bovien

I noticed, that when I use Mobile 1 5w-50 I get a lot more chain tensioner rattle at startup than when the car has had an oil change at the OPC. They tell me they use Castrol 0w-40.

When I've used 5w-50, I get the LOUD chain tensioner rattle maybe half of the times I start the car after sittennmore than a day or two, and it lasts maybe half a sec or a bit more, where since I had the oil change at the OPC, it's maybe one fifth of the times I start the car and it's only for a fraction of a sec.

Does that make any sense to any of you guys?

RAudi Driver

What is OPC?

bovien

Official Porsche Center

sixtyfiver

I notice OPC fills oil to top mark of oil level, possible you are putting a bit less when personallly doing oil change . After reading this post, I think I noticed the same thing as you have and now realizing it may be the amount of oil OPC utilizes.

bovien

Well thought. However, I drain into a bucket with a measure, so I know exactly how much to fill. Also are particular with it being filled. Unless the tolerances are very fine, I don't think this is the reason. Bu again the small difference in oil viscosity doesn't sound all that plausable either..

rbahr

Hi All,

I find that there is good information on lubricants at www.bobistheoilguy.com - no affiliation other than using them when I have questions...

Ray

noro

Thicker oil takes longer to make its way into areas where its natural pressure has to expand and push pistons of sorts... example being chain tensioners that operating from the residual oil pressure.

bovien

Agree. But isn't that the opposite situation? My thicker oil would take longer, hence less chain rattle should come from 5w-50?

JB911

I've been running Mobil 5W-50 since I first got my car, and drained the 0W-40 because in Fl the 5W-50 suits the weather conditions-in cold climates there is an advantage with the 0 viscosity, for me there really is no advantage since we don't really get bellow 40F if we do these days-
I always let the oil drain as much as possible during change, and when filling with filter it's about 9 1/2 quarts. A good reading of oil level is only accomplished after a thorough warming, with a hot engine. Might not be the case with some owners, but if you don't have a fully hot engine and check the level when it's only warm, the dash will show a low level-so someone might panic and fill more. Then when you check again later with a hot engine it will show overfilled-might not be relevant to your experience but I like to point this out.
So I've had no issues with 5W-50 and seldom hear the "death rattle"-others have pointed out that the 5W-50 also helps suppress the puff of smoke at start up-

Exon Mobil are of course rooted in Standard Oil, going back more than a century. They and the Germans were involved with technology exchanges/cooperation in synthetics even before WWII-Standard developed tetraethyl octane for aviation gas(150 0ctane, the only thing that eventually made possible the high output aircraft engines)The German scientists and engineers were very happy to acquire the technology through their cooperation-check out Antony Sutton's books on the subject

But in the 80's Mobil did get in trouble when they introduced synthetic aviation oil for piston aircraft- deposits/additives were found to have dislodged impurities that clogged engines and people died, lawsuit brought the end of synth oils for piston/aircooled in current aircraft-and I think they all stuck with mineral oils since then.

Anyway, the oil debates can go on forever as always pointed out in forums- a 0W-40 oil should get moving sooner at extreme cold temperatures than the 5W-50, check their specs. Mobil also makes a 0W-50 but is racing only so you shouldldn't keep it in very long, and it's expensive. Here, 5W-50 on sale at Napa is only about $5.79, I like it-

noro78

ok confused... are you getting more rattle with 5w-50 or 0w-40?

Macster

A bit of noise at start up is normal. A half a second or so is normal. Lots of chain and valve hardware and the valve hardware is a long ways from the oil pump, about as far from the oil pump as it can be and still be in the engine.

Ran Mobil 1 5w-50 oil in both my Boxster and 996 Turbo for 5 years or so. Switched to it because while it doesn't get very cold where I live and drive it gets plenty hot. 100F+ are not uncommon.

(But it doesn't have to reach triple digits for the oil to get hot. With my Hellcat and with an oil temperature display in just mild (70F) ambient temperature and just driving around town normal stop and go driving over the span of some minutes can have the oil temperature up to 230F. (With a loaner Macan in the same conditions I saw even higher oil temperature.) The Hellcat engine as per Dodge gets filled with Pennzoil Ultra Platinum 0w-40 Full Synthetic oil. Might add that even at 230F the oil pressure at idle is in the 38psi range, down a few psi from what it is at 212F. A bigger factor in oil pressure is the difference in RPMs. In D the oil pressure is say 40psi but if I move the shifter to N the RPMs go up maybe 100 RPMs but the oil pressure climbs by 5psi.)

With 0w-40 or 5w-50 oil I never noticed any change in engine noise at start up or at any other time. Even though the Turbo had an oil pressure gauge I couldn't tell by it if the engine had 0w40 or 5w-50 oil in it. (This was when I ran 5w-50 in the summer and 0w-40 in winter.) The 5w-50 oil is not really thicker at higher temperature it just has better high temperature high sheer numbers.

Now both engines would be a bit more noisy upon cold start as the miles on the oil got closer to 5K miles. But this was the case with 0w-40 and 5w-50 oil. Also, as the oil got closer to 5K miles both engines were more prone to smoking upon startup even though I was well aware of what contributes to this and my habit was to avoid using either car in such a way to have it more likely to smoke upon cold start.

With these engines it is important the engine be up to temperature and the proper oil drain interval be used. For my Boxster and Turbo I believe the drain interval was 20 minutes, but for the newer engines this was increased to 1 hour. There is even an overnight drain interval recognized.

The temperature of the engine and the drain interval are important as there is a specific amount of how much oil to then put in the engine. (For my Turbo it was 7.8l (approx. 8.25qts).) The techs have a digital readout on the engine oil gun so they know how much oil was put into the engine. They they start the engine and let it run long enough to get the oil hot then check the oil level. This is used to confirm the digital oil level system reports the proper level based on a known amount of oil in the engine.

Cold start engine rattle amounts can vary depending upon how many miles the oil has and how the car was used prior to the shutdown. A short trip with the engine still cool can result in a quieter restart as the cooler oil doesn't drain away as readliy.

Park the car after a hard run and the heat load from the very hot engine can heat up the oil even more than it would be otherwise and as a result more oil can drain away and the engine can be noisier next start.

I always tried to avoid short trips and to if I had been driving hard -- or just coming off the freeway -- to take a more round about way home or to my destination to give the engine time to shed the considerable heat load it had developed.

For the 996 Turbo the owners manual called for a 2 minute idle time before shutting off the engine and I followed this. This idle time was to give the turbos time to cool down a bit as they were oil and exhaust gas "cooled". At idle the exhaust gas temperature is as low as it can be and this works to remove heat from the turbos. This helps prevent the turbo heat from "cooking" the oil in the bearings.

Last but not least: Might mention the Porsche techs at my local dealer recommended the use of Swepco 502 oil improver which helps quiet engines at engine start. Given the amount of oil both engines held I had to buy two bottles of the Swepco per engine. I used it and there was a reduction in noise but it was not that much. Mainly I was more concerned about providing a bit more protection against metal to metal contact at cold start. Oh, I had the Swepco stuff analyzed and it contains 200ppm of moly in some micro sized form.

bovien

More with 5w-50

RAudi Driver

Oil is thicker so slower to get to vital parts.

noro

yes.. that makes sense, the thicker oil takes longer to "pressurize" the tensioners and thus the chain rattles longer. Btw this can be counter intuitive because thicker oil generally shows more measured pressure on the cluster. This is because the the pressure is measured early in the supply chain and it's essentially indicative of the "force" the pump has to excert to push the oil throughout all the small passages.