Reading Cam Deviation Values

[blue62]

Originally Posted by PLP

Actually, I would like to know what to exactly measure and how to measure.

I will be renting Durametric Pro again (to finally activate cruise control) and I could run all the checks.

It would be nice if someone took the time to explain this stuff and show which exactly screens/variables should be active/measured.

As far as checking Camshaft Deviation it is simple:
Take the car for a good spirited 20-30 minute drive.
You want the engine oil good and warmed up and at a stable temp.
Hook up the Durametric and go to the actual values tab.
Click on... Camshaft deviation Bank-1
Click on Camshaft deviation Bank-2
Should bring up a graph and also number on the right hand side.
Do this at idle RPM.

Do a search here on the forum for camshaft deviation you will find plenty of screen shots.

If you have any problems figuring it out let me know.

Just noticed that you have a 2003 so I think your Vario Cam system is different. If it is the Vario Cam plus system then that system functions in a different way. So I do not know if Camshaft Deviation applys to that system. Perhaps someone here on the forum knows.

[TTGator]

Originally Posted by blue62

As far as checking Camshaft Deviation it is simple:
Take the car for a good spirited 20-30 minute drive.
You want the engine oil good and warmed up and at a stable temp.
Hook up the Durametric and go to the actual values tab.
Click on... Camshaft deviation Bank-1
Click on Camshaft deviation Bank-2
Should bring up a graph and also number on the right hand side.
Do this at idle RPM.

Do a search here on the forum for camshaft deviation you will find plenty of screen shots.

If you have any problems figuring it out let me know.

Just noticed that you have a 2003 so I think your Vario Cam system is different. If it is the Vario Cam plus system then that system functions in a different way. So I do not know if Camshaft Deviation applys to that system. Perhaps someone here on the forum knows.

Or watch the video

Only inconsistency I see is I was told to do this from a cold engine and you are saying warm.

[blue62]

Originally Posted by TTGator

Or watch the video

Only inconsistency I see is I was told to do this from a cold engine and you are saying warm.

Yes well warmed or operating temp.
Very few tests of a system under operation are done (correctly) at other then operating temp.

........To many inconsistencies......

It is not only the temp of all the different types of metals involved.....bearings, valves, lifters, springs, cams, chains, sprockets, etc..etc..
Tolerances change with temp. (expansion, contraction).
But also and perhaps more importantly is oil operating temp. (around 175+ degrees F. I think).
These engines have a large oil capacity so it takes some time to get all that oil up to temp.
The Vario Cam system is operated by oil pressure as are the lifters, so you want that oil temp. (Thus oil pressure) to be as consistent and as close to operational specs. (pressure) as possible.

In "most cases" when doing any kind of operational or diagnostic testing on a system you want that system as close to manufactures specs. and operational conditions as possible.

Think about it... you don't operate the engine cold for anymore then the time it takes to warm it up. On say an hour long drive your at cold state for just a minute or two. The rest of the time temp. is increasing or has reached operating temp for the conditions.
Doesn't really make sense to test it cold.

Hope this makes sense.