---------------------------------------------------------- RVSouthEast-List Digest Archive --- Total Messages Posted Mon 03/15/10: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:03 PM - Mystery of the low CHT solved (Bill Boyd) 2. 02:23 PM - Re: Mystery of the low CHT solved (Bill Boyd) 3. 10:59 PM - Re: Mystery of the low CHT solved (Larry Bowen) ________________________________ Message 1 _____________________________________ Time: 12:03:56 PM PST US Subject: RVSouthEast-List: Mystery of the low CHT solved From: Bill Boyd Cause of my recent low (190-210*F) CHT's on #4 cylinder, with normal pre-start readings and normal EGT's and power in flight, was just what one might suspect before even pulling the cowl - a faulty sensor; in this case, dangling free of the cylinder head, leaning against the intake manifold tube. What's curious is how the twist and lock spring-loaded connector came loose on this bayonet probe: the tiny spot-welded pin that protrudes radially from the side of stainless barrel that screws into the cylinder head, which the probe cap is slotted to lock upon, fell out of its hole. I will find out soon if I need to buy a whole new sensor or just the mounting assembly. These probes are 12 years old and have 750 hours on them. I see no way to anticipate or detect this kind of failure before it happens. Fortunately, it's not a big safety-of-flight item to suddenly get a low CHT reading if the engine is still making normal power. Off to call GRT and see what's available in the way of spare parts... -Stormy ________________________________ Message 2 _____________________________________ Time: 02:23:56 PM PST US Subject: Re: RVSouthEast-List: Mystery of the low CHT solved From: Bill Boyd "Here. Let me Google that for you..." Answered my own question with a trip to the GRT website - they sell replacement screw-in bayonet probe adapters for 5 bucks. I'll be good to go when the mail runs later this week. -Stormy On Mon, Mar 15, 2010 at 11:36 AM, Bill Boyd wrote: > Cause of my recent low (190-210*F) CHT's on #4 cylinder, with normal > pre-start readings and normal EGT's and power in flight, was just what one > might suspect before even pulling the cowl - a faulty sensor; in this case, > dangling free of the cylinder head, leaning against the intake manifold > tube. > > What's curious is how the twist and lock spring-loaded connector came loose > on this bayonet probe: the tiny spot-welded pin that protrudes radially from > the side of stainless barrel that screws into the cylinder head, which the > probe cap is slotted to lock upon, fell out of its hole. I will find out > soon if I need to buy a whole new sensor or just the mounting assembly. > These probes are 12 years old and have 750 hours on them. I see no way to > anticipate or detect this kind of failure before it happens. Fortunately, > it's not a big safety-of-flight item to suddenly get a low CHT reading if > the engine is still making normal power. > > Off to call GRT and see what's available in the way of spare parts... > > -Stormy > > * > > * > > ________________________________ Message 3 _____________________________________ Time: 10:59:15 PM PST US Subject: Re: RVSouthEast-List: Mystery of the low CHT solved From: Larry Bowen In case you or someone else missed the reference to "let me google that for you" See http://lmgtfy.com. Or in this example: http://lmgtfy.com/?q=cht+bayonet+probe+adapters :) -- Larry Bowen Larry@BowenAero.com http://BowenAero.com On Mon, Mar 15, 2010 at 4:51 PM, Bill Boyd wrote: > "Here. Let me Google that for you..." > > Answered my own question with a trip to the GRT website - they sell > replacement screw-in bayonet probe adapters for 5 bucks. I'll be good to go > when the mail runs later this week. > > -Stormy > > On Mon, Mar 15, 2010 at 11:36 AM, Bill Boyd wrote: > >> Cause of my recent low (190-210*F) CHT's on #4 cylinder, with normal >> pre-start readings and normal EGT's and power in flight, was just what one >> might suspect before even pulling the cowl - a faulty sensor; in this case, >> dangling free of the cylinder head, leaning against the intake manifold >> tube. >> >> What's curious is how the twist and lock spring-loaded connector came >> loose on this bayonet probe: the tiny spot-welded pin that protrudes >> radially from the side of stainless barrel that screws into the cylinder >> head, which the probe cap is slotted to lock upon, fell out of its hole. I >> will find out soon if I need to buy a whole new sensor or just the mounting >> assembly. These probes are 12 years old and have 750 hours on them. I see >> no way to anticipate or detect this kind of failure before it happens. >> Fortunately, it's not a big safety-of-flight item to suddenly get a low CHT >> reading if the engine is still making normal power. >> >> Off to call GRT and see what's available in the way of spare parts... >> >> -Stormy >> >> * >> >> st" target="_blank">http://www.matronics.com/Navigator?RVSouthEast-List >> tp://forums.matronics.com >> _blank">http://www.matronics.com/contribution >> * >> >> > * > > * > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rvsoutheast-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RVSouthEast-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rvsoutheast-list Browse Digests http://www.matronics.com/digest/rvsoutheast-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.