- Joined
- Mar 5, 2017
- Messages
- 784
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- 314
I’m trying to track down the reason for a relatively hot CHT #5. I have already plugged up every conceivable hole and gap in the baffle seals, and that did bring down the max temperature during climb by 20 degrees or so. I am still chasing the temperature issue because this cylinder is an outlier in a few ways. First, while the CHT on the other cylinders are within 20 degrees of each other, the #5 CHT is often about 40 degrees hotter than the next hottest cylinder. Second, during departure, this cylinder shoots up in temperature much more than the other cylinders and is the only one to exceed 380-390 degrees (the good news is that it settles down to 370 to 380’s when I push the nose down to 100kias for the rest of the climb to my final altitude). Third, this is the most sensitive cylinder to any leaning on the mixture control in that the EGTs climb the quickest; also, this is the last cylinder to peak by a mile.
I have not switched the probes to see if this is an instrumentation problem. I have not had my A&P check for an induction leak although I don’t think that this is what this is. All of that is to come.
In the meantime, here is my question: I have often wondered about the position of the oil cooler on the back of the aluminum baffle. Mine sits on the aft-copilot side right behind the #5 cylinder, and I have always wondered if this is the way it’s supposed to be. If I’m working hard to seal these holes in the baffle seals, then how can that oil cooler not be robbing some seal and therefore reducing the pressure differential between the upper and lower aspects of the engine compartment? I am including a picture asking if this is the position of your oil cooler on your Cherokee, especially on the Dakotas. Would putting RTV around the margin of the oil cooler where it contacts the aluminum baffle make sense? Am I barking up the wrong tree? Any input would be appreciated.
Thank you in advance!
