Mailing List lml@lancaironline.net Message #69761
From: John Barrett <jbarrett@carbinge.com>
Sender: <marv@lancaironline.net>
Subject: RE: [LML] Re: Oil Temp Sensor
Date: Tue, 15 Apr 2014 11:59:29 -0400
To: <lml@lancaironline.net>

Thanks Colyn,

 

I think I’ve pretty well narrowed it down to damaged wiring between sensor and first connection forward of firewall.  I figure it is probably right where the wires come out of the sensor plug.  Wiggling the wires at that point bring about a logical reading on the gauge.  Will contact GRT. 

 

I am still wondering if the wires out of the plug are serviceable.  Doubtful, but would be nice to know if anyone has experience with that.

 

Thanks,
John

 

From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Colyn Case
Sent: Tuesday, April 15, 2014 7:51 AM
To: Lancair Mailing List
Subject: [LML] Re: Oil Temp Sensor

 

other than the physical connection, the choice of which sensor has more to do with the EAU than anything else.  I would call GRT and order from them.   I assume you have eliminated a faulty ground from the equation?

 

Colyn

 

On Apr 15, 2014, at 8:00 AM, John Barrett wrote:



Hello,

 

A couple of weeks ago I asked about an oil temp sensor issue with my IVP TSIO 550.  I took the prevailing advice that the sensor was unlikely to be the failure point and therefore followed out the connections, replacing the ones that were suspect and checking other connectors for contact.  Nothing I did improved the situation and in fact the oil temp readings I am getting now are beginning to interfere with flight because the temp reverts to 59 degrees when the temp gets around 90 degrees whereas it wasn’t happening until about 130 degrees or so – sometime after takeoff the first few times it occurred.  The current condition makes it difficult to assure that the temp is up to 120 degrees prior to takeoff.  This is the minimum oil temp I have been advised to take off with.

 

Today I tried a new experiment.  A little while after engine shut down the oil temp gauge was reading 59 degrees and I knew the oil was much warmer than that, so I tried disconnecting and reconnecting the wires where the probe attaches to a/c wiring.  That made no difference in the reading on the gauge, so I then tried manipulating the wire where it comes out of the sensor probe and the result was immediate – 85 degrees I think it was.

 

My conclusion is that it is the sensor and the wires coming out of the probe have been damaged, so I think I need a new sensor probe. 

 

I was given a sensor probe recently that appears to be new but has no markings on it that I can find.  I tried hooking it up and the resulting indication with warm or cold engine is about 300 degrees.  Same if I reverse the polarity. 

 

With the  existing sensor that I think is failing the oil temp reading never reads below 59 degrees.  In fact when I disconnect the wires, the reading is the same.  Is this normal?  I have the Grand Rapids EAU feeding Chelton MFDs and feeding Vertical Power. 

 

Looking in A/C Spruce I am not able to tell what sensor to purchase and I think that’s what I need.

 

Anyone have an answer?  TCM appears to be inaccessible unless you have an account with them?  Is there a way to get a response from them?

 

Thanks,
John

 

 

 

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