If you want to find out why a W3WP worker process is consuming so much CPU, you can use ProcDump.  You might also use LogParser to look at the time-taken field, but to get to the root cause you will need to get deep into the source.  Before you can get a memory dump, you need the PID of the worker process.  You can get the PID in a number of ways.  Below I illustrate using either PowerShell or AppCmd, for example.

Here is a previous article I wrote that covers how to get the PID of a worker process in PowerShell.  Figure 1 illustrated the specific PowerShell command.

Figure 1, finding the W3WP PID using PowerShell

You can also find the PID using AppCmd, as shown in Figure 2.  I wrote a more detailed article about how to do this here.

Figure 2, finding the W3WP PID using AppCmd

When you have found the PID (Process ID), you can use it as a parameter of the ProcDump command.  Enter this ProcDump command, shown in Figure 3, to capture a 64-bit full memory dump when the CPU consumption is greater than 90% for 5 seconds:

C:\>procdump -64 -ma -c 90 -s 5 -o PID c:\PID.dmp

Figure 3, a ProcDump command to capture CPU consumption

Then you can use tools like Debug Diagnostic or WinDbg to analyze the memory dump and find out what is consuming the CPU.