GRT Oil Temperature sensor fail - D180

[SammyQ2]

FYI - after failing to troubleshoot my apparent ground issues in my composite aircraft I installed the GRT oil temp sensor.

It worked great for about an hour, then failed.  When I checked it, it failed as an open ~ infinity ohms.

GRT FedExed me another one, and it failed in about 20 minutes of operation

Both sensors seemed to give up the ghost when the oil temp hit about 200 - 205 F.

I delivered one of the bad sensors to the president of GRT, at Oshkosh this week.  He said he he had a similar failure this week from a different customer and that he would investigate and get back to me.  When I hear back, I will report back to this forum.

The terrible thing for me, is to change the sensor, I have to pull the engine.  :'(

 

[jakej]

Do you have to have the GRT unit ? The Dynon (VDO?) never seems to fail.

Jake J

 

[SammyQ2]

I installed the GRT because, despite my considerable efforts, I was not able to kill the single-wire ground issue. Hence, I tried the GRT sensor.

It worked great until it failed.

 

[jakej]

I understand, however it's not hard to clamp a ground wire to the sensor, have done it to many aircraft including my own

Jake J

 

[SammyQ2]

Actually, in my installation is it impossible to even do that without pulling the engine (4 hrs off, 4 hrs on).  This week at Oshkosh,  Dynon design engineer Ian said that extra wire would not help, so I am understandably reluctant to just "try" something if I am not really sure it will work.
See this post: http://samhoskins.blogspot.com/2011/07/plodding-through-it-all.html

 

[jakej]

Now I understand, you have a Q200 - I know of these (a friend had one).

Is there anywhere else suitable you could install the sender ? Or get another better/good quality sender so you don't have to repeat this again ?

Jake J

 

[SammyQ2]

I am open to suggestions for another 2 wire sender, but my calls to Dynon resulted in their recommendation for the GRT sensor, p.n. FT-LC-01.

All temperature standards, i.e. redline, are measured at the O-200 accessory case. Therefore, mounting it somewhere else would result in a different reference temperature, something I sure don't want to do.

We'll see what GRT comes up with in the next few days and I'll report back. If they don't have anything definitive for a fix, I' guess I'll go back to chasing the bad ground.

 

[jakej]

Sure wish you the best here. If it is a bad ground, as you suggested, I'd be checking the crimped on terminals as they can give problems that are sometimes not immediately apparent.

Jake J