CLD at TO roll

[Browncbr1]

I noticed the CLD alarm going off on takeoff roll recently.  We have had cooler weather, so that might be what is causing it, but wanted to check if anyone has any advice.

my CLD alarm is set to 30 degrees per minute.  the only cylinder temp that goes down is #4.  I assume it drops from the increased air flow at the beginning of TO, but none of the other cylinders do this.  There is no vibration or noticeable loss of power.  #4 CHT drops about 20 degrees, then starts to go back up..  OAT was 53F.  This hasn't happened in the past with warmer OAT.   Any ideas or concerns I should watch for?

 

Gami spread at 2500rpm/21" is .8 with #3 and #4 peaking together before #1 and #2 together.

Gami spread at 2250rpm/23" is .6 with the same peaking tendencies.

 

I have tanis probe CHT collars for the JPI.. I'm going to check to see if the sleeve slid off or something, thus allowing air to flow directly on to the cht probe.

 

 

[M20F]

Probe going bad would be my guess. 

[Browncbr1]

After thinking more, I think the #4 tanis probe and CHT collar may be getting loose or the fire sleeve may have come off..  I had replaced the tanis probe a month ago and may not have gotten it tight enough.