Do I have RMS?
 

Hello all. I have a 2000 Boxster S 6-speed manual with 121K miles. After an oil change I had a significant cloud of oil at start up but, car drove fine (lots of power, good temp, no noises). I drove 85 freeway miles with no visible smoke, even when I stopped at lights nothing visible with temp and power looking and feeling great. I parked it and came back 2 hours later and the initial smoke again but performed fine. When I returned home I plugged it into the computer and it came back with both O2 sensors being bad. Then I check the oil and it was essentially gone, barley registered on the stick. No visible oil leaks underneath. Did I burn through it all? Do I have an RMS issue? I've parked it since. Thanks for any help you can provide.

Your oil was likely not essentially gone. Not registering and no oil are completely different. Why did you "plug it into the computer"? You never mentioned seeing a CEL?

Are there any oil soaked areas under the car?

How much oil did you use for the fill?

And yes you do have a Rear Main Seal (RMS); whether or not it's leaking remains to be seen. The first step is to look at the underside of the car!

shadrach74,

Thanks for the quick response. Let me clear up some of your observations. I'm aware of the existence of the RMS, I fat-fingered the keys and launched before I could finish the title with the word "problems". As to your last comment, ". . . look at the underside of the car!". If you will look the fifth to the last sentence I indicate that I did just that. So, with that clarified, I used 9 quarts as well as a new filter. Any thoughts?

I don't see any way that an RMS leak could in any way affect what comes out of your tailpipe. Its sole purpose is to keep oil from leaking out of the engine altogether.

I'm betting the clouds you see at start up are normal. My car had an RMS leak when I got it, but a quick glance underneath did not reveal it. If I were you, I'd find a way to get it on a lift and verify its completely dry. A qt in 85 miles is a lot of oil and I have my doubts that it's leaving via the exhaust.

What does your coolant level look like?
If its higher than normal and contains oil resedue, you have a problem.....
Was the engine cool when you checked the oil - it sometimes takes 10 minutes for the oil level to stabalise after a hot run.

Thanks for the reply. I didn't check the coolant for level or contamination, I will when I get home tonight. Yes, I checked the oil the next day. Both the dash oil level gauge and the manual stick barely indicate a reading. Somehow I misplaced ~9 quarts of oil in 170 miles (85 each way). I believe my nest step will be to drain the pan and see how much is there. Assuming the coolant is OK and the oil drain produces a couple of quarts, I suspect I have a hosed RMS.

Thanks again for the reply. No, it is definitely normal. In the two years I've had it there has never been that kind of discharge, I mean it will produce smoke like a 1930's locomotive going uphill. Also, it was ~9 quarts in 170 miles (sorry, the 85 miles I reported earlier was one way). What baffles em the most is the lack of evidence underneath as well as the way it still has lots of power and stays cool. Perhaps I dislodged a section of the fill pipe? I don't know but, I'll keep digging.

Thanks for the reply. I could be looking at two problems that coincide.

OK that's different. In reading your original post, it seemed as if all was normal while driving with just a nice plum of smoke on start up. If your putting off a smoke screen under load, then it could be a few things. AOS system is where I'd start. Check the plugs for oil fouling. The AOS has a diaphragm that controls the vacuum applied to the crank case, if it splits, vacuum is no longer controlled (read full engine vac). Under the worst scenarios, the AOS actually sucks enough oil from the case through the intake and into the cylinders that the engine will succumb to hydraulic lock (this can happen on radial engine aircraft as well though not for the same reason, but I digress). Probably not the best idea to keep driving it. Find a shop or start researching on the internets.

Just want to clear something with what you are saying. If there is oil on the dipstick and you also say one bar or the lowest reading on the readout in the gauges then you are down 1 liter not 9. Dipstick reading displays the amount of 1 liter not the total fill in the sump/oil pan.

I agree and mentioned that in an earlier post. Liters, quarts...8.5, 9... the reality is that not showing oil on the dipstick and being "almost" out of oil are vastly different. ;)

Thanks for all the help, that is a load off my mind that it may not be catastrophic. I appreciate your pointing out the possible culprits. I'm definitely taking your advice to park it, it is sitting on a pair of full length ramps as we speak. When I, or a qualified mechanic, find out the cause I'll post it. Take care.

Thanks for the heads up, Shadrach74 pointed that out as well. I guess seeing the unusual smoke, combined with just having the oil changed and verifying the level, and then seeing nothing but a drop at the bottom of the stick I panicked. After taking a breath, and a couple of JD's on the rocks, I am formulating a plan of attack.

It sounds like the oil separator is bad. We had the same problem and changed the separator. Fixed it right up.

The JD is a good start. Look at it this way, whatever is wrong, it's likely not that serious. If the car felt good and made plenty of power with no odd noises, than it's likely something relatively painless! Good luck!

Sounds like you are down a quart of oil. The 2k takes over 9 quarts. Put some oil in it so it is at the max and see if it goes down after you drive it.

The RMS seals the output shaft between the engine and transmission, it has nothing to do wtih the engine operation. If you have an RMS leak, you will find drops or puddles of oil under the car coming from the area where the engine and transmission mate. If you can't find any evidence of oil leaking under the car then your RMS should be fine.

It is normal to have white-blue smoke on start up as long as it stops in 1-2 seconds.

If you have huge plumes of white smoke when driving, then the air-oil separator is bad. It will look like a James Bond smoke screen for a few moments and then clear up and be fine. Then later this will happen again without being related to anything. If you ignore it, it will occur more frequently as the engine burns oil that should have been recycled back into the engine. The engine will continue to run fine.

I'd top up the oil level and drive it. Keep an eye on the symptoms listed above while keeping an eye on the oil level and proceed according to what you find.

Thanks. I think you hit it on the head, everyone else seems to lean that way as well. I plan on dong just that this weekend. Hopefully that will determine the culprit (AOS).

Add a quart of oil. Are you sure you put nine in? It's easy to lose count and 8 quarts sometimes register as almost full until you start the engine and fill the oil filter.