Camshaft Deviation Values...when to act

[schwartzki]

Good afternoon all,

 

1yr into ownership of my 2000 Boxster S manual 87k miles. Have short rattle during startup. IMS was done. Finally got around to reading my camshaft deviation values after a good drive.

 

Bank 1 is -5.23

Bank 2 is -4.25

 

Values are steady at idle and 3k rpm. Cam phases are working correctly. No CEL. My idle has some variability to it but no misfire counts. Have not replaced hydraulic tensioners yet. Running 5W40 oil. My understanding is the up to 6 is considered "normal" and don't need replacement till they get to 6.

 

My question is do I need to do the Cam chain guides and other chain tensioners this year or if they can go another season?

 

Trying to keep my annual servicing budget a tad reasonable and already have another big list this year.

Edited March 6, 2022 by schwartzki

[JFP in PA]

10 minutes ago, schwartzki said:

Trying to keep my annual servicing budget a tad reasonable and already have another big list this year.

Welcome to RennTech 

Life isn't going to be that simple; the spec limits on cam deviation values is +/- 6, and at 5.23 you are getting close.  Replacing the hydraulic tensioners is not going to help this problem; five chain engines are famous for having cam deviation issues caused by the small chain wear pads located in between the cams on the cylinder heads:

 

 

Cost wise, the pads are not expensive, but getting at them is labor intensive, and one of the reason Porsche switched to a three-chain cam drive, which does not use them.

[schwartzki]

That was the answer I was expecting but hoping not to hear JFP.

 

This would be a motor in replacement:

I have searched but cannot find a list of parts involved for doing the pad replacement, o-rings, gaskets, single use bolts, spark plug tube replacements, etc. Which timing lock tool is needed for motor in work?

 

Thanks

[JFP in PA]

Along with all the parts, you will need the cam retention tool to hold the cams in place while doing the work:

 

 

Or some homemade version:

 

 

 

 

[JFP in PA]

49 minutes ago, schwartzki said:

This would be a motor in replacement

 

And just an observation: This is one Hell of a lot easier with the engine out; actually saves time and allows you to do a better job with the engine on a stand; plus you can complete any other work at the same time.

[headdead]

The tool in the upper left holds the cams prior to removing the cam cover.

The tool in the upper right holds the cams after the cover is off, allowing them to turn and be timed, i think.

What does the tool in the lower center do?  Is it used for both 5 and 3 chain M96 engines?

 

[JFP in PA]

1 hour ago, headdead said:

The tool in the upper left holds the cams prior to removing the cam cover.

The tool in the upper right holds the cams after the cover is off, allowing them to turn and be timed, i think.

What does the tool in the lower center do?  Is it used for both 5 and 3 chain M96 engines?

 

 

If you are referring to the one with the knurled shaft, it is used to move the cam during reallocation.  The upper right image are designed to hold the cams in place after the cover is removed, but can also be used during reallocation. 

[headdead]

JPF

Thanks.  Am I correct in thinking I will be able to time the cams without the knurled shaft tool since I will time them with the cover off after I replace the chain guides?  Several threads seem to ignore this tool...

[JFP in PA]

Yes, you will be able to time without this tool; the tool just makes the process very slick.  Porsche engineering sometimes shows up more in their service tools......