[jmckeefery]

While I was resetting my timing belt to correct the cam timing, (see "persistent engine knock"), I noticed that the Vario Cam chain has been rubbing the valve cover. I have been able to hear this when I start the car for years, but could not find the cause. When the oil pressure is low, the chain rubs the valve cover and sounds like a chain rattling. As soon as the oil pressure goes above 30% on the gauge, the noise stops. If I pull the coil wire and crank the motor 30 seconds to get oil pressure and then reconnect the coil wire and start the car, the chain rattle is not heard. So at engine cranking RPM the chain does not rub, only at idle RPM and above and low oil pressure.



Anyone know of a cure for this?



James McKeefery

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[Spieln968]

James,



I would verify that the check valve is in place. If you remove the J tube, you will find it in the top of the variocam. Be careful as it will easily pop out if you push on the variocam cylinder.



How is your oil pressure at idle? Another potential problem could be a cracked oil pick up tube. I think someone here or on another site had a problem with a noisy variocam and the problem was a cracked pickup tube. This is caused by the balance shafts being out of phase. You might try searching for this on the three sites.



Good luck,

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[jmckeefery]

[quote name='Spieln968' date='May 16 2006, 07:45 AM']James,



I would verify that the check valve is in place.  If you remove the J tube, you will find it in the top of the variocam.  Be careful as it will easily pop out if you push on the variocam cylinder.

Good luck,

[right][post="21070"]<{POST_SNAPBACK}>[/post][/right][/quote]



Where can I find a replacement part for this? The oil pressure at idle is great, max on the oil pressure gauge. I assume that I remove the "J" tube and then pop the check valve out and replace it. Is there anything more tricky than that? Are there gaskets that I will need to replace?



I have the full shop manual for the 968. The only reference to this check valve is attached below. It may be in the 944 manual which I thought would have been included in my manual set, but was not.



I have checked Pelican Parts and can not find any reference to it.



Thanks for your help.

James

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[mitch968]

[quote name='jmckeefery' date='May 16 2006, 03:53 PM']The oil pressure at idle is great, max on the oil pressure gauge.[/quote]

I presume you mean the pressure is high at idle when cold? Once the oil is up to temp it should drop down to between 2 and 3 on the gauge when idling and rise higher when revved. If your gauge is pegged all the time, I would think there may be a problem with the sender.

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[Spieln968]

The 944 does not have a variocam so there would not be a reference to it in the 944 manual. You will need new crush washers for the j-tube and possibly a new o-ring for the check valve. I will look and see if I can come up with a part number. I did a little research on this and there is a case where one person had a broken spring in the check valve and they had the same problem that you have.



BTW, you will see the check valve as soon as you remove the j-tube in case you were wondering where it is.

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[Spieln968]

I believe the part number is 944-105-508-00. Has a price of $112 on the Pelican site. Seems like a lot of money for what it is. Welcome to the world of Porsche.



I would look at it first before I ordered it. I think it will be obvious if the spring inside it is broken.



Hopefully you will find this to be your problem as a cracked oil pickup would be a real mess to fix.

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[jmckeefery]

[quote name='mitch968' date='May 16 2006, 01:04 PM']I presume you mean the pressure is high at idle when cold?  Once the oil is up to temp it should drop down to between 2 and 3 on the gauge when idling and rise higher when revved.  If your gauge is pegged all the time, I would think there may be a problem with the sender.

[right][post="21096"]<{POST_SNAPBACK}>[/post][/right][/quote]



The oil pressure is as you describe it. High at cold idle. So the Vario Cam has oil pressure to work with. The broken spring sounds like the most plausible cause so far.



James

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[jmckeefery]

[quote name='Spieln968' date='May 16 2006, 01:50 PM']I believe the part number is 944-105-508-00.  Has a price of $112 on the Pelican site.  Seems like a lot of money for what it is.  Welcome to the world of Porsche.



I would look at it first before I ordered it.  I think it will be obvious if the spring inside it is broken.



Hopefully you will find this to be your problem as a cracked oil pickup would be a real mess to fix.

[right][post="21099"]<{POST_SNAPBACK}>[/post][/right][/quote]





Thanks for your research on this. The cost of Porsche parts does not bother me. I accepted $300 water pumps when I bought the car. I am an engineer, and because the car is so well designed and finished, it is the only car I have owned that I actually enjoy working on.



I see from the Pelican site that this part is a special-order, non-returnable, part. I am inclined to get it anyway if you are sure it is the right part.



Thanks,

James

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[Spieln968]

[quote name='jmckeefery' date='May 17 2006, 07:52 PM']Thanks for your research on this.  The cost of Porsche parts does not bother me.  I accepted $300 water pumps when I bought the car.  I am an engineer, and because the car is so well designed and finished, it is the only car I have owned that I actually enjoy working on. 



I see from the Pelican site that this part is a special-order, non-returnable, part.  I am inclined to get it anyway if you are sure it is the right part.



Thanks,

James

[right][post="21183"]<{POST_SNAPBACK}>[/post][/right][/quote]



I have never ordered the part so I am not 100% sure of the part number. I found it by doing a search on another site.



If it were me, I would call Sunset Porsche, verify the part number and order it from them. I have found that they are a little cheaper on special order Porsche parts.

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[Charles Geer]

[quote name='Spieln968' date='May 18 2006, 06:41 AM']I have never ordered the part so I am not 100% sure of the part number.  I found it by doing a search on another site. 



If it were me, I would call Sunset Porsche, verify the part number and order it from them.  I have found that they are a little cheaper on special order Porsche parts.

[right][post="21223"]<{POST_SNAPBACK}>[/post][/right][/quote]



Go to the "racing" icon on this site and read "Harmonic Balancer" and "Oil Pick Up Tube".

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[jmckeefery]

[quote name='Spieln968' date='May 16 2006, 01:50 PM']

"I believe the part number is 944-105-508-00."



Thanks for the tip. I ordered the Vario Cam check valve from Sunset imports for $77.50 and the "O" ring and new crush washer were only $ .74 together.



I was quite surprised when I got the "J" tube off that the check valve was not even there! So that was definitely the problem. It must have been removed by a previous owner. I replaced the "O" ring and installed the new check valve and everything is fine.



James

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[bob blackwell]

Great! All well and good again, is this a wonderful site, or what? Good luck, Bob Blackwell.

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[gbarrier]

Very good find. And yes it is a great forum. I did the cam replacement a couple of weeks back and woke up in the middle of the night to the revelatiuon that I saw the checkvalve when I removed the Variocam assembly and didn't remember it when I put it back. Without a P/N I panicked at having to buy a whole assembly. After much searching on the shop floor and getting ready to dump the oil I found it perched under the exhaust cam on top of the head. Keep that P/N for future reference. I could not find it on PET.

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[gbarrier]

by the way (probably jumping threads a little) here's what happens when the variocam stuff is not checked periodically. This engine had a slight rattle when the rpms passed 2K on the way up. Valvecover looked just like the one at the first of this thread. It was heard only with the hood up. I bought the car with 100K on it and most other stuff maintained. After about 1K of driving it like I stole it I decided to pull the valve cover and take a look. Wow.

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