JPI Oil Temperature Probe Question

[LANCECASPER]

The indicated oil temperature on the JPI EDM 700 has been all over the place since I have owned the airplane for the past three years. All of the other numbers look good. The ship's gauge is consistent and seems to work well. I bought a new JPI oil temp probe last year and installed it during the annual. Now I am wondering if it is installed in the correct location. Those Bravo owners who have JPI engine monitors, where is your oil temp probe installed?  Thanks

[Bravoman]

I’m not sure where mine is installed but if a new probe didnt solve the problem could it be the wiring? I can’t imagine the previous owner, who I know was the original owner, wouldn’t have had it addressed if it were erratic from the get go, which you might assume would be the case if it was due to improper placement. I’m no mechanic but just thinking out loud. Next time I’m at the shop I’ll find out where mine is installed and will report back. 

Edited November 8, 2018 by Bravoman

[carusoam]

See if you can get a part number and manufacturer with that...

Wondering if the O got the same sensor...

It may be airframe more than engine manufacturer...

I might be looking for a solution... one of these days...

Best regards,

-a-

[LANCECASPER]

10 hours ago, Bravoman said:

I’m not sure where mine is installed but if a new probe didnt solve the problem could it be the wiring? I can’t imagine the previous owner, who I know was the original owner, wouldn’t have had it addressed if it were erratic from the get go, which you might assume would be the case if it was due to improper placement. I’m no mechanic but just thinking out loud. Next time I’m at the shop I’ll find out where mine is installed and will report back. 

Thanks. The previous owner had the JPI put in around the time his health was declining so I'm not sure it was ever addressed. I appreciate it.

The wiring is good. It does not show an "OPEN PROBE"

[carusoam]

Things to consider...

The primary OilT location is usually set to one spot...

The sensor is typically a temperature sensitive resistor...

It can fail slowly over time... and act like an open shirt when the failure is complete...

I have only seen one failure. So not a lot of experience...

A dual TC probe would have been much better...

Best regards,

-a-

[LANCECASPER]

Currently the JPI oil temp probe is located on the right side of the back of the engine near the vernatherm which would make sense why the temperature is all over the place (when it opens and closes the indicated oil temp changes). Before starting the engine the probe reads correct ambient temperature, 

The JPI install manual says to install up up near the front of the engine. Am I on the right track?

 

[ArtVandelay]

If installing a 900 and removing your factory gauges, I would install it at factory location since you’re pulling factory sensor anyway.

[LANCECASPER]

35 minutes ago, teejayevans said:

If installing a 900 and removing your factory gauges, I would install it at factory location since you’re pulling factory sensor anyway.

My factory gauges still work very well. I just want the JPI 700 to display an accurate secondary oil temperature. Someday if I cut a new panel I might consider the JPI 900.

[Awful_Charlie]

My oil temp probe for the JPI is installed as per the JPI manual - no problem with unbelievable readings (#3 CHT is unfortunately not the same - problem solving TBD)

Why people decide to install probes in non-approved locations bewilders me - for instance this case was an expensive lesson!

[LANCECASPER]

My oil temp probe for the JPI is installed as per the JPI manual - no problem with unbelievable readings (#3 CHT is unfortunately not the same - problem solving TBD)
Why people decide to install probes in non-approved locations bewilders me - for instance this case was an expensive lesson!

Here’s where my JPI probe is now.


It looks like this would be the location on the front right.


It looks like this would be the location on the front left.

@Awful_Charlie which side is yours on? How did you route the wires for the probe?

Thanks


Sent from my iPhone using Tapatalk

[CWM20f]

3 hours ago, LANCECASPER said:

Currently the JPI oil temp probe is located on the right side of the back of the engine near the vernatherm which would make sense why the temperature is all over the place (when it opens and closes the indicated oil temp changes). Before starting the engine the probe reads correct ambient temperature, 

The JPI install manual says to install up up near the front of the engine. Am I on the right track?

 

Lance -

this is where mine is (photo above co-pilot side port) and works fine. Ran wire along top of engine and out co-pilot side baffle. Side note - got led light yesterday.  Works great Thanks!

Edited November 8, 2018 by CWM20f

[CWM20f]

12 minutes ago, LANCECASPER said:

right.

 

This is the spot I used.  Mine is IO-360 but the front looks identical as far as oil ports. 

[LANCECASPER]

My IA is here today and we are putting in in the right front of the engine. Next flight I'll report back on whether I get accurate temperatures now in this location.

[carusoam]

That has got to be a great location splashing oil is everywhere, I think...?

is that an open area where the piston rods are moving in and out?

Best regards,

-a-

[tls pilot]

Lance

Mine is installed in the front

Not sure why Jaime's mechanic installed that probe in the spot you show

With mine in the front, the oil temps are nearly exact in all conditions

 

[N231BN]

That has got to be a great location splashing oil is everywhere, I think...?
is that an open area where the piston rods are moving in and out?
Best regards,
-a-

That is the end of the oil gallery that supplies the lifters.

[LANCECASPER]

On 11/9/2018 at 5:12 PM, tls pilot said:

Lance

Mine is installed in the front

Not sure why Jaime's mechanic installed that probe in the spot you show

With mine in the front, the oil temps are nearly exact in all conditions

 

Thanks!   University Air at Gainesville, FL installed Jaime's JPI. They had done the work on his airplane for about the last ten years he owned it. Not sure why they put the oil temp probe specifically where the tag on the probe said not to put it. They helped me with a buyer assist pre-buy before I bought it and arranged for the ferry permit to bring it back to TX. They seem like a competent shop but missed a few Mooney specific items over the years they serviced it.

I'm changing out tires, tubes and replacing brakes, changing o-rings in the calipers, bleeding the brake lines and when everything is put back together next week I'll report back on the JPI oil temp probe. 

[Awful_Charlie]

On 11/8/2018 at 9:54 PM, LANCECASPER said:

@Awful_Charlie which side is yours on? How did you route the wires for the probe?

Thanks


Sent from my iPhone using Tapatalk

 

Mine is where you have re-located yours too - good job :-)

Wire routes with the unconnected prop heater underneath the barrels to go through the firewall on the starboard side with the starter cable (and the rest of the JPI leads)
Not a great picture - EGT and cylinder probes are on the stand-offs with the lower HT leads, Oli temp just visible at the back

[LANCECASPER]

2 hours ago, Awful_Charlie said:

Mine is where you have re-located yours too - good job :-)

Wire routes with the unconnected prop heater underneath the barrels to go through the firewall on the starboard side with the starter cable (and the rest of the JPI leads)
Not a great picture - EGT and cylinder probes are on the stand-offs with the lower HT leads, Oli temp just visible at the back

Thanks!

[LANCECASPER]

Update - i ran up the engine last night and still getting strange readings from the  JPI oil temp probe. It started out at ambient temp (70 F) and kept dropping a degree at at time until shutdown (38 F). My ship's gauge showed the oil temp at just over 100 F. . . 

[N231BN]

What was the outside air temp?

Update - i ran up the engine last night and still getting strange readings from the  JPI oil temp probe. It started out at ambient temp (70 F) and kept dropping a degree at at time until shutdown (38 F). My ship's gauge showed the oil temp at just over 100 F. . . 

[LANCECASPER]

1 minute ago, N231BN said:

What was the outside air temp?

The ambient air temp outside was 70 F.

[CWM20f]

Is the JPI grounded to the engine block?  

[LANCECASPER]

2 minutes ago, CWM20f said:

Is the JPI grounded to the engine block?  

Since the probe screws into the block I would think it is.

[CWM20f]

There is a dedicated ground wire from the JPI unit the should be grounded to engine block. If not or if bad connection it could cause crazy readings.