So after many 0W40 Mobil 1 oil changes i am debating to change to 5W40. Car is ~57k miles now and last oil change showed some black plastic bits in the filter, probably from chain tensioner pads. I hear some rattle from what sounds like the timing chains on random cold starts. It was more frequent before I replaced the alternator/starter cable - starts were getting very slow even when the cable/starter was cold. The new cable seems to have helped somewhat regarding the chain rattle - not as loud / frequent.

My question is ... will going to 5W40 help or hurt getting the chain tensioners to pressurize faster?

Let me know your thoughts. I plan an oil change this month.

 

There are some oil brands that make a difference, but nothing on the Mobil 1 truck will probably do it.

If you are going to switch to 5w-40, consider Motul.

My tensioner pads were replaced at 63,000 miles and were badly worn on my 996. I still get some rattle/knock on cold start, and not sure what it is, but it goes away if I drive the car immediately within 5-10 seconds. If I let it idle to warm up, it can last 1-2 mins.

 

I drive year round and will probably stick with M1 for winter and go to Liqui Moly 5W40 for warm/hot months.

 

OP: have done looked at the cam deviations with a Durametric or equivalent tool?

When the tensioner pads wear, the tensioners have to expand further than usual, and since the tensioners on the M96 engine are one of the last legs in the oil pathway, it can take awhile for oil to get there fully.

 

Will look into the Durametric test with my indy tech. But just in case my 911 is a 2006 C2S with a M97 engine - daily driver in South Florida.

I am thinking of trying Motul 5W40 this time and see what happens\. I used that on my 987 Boxster for several years.

 

Thats right, you have an M97.

 

Make the easy peasy switch to Mobil 5W50.

If you drive at temps less than -13 degrees, use a 0W40 A40 approved flavor.

 

There are several brands used on this forum and many that still use Mobil 1 0W-40 and are happy with it. Motul 8100 Excess, Liquimoly Leichtauf HiTech and Total Quartz 9000 are all excellent oils and all the companies make race oil for LeMans, F1, F2, and other Euro autosports. All 3 come in 5W-40. You will have to make your own choices.

When I switched from 0W-40 Mobil 1 to Total 5W-40 (my indy's choice) my oil consumption decreased dramatically from 1300 miles per quart to 2800+ miles per quart. I'm sure it's the weight not the brand. The 0 weight is really thin and IMO was getting past the rings a little easier. I had my AOS checked and its fine. I may have a crack in a hose somewhere as Jake Raby from Flat 6 (I think it was Jake) said on one post, that he always finds cracked hoses on every car that comes to the shop. Apparently they don't age well.

All that said - Your use case if different. If you have an issue as you suspect, I wouldn't try to fix it with oil, I would just have it fixed properly by a mechanic. You shouldn't really take chances with these motors, they are breathtakingly expensive to fix is something major happens...

 

I just had mine changed in south florida and the guy down here uses 5-40 motul. It does seem to run a hair smoother than the expensive pennzoil or castorl speed sport tuning used. I think the only fear is heavier oil gets thicker in extreme cold and longer to get to temp.

 

Everyone has an opinion on oil. So in the spirit of that, here's my opinion...

Motul 8100 X-Cess 5w40

It has an A40 (Porsche approved) designation.

Since switching over from Mobil 1 0W40 to Motul, my car uses less oil between changes, and the engine creates far less soot. Plus the car just runs better with the Motul.

(I also add one 300ml bottle / can of LiquiMoly MOS2, and a dash of Eye of Newt...)

 

X2 on this Liquimoly Leichtauf HiTech + Ceratec or MOS2 ....Purrrrrring like a kitten ...

 

Driven DT40 5w40.

 

pbxtr!!, stop driving the car until you can have all 3 of your chain tensioners replaced. Bank 1 and the IMS one are fairly easy. To do bank 2, you have to remove the A/C compressor (3 bolts - not terrible but leave all the lines connected). To do this though, you'll need to pull the airbox and remove the serpentine belt - pretty easy as well.

The plastic bits you found are exactly that. Dark brown plastic is from one of the tensioner pads and black plastic from different ones. What's happening is the springs in your tensioners have become weak and when the car isn't running and the oil pressure bleeds out of them, the spring isn't holding the tension on the chain until the tensioner can repressurize. So, the chains are actually slapping against the tensioner pads and chipping the plastic away. That plastic is the only thing that keeps the chain from hitting the metal paddle underneath the pad - when that happens it's game over and you'll have chunks of metal tension paddle in the oiling system. Mike Murphy - this is the cause of the rattling noise you're hearing as well so you need to do the same - that's called the cold start "death rattle". The new tensioners will have fresh springs and no wear on the seals, so will hold the oil pressure longer so they'll pump up faster and the spring will hold the static pressure on the chain for the initial start better to prevent the slapping and eliminate that noise.

As far as changing oil. My recommendation would be Driven DT40 and it has properly high levels of Zinc, Phosphorous, and Moly where you don't need to add anything else to it. Coming from Mobil 1 where the base stock doesn't play well with that in the Driven oil, you'll need to do a flush between the changeover. Do a normal oil change and instead of going right to the DT40, use their Break In oil - either BR30 or BR40 for 100 miles, then change the oil and filter again and put in the DT40. You can get any of these oils from Summit Racing or LN Engineering. Motul xcess 8100 5W/40 is another good choice if you're worried about using an oil with A40 approval, but my personal UOA reports on 2 997.1 cars are the best with DT40 over the Motul or the Mobil 1 I had started with. I now use Driven lubricants in everything - transfer cases, differentials, engines, automatic transmissions, manual transmisison with LS, etc. The one exception is the MT in the 997 where Mobilube PTX is the absolute best fluid for our transmissions.

To change the tensioners, you need to lock the cams at TDC so you need a crankshaft pulley locking pin (a correct size drill bit will also work) and the cam lock tool. To access the cam end to lock them you'll need to pull 2 disposable plugs out so you will need new plugs to reinstall. You can get these from FCP Euro for a couple dollars each. Do one tensioner at a time - remove it, oil the new one and install that before moving onto the next one, so 2 tensioners stay installed in the motor at all times while both the crank pulley and the cams are locked by the tools.




Photo of Bank 2 Tensioner below A/C compressor and compressor mounting bracket

 

Pete, I assume all these can be changed with the engine in the car?

 

Yes, Bank 1 and the IMS one are pretty easily accessible. Bank 2 is the pain because of the AC Compressor and mounting bracket. My car has a different crank pulley because of the supercharger, so I was a little worried because there's no hole in my pulley to lock the pulley to the hole in the block. I rotated the motor, locked the Bank 1 cams and then used a clamp inside the crank pulley to hold it in that position and put a scribe mark at exactly 12 o'clock so I'd be able to tell if it moved at all during the replacement procedure. It didn't move and the engine didn't eat itself when I started it, and I have about 5 hours (1 at 90-100 MPH the entire time) on it since reassembly so assume I'm good





Clamp locking crank pulley to engine brace is visible in the background




These are the one time use cam end plugs that have to be removed to lock the cams in position using the cam lock tool. There are 2 per motor bank. Getting to the Bank 2 ones is harder, so I locked the bank 1 cam and the crank pulley and did all 3 tensioners that way - again 1 at a time.