Dual Oil Temp Probes

[logansc]

Looked around but didn't find a thread on this one; so, here goes...surely someone has run into this before me:

I have both an EDM engine monitor and two separate gages, one for oil pressue and one for temperature. The two "steam" gages are purely backup instruments which I expect will be little more than cosmetic most of the time. The problem comes in hooking them up. I've worked out what to do with the extra oil pressure transducer, but there is only one place on my engine (IO-540K) for a temperature probe and that's on the back end of my oil filter adapter. I have that one running to my EDM 900. Any ideas on a good place to put the temp probe for my Chief oil temp gage? Ideas so far are to "T" off of the back of the oil cooler adapter and put one probe on each T or to do the same off of the oil cooler itself with an in-line "T" for the second probe. Another (better, I think) idea is to drill the spare sump plug and tap it for the second temp probe.

Won't give the same temp in each place (except maybe for the first idea) but that should be no problem. Might be interesting to know the temps in two different parts of the engine. Either way, both these gages are just backups if the EDM suffers a BSOD.

Anyway, those ideas notwithstanding, what have others done?

Regards,


Lee...

[N941WR]

Originally Posted by logansc

...Won't give the same temp in each place (except maybe for the first idea) but that should be no problem. Might be interesting to know the temps in two different parts of the engine. Either way, both these gages are just backups if the EDM suffers a BSOD...

Lee,

Lycoming told us that the oil temps in the sump are over 212 degrees F, which is normal. The Lycoming rep went on to say the oil temps in the sump are the reason why you only need to get the temps up to 180 -190*F to get the moisture out.

The problem with putting an oil temp probe someplace else is you will have a challenge correlating what are "normal" and "correct" temps.

[logansc]

Good point, Bill...and I agree. What I would expect to see in that situation would be oil temps in the neighborhood of 180-200 on the EDM 900 from the temp probe on the oil filter adapter and maybe 20 degrees or more higher than that in the sump. If my EDM fails, then at least I would have an indication of the engines cooling health by reference to the other gage---even though it registers higher than the EDM probe, it should do so consistently and I should have an idea of what it is normally. As long as it stays at 200 (or whatever), I would be seeing "normal" ops. I'd be comfortable flying that way until I could get home and find out what went wrong with the electronic wonder box.

Still accepting other ideas for where to put the second probe, though!

Regards,


Lee...

[170 driver]

search threads "alternate oil temp probe location" there is a picture there of one

[N54SG]

I have one on the oil filter adapter, and the second is mounted on a T fitting on the oil cooler exit. That way I can see how effective the oil cooler is.

If you going to get 2 different numbers for sure, might as well gauge the oil cooler.

[mbick]

I haven't looked at a 540 lately but they should have a set screw in the oil galley in the front of the engine that could be used. JPI 700 install instructions tells you to use that if you already have used the standard location. Hope that helps. Might be a little small though for the prob.

[logansc]

Good point, Mike. I missed that, I'll take a look at the front of my engine tonight...

Thanks to all who've responded.

Regards,


Lee...