gradyex

Thanks Kevin and Macster for the advice. I will try and purchase Mobil 1 5w-40 TDT or Mobil 1 5w-50. Kevin I never did pull the fuse to my fuel pump to prime it on start up after an oil change. I assume you crank the engine a few times and then re-connect the fuse. When I do start the car after changing my oil I just let it idle and the oil pressure builds up quickly. I know what you mean though it takes a few seconds for the oil pressure gauge to move up, its not instantaneous.

Macster

If you want to do the pull the fuel pump fuse thing then pull teh fuse and crank the engine a short time.

How long is a short time?

Well, hard to say. The starter motor is not designed for long periods of cranking so if it is used for any length of time it will get hot and heat ain't good for starter motors. Think about it next time you start your car's engine. How long does the starter actually crank before the engine fires and runs?

(When my Boxster's fuel pump quit in the hopes the engine would resume running (before I confirmed the fuel pump was the culprit) I'd crank the engine maybe at most 5 seconds before stopping and then I'd wait a few minutes before trying again. And I only did this a few times before giving up with the realization that the engine was not just going to fire and run.)

Thus my WAG would be somewhere between say 5 to 10 seconds, though even 10 seconds is a lot of time. I just turned around and watched my office clock's second hand sweep 10 seconds of time and that's a long time to run a starter.

Or during the cranking operation you could observe the oil pressure gage and stop when you see some oil pressure, provided of course the max. amount of time you decide to run the starter is not exceeded waiting for oil pressure to show.

But I guess the procedure is harmless enough a procedure (as long as one doesn't burn up the starter) to do it if one wants.

However, I have a couple of problems with this technique. I don't believe it is necessary to do this after a simple oil/filter change. None of the factory oil/filter service sections have this step. The Porsche techs I've talked to say it is not necessary. And the overwhelming majority of car owners and car repair shops do *not* do this after a simple oil/filter service and there doesn't seem to be any problems being reported. And we're talking every make and model of car. One hopes that Porsche is *not* the only car maker who can't build an engine that doesn't require this step after a simple oil/filter service. And then forgets to mention this important step in the owners manual, the factory manual, and even fails to inform the techs it trains to service these cars.

Second the starter only cranks the engine to at best (my info) 150 rpms. (Exact cranking speed hard to come by but my various encounters with this info is the starter spins the engine from 75 to 150 rpms. Is is not very fast, does not have to be very fast, cause as I covered above the engine starts within a very short time after the engine starts cranking over so the engine's not spinning very fast at all when it starts running.)

Anyhow, so at 10 seconds the engine makes around 25 revolutions. This is too brief a cranking time to push much oil all the way through the engine so the engine's bearing surfaces -- those the furthest away from the oil pump -- are essentially relying upon whatever residual oil is present for their lubrication during this cranking phase.

I have not been able to confirm this with my own eyes but the techs tell me the Turbo's oil pressure pickup for the in dash gage is located quite a distance away from the oil pump. (A tech did point out my Boxster's oil pressure sensor and it is located on the camshaft cover about as far away from the oil pump as it can get and still be connected to the engine.)

Thus the oil pressure sensor is a distance away from the oil pump -- it is at the end of the oil distribution circuit so to speak -- and while the oil pressure gage may be slow to show oil pressure oil is flowing and pressure is building from the get go. Gear oil pumps are like that. They move the oil. (At 5K rpms the oil pump can pump 60 or more liters of oil per minute.) The absence of 4 to 5 bar of oil pressure (cold) immediately after a cold engine start (or a warm start after an oil change) does not mean the engine is running sans any oil.

But as I said above, I guess the procedure is harmless enough a procedure (as long as one doesn't burn up the starter) to do it if one wants.

Sincerely,

Macster.

E55AMG

so, under what scenario would one run 5W-40 TD vs. 5W-50?

Macster

Fans of Mobil 1 TDT 5w-40 won't like my answer but the only scenario that makes sense to me is if one didn't like his Turbo's engine.

Offline I started a longish post on this subject, gathering the info I could to back up my statement above, but I probably won't have this all sorted out before I leave town later this week, but here are a couple of what I hope to of some value high points...

1) TDT oil is not on Porsche's approved oils list (the latest one I have is from the middle of last year), not even for its diesel Cayenne. Now understand Porsche on its approved oils list doesn't quote API-SAE engine oil service category classifications nor ILSAC specs or ECEA standards. (Porsche does of course use the SAE viscosity numbers.) An oil is listed and that's that. Oh, each oil on the list has a certification expiration date too. The approved oils are only approved for a few years at most. "Porsche AG has reached an agreement with the oil companies which involves setting a time limit on the validity of our engine oil approvals. The period of vailidity is between 2 and 3 years. Once this validity period has elapsed the approval in question is revoked unless an extension is requested by the relevant manufacturer."

2) On the Mobil oil web site TDT oil is recommended for: Diesel-powered pickup trucks built by Ford, GM, GMC and Dodge. Furthermore, it meets diesel engine requirements of Cummins, Powerstroke, Duramax and Navistar. No mention for use in a 996 Turbo. In fact no mention of using it in a gasoline engine at all.

Yet for other of its oils Mobil touts the oils' approval for use in various cars from VWs, BMW, Mercedes, and of course Porsches. One would think it this TDT oil were so good for Porsches Mobil would list Porches along with Ford and GM/GMC and Dodge pickups and 996 Turbo engines along with Cummins, Powerstroke, Duramax and Navistar.

3) Mobil 1 TDT 5W-40 oil is best I can tell is compromised of PAOs (good) and possibly esters (gooder). But esters have a tendency to swell seals. If one switches to this oil the good news is seeping seals might stop seeping. The bad news is if one stops using TDT oil the seals shrink and the engine leaks oil. Or if the seals were ok to begin with then switching back could have the seals leaking.

4) Since Mobil 1 TDT 5W-40 is *not* approved, if one wanted to use it anyway, according to Porsche the engine may need to be flushed first.

Here's what Porsche has to say on this: "All engine oils approved by Porsche can be mixed provided they are of the same Porsche oil specfication. This means it is not necessary to flush the engine when the oil is changed if another type of oil is used."

Porsche does recommend that the same oil be used to top up the engine's oil level if possible.

This implies to me that if one steps off the list and uses a non-approved oil, a different oil, one blended for a different type of engine (diesel vs. gasoline), the engine should be flushed first

(As an aside: Flushed with what I don't know. Maybe the Porsche approved oil is drained, and the filter replaced, then the engine filled with TDT oil and run a while to flush/intermingle with the approved oil then this combination of approved oil and TDT oil drained and the filter replaced and the engine then filled with TDT oil. Porsche is under no obligation to provide any help in this area. It has provided an approved oils list. If one strays from the list, he's on his own.)

Scott Slausen (porschedocotor@aol.com) in March's PCA Porsche Panorama Tech Q&A has this to say when asked about an oil recommendation (for a 2001 Boxster S): Mobil 1 0w-40 or 5w-40. The oils with higher ZDDP levels are not recommended as they are a mix of standard and synthetic. They also tend to have higher viscosities. The standard part of the oil gives a slightly higher ZDDP level yet the synthetic is blended to try and give it a longer life. While ZDDP was first introduced in the '50s for camshaft to flat tappet design [sic] it has been surpassed in general by synthetic oils. A standard oil will break down in as little as 700 miles which was one reason oils had been changed every 3000 miles or less. Synthetic oils show no significant break downs for at least 7000 miles.

It just so happens in May's issue of Excellence Bruce Anderson in Tech Notes also covers Porsche oil selection. He recommends Motul 8100 X-MAX or one of the other Group V synthetic oils. I was not able to find much info on this oil other than it is a "high performance 100% synthetic lubricant" and it is Porsche A40 approved. BTW, the Porsche A40 standard requires extreme high shear resistance from the lubricant. One benefit from Motul is it is made of Group V esters and (according to Bruce) esters handle heat better than PAO based oils. When burned esters leave far less coking deposists; this is particularly useful in turbo-charged engines -- where the heat in the turbo tends to cause coking with conventional oils.

Is TDT a mix/blend of synthetic and standard oils? Can't say. I found the chemical make up to contain at least 20 to 30% PAO (1-Decene, tetramer and trimer hydrogenated) with Zinc dithiophosate (ZDDP) (< 2.5%).

That first mouthfull even has its own CAS #: (68649-12-7); and this is simply: Synthetic hydrocarbon base oil.

Here is a list of the ingredients in Mobil 1 TDT 5w-40 oil:

Name Concentration
Trade Secret 01 40-50%
Trade Secret 02 20-30% (this might the PAO stock from above.)
Trade Secret 03 10-20%
Trade Secret 04 5-10%
Trade Secret 05 5-10%
Trade Secret 06 1-5% (this might be the Zinc dithiophosphate)
Trade Secret 07 0.1-1%
Trade Secret 08 0.1-1%

So given the above, is TDT a mix/blend of synthetic and standard oils? You decide.

How about Mobil 1 0w-40: Synthetic base stocks and additives. That's it.

I did find a bit on info on Castrol Syntec 5w-40 oil (its on the approved list). Its composition/ingredients: Synthetic base stock. Proprietary performance additives. Ingredient name: Base oil -- highly refined - CAS # (varies), and percent 90-95%. This oil appears to have a more homogenous composition than that TDT oil.

How about Mobil 1 5w-40? Now this gets fuzzy. There are several 5w-40 oils on the approved oils list: Esso Ultron, Synt S 5w-40, Syst S 5w-40, just plain old 5w-40 (this the only one with USA after it), another plain unadorned 5w-40 (but I note this oil is no longer valid its approval having expired 17.10.2010), Super 3000 X2, and Formula X2. All of the above oils (save the one I mentioned) have 'WW' for their region. 'WW' is world wide, which of course includes USA.

Its composition/ingredients? Synthetic base stocks and additives. In more detail? 1-decene, homopolymer hydrogenated (CAS #: 68037-01-4). Concentration: 10-20%.

Next up is: 1-DECENE, TETRAMER AND TRIMER HYDROGENATED (CAS # 68649-12-7) in a concentration of 20 - 30%.

Followed by: POLYOLEFIN POLYAMINE SUCCINIMIDE (CAS #:147880-09-9) and in a concentration of 1 - 5%.

Then there is: Mineral Oil (no CAS #) and concentration: 30-40%.

Regarding Mobil 1 5w-40 oil: I admit I have been running Mobil 1 5w-40 oil -- though I don't have the bottle in my hand to note exactly which oil I picked up from the oil distributor a while back -- in my Turbo these last 4K miles. The Turbo's going in for an oil change later this week before I take it out on the road. At this time I honestly do not know what oil I'll put in the Turbo's engine. Frankly I'm fed up with thinking about oils.

Anyhow, I haven't yet found anything on Mobil 1 5w-50 (or 15w-50 either).

Now, before all the flames begin (and in which I probably won't participate in since I'm sick of oil discussions and I'm rushing around trying to get things done so I can take a much needed vacation), one is of course free to use whatever oil he wants, though at least for a car still under warranty I would advise one stick to one of the oils on Porsche's approved oils list.

After that, use whatever you want. To give my Turbo a good chance of lasting a long time I'd at least try to use an oil designed for a turbo-changed *gas* engine and probably a Group V oil (ester based) since as Bruce noted this leaves less residue when burned. (In fact if I can find such an oil before I take the Turbo in for its oil change I might just switch to such an oil.)

It occurs to me that owners of the newer Porsches with the DFI engine might do well to consider using an ester based (Group V) oil to lessen the buildup of engine deposits from the oil.

But there is still the seal swelling issue. But using an approved oil, a Group V oil, there should be no reason to ever switch back (down?) to PAO (Group IV) oil thus there will be no reduction in the esters content and seal shrinkage should not be a problem.

Sincerely,

Macster.

Kevin

Macster I have recently spoke with Mobil, they have assured me that 5W40 TDT is 100% fully synthetic oil. Do I feel that it's better than a double ester oil >No.. when compared to Motul's double ester oil. However, the formulation in ALL gasoline engines have changed in the last 24 months.

If you own a 996TT or 997TT that is out of warranty OR a car that you are going to keep for a long time, I would be running either the 5W50 or the 5W40 IF you are hearing a louder IMS and valvetrain noise. I'll take the metal conditioners in the 5W40 TDT over the additives in the 5W50. The seal and oring swelling has not been an issue with this engine. The EGT in the newer diesel engines are running similar to our VNT's.

In the end, one should make the switch over to a 5W oil.

dianic

Kevin i think you havent read the post of Macaster. Perhaps read it again...
You spoke with Mobil and they assured you its 100% synthetic? Can I see that in writing? If Macaster is taking the time to document his posts shouldnt you be doing the same? If 5w-40 has 30% mineral oil, why does the TDT not?
My favorite Boston Legal comes to mind: Speaking to Mobil is hear-say. Who did you speak with? What is their position? Can they give it to you in writing?

I do appreciate your input in this and other threads, dont get me wrong, but you still need to back up your recommendations.

I am not trying to flame or anything, as I said I appreciate your input. This is just my recommendation, on a personal level. Take it with a pinch of salt, or toss it... its up to you...

Kevin

Dianic, you can believe what you want to.. Macster can cut and paste all of his replies.

For instance. He quotes Slausen ZDDP reply. It's BS in my book. These engines are having issues since the additive packs have been changed. These engines NEED the zinc and other metal conditioners. I have seen the component failures. When people PM and email me about the metal fragments in there oil filter >> you ask why these engines are shedding the metal. Don't kid yourself, the 997TT engines shares 99% of the same components as the 996TT "internally".

You can go to the Mobil 1 website and compare each oil. The TDT per Mobil's site reads:

Is Mobil 1 with SuperSyn Technology a fully synthetic motor oil?

Yes, it is. To meet the demanding requirements of today's specifications (and our customers' expectations), Mobil 1 with SuperSyn uses high-performance fluids, including polyalphaolefins (PAOs), along with a proprietary system of additives. Each Mobil 1 with SuperSyn viscosity grade uses a unique combination of synthetic fluids and selected additives in order to tailor the viscosity grade to its specific application.

It is NOT a synthetic BLENDED oil.

Kevin

Here is a recent TESTING trial. Oil samples reported by Blackstone.

You can see OW40 and 5W40TDT in action. From right to left shows the recent mileage oil sample.

Oil Filter--------M1-109
OIL __________ D1ESP5w40 D1ESP5w40 M1TDT5w40 M1 0w40 M1 0w40 M1 0w40
MILES IN USE ------ 15,077 ___ 10,279 ___ 9800 ___ 9986 ___ 5000 ___ 9437
MI/HR-ON-UNIT----- 106,356 101,279 91800 69627 59641 54641

ALUMINUM---------- 5 4 4 (3) 4
CHROMIUM---------- 1 1 1 1 (1) 1
IRON-------------- 20 16 26 38 (10) 15
COPPER------------ 5 3 5 3 (3) 3
LEAD-------------- 14 7 7 15 (6) 25
TIN--------------- 0 4 1 5 (0) 0
MOLYBDENUM-------- 6 5 19 75 (74) 87
NICKEL------------ 0 0 0 0 (0) 0
MANGANESE--------- 2 2 1 1 (0) 0
SILVER------------ 0 0 0 0 (0) 0
TITANIUM---------- 0 0 0 0 (0) 0
POTASSIUM--------- 3 3 3 3 (3) 0
BORON------------- 33 33 38 115 (124) 127
SILICON----------- 15 10 11 13 (11) 10
SODIUM------------ 7 6 5 7 (8) 10
CALCIUM----------- 1655 1436 1702 2847 (2551) 2941
MAGNESIUM--------- 1004 819 665 15 (13) 17
PHOSPHORUS-------- 1124 1011 913 823 (728) 813
ZINC-------------- 1739 1434 1150 1016 (895) 1034
BARIUM------------ 0 0 0 0

SUS-VIS@210F------ 82.6 78.2 76.9 71.3 (70.9) 70.9
cSt-VIS@100c------ 16.16 15.06 14.75 13.29 (13.19) 13.19
FLASHPOINT-IN-F--- 415 410 410 390 (420) 395
FUEL%-------------<0.5
ANTIFREEZE%-------0.0
WATER%------------0.0
INSOLUBLES%------- 0.2 0.2 0.3 0.3 (0.3) 0.4
TBN--------------- 1.2 2.5 3.0 3.9 (6.0) 2.4

Kevin

Can you folks see the higher IRON when you stretch out the M1 0W40 to a 10K service??

Look at the METAL CONDITIONERS >> Zinc and Phosporus with the Delvac Diesel and TDT.

You can also see the Moly in the 0W40.

The higher weights show a higher Viscous 100 degree mark.

gradyex

I did the oil change over to Mobil 1 5w-40 TDT and it did quiet the noise a bit. I checked my oil filter (cut in half) and couldn't see any obvious metal fragments. As long as it doesn't get much worse I am not that concerned.

Would be great if others with the same type of problem could chime in and tell us when it started, if it got worse, if you did anything about it, and how many miles you currently have on the car. I don't need to hear the usual comments like "just crank up the radio" or "get an aftermarket exhaust". It may not be a big deal to some but I love the sound of my Gt1 engine (sounds like the air cooled engines of the past) and I plan to keep this automobile for many years to come.

gradyex

Macster, I didn't read your post until after I changed my oil to Mobil 5w-40 TDT. I am not worried about the oil itself but the effect it might have on my cars warranty. I'll switch back to Mobil 5w-50 or straight 5w-40? Which oil would you guys (Kevin or Macster) switch over to keeping in mind that it must be on Porsches approval list? I do still have 2 weeks left on my factory warranty but afterwards my 3 year 36k mi bumper to bumper extended warranty kicks in. I should of checked first but switching it out is not a big deal to me. It usually takes me less than 1/2 hour to do the oil and filter on my car anyway. I won't go back to 0w - 40 its just too thin and the noise was more pronounced when I used it.

gradyex

How do you folks feel about using Motul 8100 X-clean 5w-40? I understand that it is a porsche approved oil product that is 100% synthetic? Seems that this is a popular type of oil used in these cars?

E55AMG

Was looking at this also. Would like to hear others' opinion.

jhbrennan

Is the 8100 a Group V product or is it only the 300v that is? If not Group V, why is the 8100 5w-40 any different than M1 5w-40? Thanks.

Kevin

Gradyex, I would keep the 5W40 TDT since you have engine noise. Switching to Mobil 5W50 will not dampen the noise. I do NOT have customer supplied oil samples for any good trends for the 997TT platform. The only real change with this engine is the 2nd piston cooling nozzle that has been added to cool the underside and piston pin/rod bushing.

If you folks have 20K miles and above AND plan on keeping your cars ( I think that the gen 1 997TT and GT is that LAST of this great engine), establishing a oil wear baseline will provide value to your car and peace of mind.

Motul 300V is the group V oil. If one was going to change there oil every 3K miles, I would recommend the 300V. I stand by my convictions, 5W40 TDT is the oil of choice for those with engine noise. If you are getting near your warranty period, I would make the change. I would also get in the habit of removing your oil filter element at 2500 miles. Open the pleats and examine the filter for metal. Go over to the 996TT forum and read the engine failures. My soapbox stance, is from the removal and change of the metal conditioners and additive packs. Diesel/offroad and motorcycle oils are exempt from the EPA guidelines. While some may say that the new additives "work", the question is "how well" do they work, and do they work well for your Chevy pickup. We are seeing a accelerated wear pattern on the 996TT and GT3's.