NoHander

As of 3 months ago I became the proud owner of a 2003 S2K AP1 that had 62,000 miles. First thing I noticed was that it was using conventional oil so at the first change I switched it over to synthetic. After a couple months I began to hear a rattling noise in the engine and, after checking the oil, saw that the dip stick hardly showed any in there. It was burning oil. Took it to a mechanic that's well trusted by good friends of mine since I am mechanically retarded and they recommended switching BACK to conventional being that the viscosity and thinness of the synthetic oil was causing the problem, so the thicker stuff was needed. Knowing it was bad to switch back I voiced my concern but was advised that because of the improvements made by today's oil, it would not harm the engine. Yes, just as you're doing right now I myself raised an eyebrow. So here are my questions:
Are AP1s prone to burning oil when using synthetic?
Was the change back to conventional a mistake?
Will I still be able to switch back to synthetic without damaging the valves or seals?
Is the oil burning a temporary problem?

I use this are as a daily commuter and just want to take good care of the car as I'm sure you all know.
Thanks.

redlineracing

Ok,I'll chime in.

Lot's of good oils on the market today....and most folks would agree that full syn is a better choice for most cars.

I personally would not change back-and-forth.Pick a good brand of full syn and change it as often as you can afford.

\rlr
carolina

slalom44

First of all, Welcome to S2KI and Congratulations on your new purchase.

The AP1 is known to burn oil. Some more than others, but this is very common with this engine. Some synthetics have been known to burn more than others, and you might want to try switching brands to see if it changes your oil consumption rate.

Personally, I think you are getting advice on oil from a mechanic that doesn't know much about oil. He implies that synthetic has a lower viscosity than conventional oil. That is a very bad and misleading assumption. Synthetic oils typically have lower viscosity when cold, not at operating temps. Thinner oil during startups will give you oil pressure faster and is much better for your engine, especially in the winter. But that's not what causes oil consumption.

If you're using Mobil 1 10W-30, my opinion would be to switch to another oil that is more shear stable and has a higher viscosity at operating temps. A good choice would be Pennzoil Platinum 5w-30 but there are plenty of others. This will give you a little more viscosity than Mobil 1. But don't expect dramatic reductions in oil consumption - your enging probably burns oil, and you can't do much about it. You might want to check/replace your PCV valve - it's inexpensive and if not working properly can cause excessive oil consumption.

But if you want to stick to your mechanic's advice, IMO there is no problem switching back and forth. But don't be surprised when the oil consumption doesn't go away. And if he's trying to talk you into using an oil thicker than 10W-40, you might want to consider ignoring his advice. Increased viscosity doesn't mean better lubrication. I have an '03 S2K and I'm using Amsoil 0W-30. At 205,000 miles, my engine still runs great.

redlineracing

Thanks for using Amsoil products.

I use Amsoil Sig Series 0-30 oil in all my "gently-enhanced" cars.

\rlr
carolina

NoHander

Redline - Thanks for putting in your two cents. Dual note on not flipping and flopping on oils. This is the first car I've purchased where I ACTUALLY want to take care of it, so asking every question possible will be posted and the many two cents of others will be greatly appreciated.

Slalom - Thanks for taking the time with that informative post. Been reading that the oil consumption has been a problem with the AP1s. I take it your S2k still burns oil? if so what measures have you taken in order to cut back on its consumption? I will try other oils but will stay with synthetic since that's the way to go.

kundanp333

I keep a quart in my tool well. Just in case.

SpitfireS

If an engine is very low on oil, a spirited drive including some spirited cornering can create oil starvation, leading to bearing damage, etc.
The amount of damage depends on the quality (& temperature) of the oil left in the engine and the load (creates temperature) on the parts without oil.
Better oil = less damage.
Less load = less damage.

The most important question: did the ratteling noise stop after adding oil?
Answer: yes = you're lucky
Have fun driving your car and keep an eye on the oil level, check at least at every fuel fill-up.
Answer: no = you probably have engine damage

Every synthetic / dino (conventional) oil debate should start with a defenition of the word synthetic

On a scale 1-10, 1 being catastophic, 10 being the very best:
Any oil = 8 - 10 (*)
Low oil = 1 - 3 (*)
No oil = 0

(*) = depending on the type (as you see there is little room for improvement)

And you can change back & forth as much as you like.

slalom44

My S2K doesn't burn as much as many others. I burn around 1 quart every 5,000 miles. It's been quite consistent over the years, but it does vary with driving style. The more VTEC, the more oil consumption.

Hard right cornering reportedly causes oil consumption in AP1s due to the baffle design of our head cover at the PCV valve. Some people have suggested using a 2004 head cover and others have installed "Krank Vents" (do a search - there's plenty of info here). There's also some discussion about rigging up a Toyota Supra PCV valve as well as other variations. These options are worth considering if you do a lot of hard right-hand turns.

I'm tempted to try a different PCV valve, although I'm not sure how much good it will do me since I do a lot of long distance driving and my car doesn't see too much heavy cornering. I get a Used Oil Analysis (UOA) with each oil change, so I know my engine is holding up very well and the top-off oil helps keep my oil additives healthy with my extended oil change intervals.

JackS

Can anyone think of a reason that a change to 10w40 couldn't/shouldn't be used in an AP1? It would seem that in the more temporate months of the year, this would be positive and oil burn would decrease and I would assume compression would go up?.

deepbluejh

It's not going to flow as well at operating temperatures. I would definitely stay with the 30 weight spec.