Wednesday, June 13, 2012

CHT Issues

I have noticed the last few flights that my CHT numbers are showing quite a difference from the CHT gasket type sensor vs the one CHT bayonet probe.  The number one and number two cylinders, both up front and get the most air,are starting to top 400-415 degrees in cruise climb configuration.  All the while the number three cylinder, in the back, with the only bayonet probe is topping out at 375ish. I think the washers are shot.
The current CHT washers- Cylinders 1, 2 and 4

The new CHT Probe
Example of a baffle system (blue trim)
Last annual we took a look at the the cylinder fins to make sure there was no casting problems with "slag" for lack of a better term, everything was clear.  I also carefully looked at my existing engine baffles. I am scheduling a time with the shop to take 08Romeo in to talk about replacing the baffles while I have the CHT probes replaced. Just ordered the Alcor probes for @$60 each. The JPI home page FAQ confirmed the Alcors can replace the 5050T JPI probes that run $120 each.

More to follow.....

New Probes installed.


Frank Van Haste said...


On Continental cylinders, it's normal for the spark-plug type CHT probes to read about 40 degrees hotter than the well-types. Not sure about Lycomings.


Gary said...


I'm thinking they are pretty much the same. I will get the probes installed this week before we head back to OCMD next weekend. I hope to see better numbers!