to change the oil for the first time was highly debated. There were two camps one saying it should be changed within the first 1,000 or less miles and another said that due to the break in oil you should go at least 3,000 or more. Looking at my records I performed my first oil change at 4.550 miles.

 

Thank you for the input.

Tomorrow I plan on running the BG Engine Restore product in my AP-1

Then I will change the oil with Mobil ! 10W40 High mileage with an OEM filter. I am leaving on Sunday with Ken F to drive out to Eureka Springs, AR to scope out next years drives routes for next years S2K Days . It will be a little over a two thousand mile round trip. So it will be interesting to see if my oil comsumption issue goes down?

 

That will be a good test, all the best with the trip and car.

My Ap1 would burn oil like most of them always did. On a trip to the Dragon the car did not burn oil on the way there (highway steady state driving) or on the way back, but when I was at the Dragon it burned oil with all of the cornering and high rpms driving and shifting, etc.

 

Oil level anywhere in the range indicated on the dipstick is fine -- no need for it to be at the top level and continuing to top it off may be wasted effort as some engines will use a bit of oil, reach a stable sweet spot somewhere in the range, and just stop using oil. Keep filling to the F level and the process just repeats making you think the engine is using more oil that it really is. Again this is some engines but regardless if your oil level is between the marks leave it alone and see what happens next.

-- Chuck