[Porsche Steve]

Nope... no smoke under normal driving... a bit of smoke early in the morning at start up though. I keep hoping that it's something simply since there's only 66k on the engine but with my level of oil consumption, probably not.

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[PorscheG96]

Quick update on this. Took the 968 to a shop that ran compression and leakdown tests on my engine but everything came back normally. Engine has consistent high compression and no signs of leakage through head or crank case. The problem with bad valve seals, guides, or piston oil rings is that I don't think they'll show up in a compression or leakdown test. However, we did decide to switch from Swepco 10w40 synthetic oil to Motul 10w40 synthetic and my 968 went through its first quart in 550 miles compared with 250-300 with the Swepco. This was after not being driven for the entire month of January. I realize that this is just a hack but there's really nothing else that I can do except pull the head and look around which I might do this coming summer unless the problem becomes worse. I'm also doing a track day here in the next couple weeks and hoping to seal up some oil rings if indeed that's the problem. Will obviously keep a close eye on oil consumption in the track environment, which I expect to be a bit higher than normal.

Steve, do you have any obvious oil leaks or do you ever smell oil burning off your exhaust? I do have some kind of external oil burning leak that I smell, especially after quick full throttle runs, but I didn't see where it was coming from when I was underneath my 968 recently.

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[cosimo]

I used a 1/2qt every 600 to 800 miles. I drive it almost everyday. I switched to Motul and now it is over 1000 miles before I have add. It is pricey but we (IMA motorsport) uses it exclusively for all oil changes. We have sent out oil from customer cars for analysis after 4500 miles and the results show it is as good as the original. The need for Motul arose because of the IMS failures on Boxster and 996 engines and was recommended by the L&N engineering after replacement of the IMS bearing. It is by far the best oil I have ever used.

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[ds968]

is Motul available at the usual autoparts chains ?

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[PorscheG96]

Dan, I'm about to order a spare gallon, want me to get you a couple as well?

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[ds968]

yes, thanks . might as well give it a try. Amsoil is great, but I'm always willing to try something that others have already tested with good results

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[cosimo]

Don't know if it avaliable at auto parts chains. We get it a the shop from a couple of local suppliers. Maybe try the web site to see if they have any places.

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[cosimo]

I just checked there web site and it will give you places to buy their oil.

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[Langley968]

Interesting statements about Motul...

I just checked on the web who sells it in my "neck of the woods" and the Motul site is very helpful. It seems to be mostly at european specialty shops. That in itself makes a strong statement for the product. I may give it a try next time.

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[DaveN]

That's all my mechanic uses, Motul engine and gear oil. He has to get it sent in though as he can't get it locally.

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[911rcr]

[quote name='PorscheG96' timestamp='1325114873' post='119713']

1 qt oil consumption every 300 miles isn't normal <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />

[/quote]

Hi PorscheG96,



I just purchased Porsche Steves 968 last month (with complete disclosure of the oil consumption issue). Just curious if you pulled the cylinder head yet and what you found?



Thanks!

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[PorscheG96]

You got a great deal on that car based on what I saw. Congrats. I'm fairly committed to pulling the cylinder head next month because the oil consumption remains a problem, though it doesn't appear to be getting any worse. I'm still using Motul 20w50 every 5k miles and engine consumes 1 quarter in 3-500 miles depending on whether I autocross or not. Question for you...have you experienced noisy lifters at any point? I get them after a few autocross runs and wonder if it's another symptom of the problem...



Ah, nearly forgot...Arash and I set the cam timing on my engine and in doing so noticed several clues that the cylinder head had been off my 968 before. The overwhelming evidence was a transfer of silver spray paint from the cylinder head to non-original valve cover gasket resulting in some oil seepage onto the headers. This points to either a broken timing belt or overheated/warped head at some point in the car's lifetime which I intend to fix correctly very soon. I hope whoever the guy was that thought spray painting the cylinder head was a good idea also slapped new seals or guides on incorrectly and buggered the head. <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />

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[flash]

bummer - while spray painting the head is a good idea, screwing the pooch on the job sucks.



if you're getting noisy lifters, it sounds like you have a bleed-off problem. what is the pressure when this happens.



have you looked at your air/oil separator? the internal diameter of the vacuum line on that is very critical. you cannot use vacuum hose, and must use the hard black plastic line. otherwise too much is drawn up from the separator and thrown right into the intake manifold.



also, it is very important that your oil cap is sealing fully. if there is a leak there, it will create a crankcase pressurization problem that will also dump oil into places it should not go.



it's funny how you find things when you tear things apart. we found a very disturbing flaw in the cam timing procedure, that can result in the cam timing being impossible to set correctly, and leave the relative timing off by as much as 13 degrees. it's not something anybody would think about, and everyone we spoke to about it had no idea it could happen. i haven't figure out how i want to handle a write up on it yet, but will soon.

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[911rcr]

[quote name='PorscheG96' timestamp='1349804562' post='133580']

You got a great deal on that car based on what I saw. Congrats. I'm fairly committed to pulling the cylinder head next month because the oil consumption remains a problem, though it doesn't appear to be getting any worse. I'm still using Motul 20w50 every 5k miles and engine consumes 1 quarter in 3-500 miles depending on whether I autocross or not. Question for you...have you experienced noisy lifters at any point? I get them after a few autocross runs and wonder if it's another symptom of the problem...



Ah, nearly forgot...Arash and I set the cam timing on my engine and in doing so noticed several clues that the cylinder head had been off my 968 before. The overwhelming evidence was a transfer of silver spray paint from the cylinder head to non-original valve cover gasket resulting in some oil seepage onto the headers. This points to either a broken timing belt or overheated/warped head at some point in the car's lifetime which I intend to fix correctly very soon. I hope whoever the guy was that thought spray painting the cylinder head was a good idea also slapped new seals or guides on incorrectly and buggered the head. <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />

[/quote]

No noisy lifters, in fact the engine is very quiet and tight other than cold timing belt whine at start up.



Flash, I have been suspect of the OAS but have not checked the intake for residue yet. Anxious to see your write up on correct valve timing procedure.



Thanks!

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[flash]

as i said, i'm not sure how to handle it, as it likely means having to have some things that most people don't, which means they would skip it. i suppose that would be no different than doing it by the book, and it coming out wrong.



i'll figure something out to explain the issue, and the resolution as soon as i can.



back on topic. my car still sits weeks at a time, but now loses absolutely no oil.

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[Cloud9...68]

I know this is getting off topic, but wouldn't the most effective (though not necessarily the easiest or fastest) way to set the valve timing be to get a G-Tech meter, and accelerate through the gears on a deserted road in calm weather conditions, move the timing, and repeat until you have the most power in the rpm range you care most about? Doing this on a dyno would be even better, but I know dyno time gets expensive quick.

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[flash]

not really. cam timing is a tricky thing. it needs to be done with the engine static

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[Eric_Oz_S2]

Has anyone ever tested changing the cam timing +/- 4 degrees using the slotted adjuster on the "pulley"? Interesting that on the 944NA, advancing the cam timing 4 degrees made more power. On a supercharged engine it may even have more of an effect.

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[flash]

yup - pick what you want, low end torque, or upper end horsepower. where you put it determines what you get.

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[PorscheG96]

Haha, just noticed that this thread has been going for a year - how time flies when having fun!!



Arash and I have most likely tracked down the cause of nasty oil consumption and it's a strange story. The cylinder head on my 968 has clearly been off before [guessing for blown timing belt] - the following signs were evident:



-bead blasted head surface

-spray paint transferred to valve cover gasket resulting in leak

-missing engine hoist bracket at rear of cylinder head

-poorly-timed cams

-Victory Reinz head gasket in fairly new condition

-and last but not least...A STRIPPED HEADER BOLT THREAD HELD IN WITH SILICON



The good news is that bores look like glass with absolutely no flaws evident. The bad news is that it looks like head was rebuilt very poorly, possibly with new valves and old guides - there's play in all the exhaust valves and raw oil just streaming from each of the exhaust ports. Not even combusted oil - just raw oil squirting out onto the header where the stripped exhaust hole is! So - hoping that the problem is totally fixed by this head rebuild which is at a top-notch Porsche machine shop in silicon valley. <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />

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