I've been using a digital oil temp dipstick on my 2011 103" Street Glide.

On a hot days, dipstick temps will read up to ~278*, and my EITMS kicks in.

Today, I installed a HD dash-mount oil temp gauge.

However, when the dash gauge reads ~230*, the dipstick reads ~257*. There seems to be a 25*-30* discrepancy between the two.

Which reading should I believe?

Is there a way to test each unit, to see which is truly accurate?

I know these digital oil temp dipsticks get a bad rap, but I used this exact one on my Road King last year and never had a problem. Typical Road King temps would read ~230* on the dipstick.

Thanks

 

Where's your sending unit?The dip stick gauge is pretty accurate when it's working.Those higher temps. are about right if your bikes all stock.ETMS is supposed to kick in @ 270*

 

On the dash gage.....the numbers do not necessarily 'line-up' with the 'hash marks'..
if you know what I mean. Seems, if I recall....the numbers are to the right of the corosponding mark on the gage...
When I had a bike with the dash gage....I figured as long as the needle wasn't
past the halfway mark.....
all was good.
After awhile, I never payed attention to the gage.

chuck

 

Sounds like the dipstick is about right. You can always check it in some boiling water. I have seen a few installs of the sending unit for the dash gauge done incorrectly. Either not installed deep enough or the wrong sender was used. Was an adapter used for the sending unit?

 

That's just like having 2 clocks... never know what time it really is.

I'd check the dipstick in some boiling water and use another thermometer to verify.

 

I have both gauges and have experienced the same difference between the two. I believe the reason is that the oil in the pan is actually cooler than the oil at the dip stick.

 

Sending unit for the dash gauge is in the oil pan, right next to the drain plug.

 

I used the adapter that came with the HD oil gauge kit, and followed all directions explicitly.

FWIW, the adapter seated very deeply in the oil pan, and the sending unit also seated very deeply in the adapter.

Thanks

 

Hmm..., 30* cooler?

I'm not so sure about there being a temp difference in the two locations.

Thanks

 

Pan sender for most add on oil temp gauges has a bushing to mostly soak up pan temp because the bushing provides shielding to the probe from oil in motion from the way that I see it. Additionally the pan can be cooler, one it has more exposed air surface area and its at a low point. Heat rises. The dip stick is higher and contained higher in the oil flow so it realisticly can get a stream of higher temp oil straight out of the crank case and give that reading before the oil gets mixed with what is at the bottom of the pan.

As suggested, take a calibration reading with some boiling water to test you stick and you could take a IR Temp reading from the pan to see if it reflects what the pan probe is actually picking up. Then base your oil temps accordingly.