View Single Post
Old 05-18-2021, 07:18 AM   #28
bg305
01 Seal Gray 986 S
 
bg305's Avatar
 
Join Date: Sep 2019
Posts: 167
Quote:
Originally Posted by blue62 View Post
Ok I think I have it figured out.
First I was wrong on a point or two
Camshaft deviation and Camshaft angle readings are unrelated.
Cam deviation is expressed in degrees of crank rotation.
Actual cam angle is also expressed in degrees of crankshaft rotation.

Actual cam angle is what the DME expects to see.

So with Variocam actuator off the DME expects to see O degrees of Cam angle
With Variocam actuators on the DME expects to see 25 Degrees of Cam angle
That explains why you see both your cams at or very near 0 degrees at 700 RPM
And very near 25 degrees at the trigger point.

So Cam deviation is an adaptation value.

Where as Cam angle is degrees of Cam advance (exhaust cam only I think) when the Variocam system is active.
Seems that the "Actual cam angle" readings are related to the operation of the Variocam system only.

Thats my current understanding.
Sorry about any confusion from my previous post.
No worries! Thank you for weighing in, it was really helpful! I am trying to understand it as best I can as well.

I called around to local shops, found one that is taking it in next Wednesday. Described the issue and the mechanic said he would scope it and we would go from there. Assuming it is the guides I am going to ask them to check to see if the ims is single / dual row and possibly do that if it is single, clutch as well.

I will update with a resolution when I have one..
bg305 is offline   Reply With Quote