elgy

I am fairly active on the 928 and 944 forums but a noobie here... bought a boxster Monday.
It was outside of town so about a 40 kilometer trip home, mixed highway and city and it ran perfectly.
It is a Jungle Green 2000 5-speed with about 84,000 miles, originally from Florida but has been in the Montreal area for the last 14 years. I discovered what previous owners didn't know; you can switch the odometer and digital speedometer to metric.
Here are couple of pictures taken by the previous owner.





It is in generally good shape though the seats are badly cracked, I have bought seat covers as a short term solution. There are no oil leaks so the RMS is good. It seems that it has the double row IMS bearing and there is no indication of problems there.

Now the problem. First thing I did was change the oil and filter... the car has hardly been driven in the last 4 years and the oil was short on kilometrage but long on time. I checked the old filter for metal filings and it looked just fine. I torqued up the drain plug and the filter then put in 8 litres of 40W oil. Checked the dip stick (I have just been learning about the electronic level checking, as you will see) and started the engine... all was well. Checked underneath and there were no leaks. I drove about 3 kilometers and checked underneath after I had finished my shopping... no oil leaks. I then took the long route home via a couple of highways. After about 10 minutes at or around 100kph the check engine light came on. Oops. I was not in a position to stop immediately and the CEL can mean all sorts of things that are not fatal... no oil pressure light, temperature remained steady and the engine was just humming along. When I was able to stop I looked underneath... no oil leaks. When I checked the dipstick just a drop of oil on the end. The electronic oil level indicator was flashing on one bar meaning low oil. I waited, checking the level electronically and it came back up to 2 bars above empty. So there was enough oil in the engine. I ended up calling CAA to get it home (the shame of it). This morning the electronic level was up to 3 bars and the dipstick indicates about 3/4 full.
I removed the drain plug briefly to sample the oil... looks good no water. I drained a bit of coolant... ditto no oil and no oil in the overflow tank. No oil coming out of the exhaust. So, what's up? I can understand that the oil went down on the dipstick after some driving as the filter and other parts of the engine filled up, but I put in almost he full amount needed (8 liters instead of 8.25). I am wary to add more oil, but both measuring systems indicate that it can take perhaps another liter. Also even when the oil level came back the CEL remains on. I have not started the car since doing all my detective work today as I would like to have an explanation before turning the key.
Any help or suggestions happily received.

Macster

While you put in 8 liters of oil the engine the correct amount to bring the level to full (but not over) may be closer to 9 liters of oil. IIRC each line on the oil level display is very close to 1/4 quart so down 2 or 3 lines means the oil level is 1/2 to 3/4 of a quart below full.

The procedure for changing the oil is to with the engine up to temperature drain the oil for 20 minutes (the DFI engines require a 1 hour drain) then add a specific amount of oil. I don't recall the amount. The techs tell me it is tied to the VIN as changes during production run can cause the oil volume necessary to bring the level up to full to change. (When I changed the oil myself I filled up the oil filter housing with oil, then dumped what remained of the bottle in the engine along with 7 other quarts of oil then used the dipstick to double check the level was ok.)

After the oil has been added then the electronic oil level system is used to verify it reads the right level, which should be full/max.

IOWs, the electronic oil level measurement system is not used to measure the oil to be added to the engine only to verify that it reports the level correctly full when the oil has been drained and refilled according to the factory guidelines.

The only time I used the dipstick with my 2002 was to check the oil level after changing the oil. I also counted the number of empty oil bottles. Twice. (This was doubly important when I changed the oil in my Turbo as it had no oil dipstick, only the electronic oil level measuring system and for this to work the car had to be level, the engine idling, and the engine up to some minimum temperature. So one wants to be darn sure the oil level is correct before he fires up the engine to confirm the electronic oil level measurement system is working.)

The electronic oil level measurement system has (at least) 2 modes of failure. One is the wire breaks. The techs tell me in this case there is no reading. (The sensor works by measuring electrical current resistance in a looped bare wire that is submerged in the oil. If the wire breaks there is no reading.) The other way is if this loop of wire comes loose from the hook at the bottom of the tube. The loop of wire then can move about and if not submerged completely will result in the resistance values varying. This can show up as the level fluctuating while -- if one has one available -- the dipstick reading shows the oil level ok.

It reads like the electronic oil level system has a problem and can't always correctly measure the oil level.

Oh, the CEL may be unrelated to the oil level issue. But you need to read the code associated with the CEL. Post here and someone will offer some detail.

elgy

Thanks for the response. I just got off the phone with a local Boxster owner, James, who reassured me. In talking to him I remembered that the parking lot where I stopped after the CEL came on was not level... my driveway is, which likely explains the discrepancy and the very low initial reading when I stopped last night. I was so stressed that the sloping parking lot didn't register as something important, although normally I would have realised that. James has diagnostic equipment so Saturday he will check my codes for me.
Being nervous about starting the car today gave me some time to do some more maintenance catch-up... that's a good thing.
Tomorrow I think I am going for a drive!

Geza

Congrats on the Boxster purchase, from a long time Boxster owner who just bought a 928 ('87 Auto - GPW). My first thought was that the oil was under filled some. Let us know how it goes, and good luck!

Macster

Parking on an slope can really affect the oil level reading. It is rare I parked my Boxster on severely un-level ground but there so happens to be a heavily crowned road that runs by the main post office in town and parking in front of the post office has the car severely tilted down on the passenger side. The first time I parked in front of the post office and as is my usual habit checked the oil level before leaving the reading was way low, down to nearly the min bar when I keep the level up towards the max bar. But because I check the oil level often I realized the low reading was an anomaly due to the car not being level.

(My Turbo in the same situation would not allow an oil level measurement to take place.)

So check your car's oil level on a relatively level surface and if the reading is pretty consistent the low reading was a car level issue and is not due to a problem with the oil level sensor.

Be aware that other things that can affect the reading is how hot the engine got before it was shut off and how long the car has sat since the engine was shut off.

I made it a habit to never bother to check the oil level after I had started the engine until 1) The engine was fully up to temperature, and this can take 15 or more minutes of engine run time; and 2) the engine then had been off minutes. The time it takes to fill the gas tank is a good span of time.

Another protection against inconsistent oil level reading results is I never checked the oil level unless the count down timer started at 5 seconds. But even this presented a problem. There were times when I would park the car after a short drive and when I got back in the car the count down timer would start at 5 seconds. However, I knew the engine was cold, and I also knew I had not been in the store, often a convenience store, that long -- sometimes just a minute or two -- and dismissed the 5 second count down timer as an anomaly.

I quickly adapted to using the electronic oil level measurement system in my Boxster. In the Turbo I had no choice as it did not come with a dipstick. But it was a more sophisticated system. No reading if the car was not level. The engine had to be running and the engine up to temperature.

My new JCW had an electronic oil level measurement system -- but it takes a minute of 1K+ "idling" before it will produce a reading -- while my new Hellcat has a very hard to read dipstick.

elgy

So here is the summary... there was no problem.
When I saw the CEL I over reacted. Since most new problems relate to the last thing you did... in my case the oil change I immediately decided it was an oil problem. The CEL error was a totally unrelated coincidental incident (that I reset with my generic OBD reader). Parking in a slope with my brain in panic mode I saw a problem where there was none. Today all was well... the dipstick right at the top and the electronic level also. I returned to the same sloped parking lot and lost 3 bars from the electronic level indicator.
So the lessons are:
1. (As IBM used to say) "Think" (before panicking)
2. Don't measure the oil on a slope.
3. Unlike in detective stories... coincidences do happen.

Shawn Stanford

Relax. Just drive it and beat the hell out of it. You'll both be happy.