Oil Consumption (or lack of)

The last words from the OPC salesman ringing in my ears as I drove away in my new (to me) 23k miles '99 C4 were 'make sure you check the oil regularly, it'll use about 1 litre per 1000miles' Well, 1500 miles later, the oil level guage on the dashboard has just moved down 1 graduation and a check on the dipstick confirms that the oil level is still close to maximum. I've checked it both cold and warm and the oil is clean so there does'nt seem to be any other fluid in the oil. At the present rate of consumption I'm going to be needing 1l per 5000m. I should say that whilst I dont thrash the nuts off the car, I do drive it hard when conditions permit. So, a few questions 1. Should I be pleased or alarmed? Even the handbook states an oil consumption of 1.5l/1000km 2. The handbook seems to be contradictory. It refers to checking the oil when cold but then refers to an oil check during refuelling and states that the engine must be at operating temperature. So, which is it? Obviously you should wait until the oil has had time to drain back into the sump but should the oil be checked hot or cold or does'nt it matter? 3. How accurate is the dashboard guage? Can you rely on it without checking the dipstick regularly? 4. Which brands of oil are recommended for the 996? Thanks in advance for any advice

Don't worry..... Had a 996 C4 for 2 1/2 years and NEVER put any oil in it between services. Use Mobil 1 - I bought some in France for £20/4 litres and supplied my independant with oil at service time as they charge about £9 a litre! (+vat of course!!!)

1. Pleased. Porsche's figure is not a target, as all cars vary they warn you about the upper limit. 2. I believe it is most accurate when warm. 3. Having established that the guage on the dash roughly matches the dipstick, then you can rely on the dash guage. (If you buy a turbo you have to, there is no dipstick, so it is safe enough). 4. Porsche recommend Mobil 1 0W-40. That's it - only one choice.

I agree with Stuart (again) on 1, 2 & 3. I have found the dash indicator to be very consistent with the dipstick reading. If you try and take a reading before the system is ready, it will give you a countdown time. I think the book says that the fastest readings are obtained when the engine is cold or hot. Hence it will give you a reading when you fill with fuel, because the engine is generally hot, and has been standing for a few minutes while you fill. When hot the oil drains faster into the sump. As for oils, Porsche have a list of approved oils. I couldn't attach it to this post, but you can download it from here: http://www.wrightune.co.uk/downloads/approved_oils.pdf Right-click the link and choose "Save Target As . ." to save it to your hard disk. Having said this, I guess you will be taking it back to the OPC for servicing, so you won't get a choice - it will be Mobil 1, which you can use for top-ups, but I doubt if you will need to.

Oil consumption does seem very variable - I have no idea why - my car has used hardly any in almost a year and 8000 miles but others seem to be topping up all the time.

My 911 was recently serviced at an OPC and returned, filled with Shell Helix Ultra... much better oil pressure readings at low rpm...

Hi, I have the same car (year and model) and don't need to top up between services. I do keep checking though Will

If it's the 5W40 grade I think it is a much better choice for 'older' engines. I switched to Havoline 5W40, and like you, noticed a definite improvement in low rpm pressure. A lot of independents use Magnatec 10W40 for that reason. Although it is semi-symthetic and it isn't on the approved list, I am told this is what Castrol recommend on their advice line.

Hi Richard What do you mean by an improvement in low rpm oil pressure - higher or lower? Mine runs at 4.5 at 3500rpm warmed up and I think the book says should be 3.5 at 3500rpm so I'm not sure if higher is better or not. Presumably more prone to leaks at higher pressure. Just had a dramatic leak from a belt tensioner washer - oil pouring out, change of underpants but fixed FOC by OPC PDQ. Hot Mobil 1 is like water. Hugh

Hugh I thought the oil pressure on mine was a bit low on tickover and low rpm compared to my 993. This improved (was higher) by changing to 5W40 oil. These zero weight oils are like gnats pee when they get hot, and IMHO higher mileage engines benefit from a slightly thicker oil.

I have just had my 996 serviced by specialist and now when hot one of the cam followers is ticking when idling but only for a while. Leave it running for five minutes and it stops. I wondered if the oil was two thin perhaps. It was refilled using Esso Ultron 5 40. It is also ok when cold. Any ideas?

Had the same issue on my previous Porsche - 3.4L 996. Specialists never figured out why the ticking happened or what caused it. Never got any worse. Disappeared after a few minutes warn tickover. Just learnt to ignore it! Bizarre these Porsches! Ian W

Ive never put any Oil in my C4 and have done 15,000 miles. And that's including the oil leaking out of the bottom of the engine on a regular basis.[&:] Si C4