Oil temp needle wiggles

[Rob S.]

Never noticed this before. Needle seems rock solid as it warms up and goes past 160. When it approaches the middle, 210 (which it rarely goes past since installing an oil cooler), it seems to waggle a bit. Sign of old age? Harbinger of bad things?

 

[Redman]

Is the wiggle kinda slow...? Like goes up slowly for a portion of a minute, then goes down a bit in a few seconds.... and repeat....?

Does you oil cooler have something of a theremostate that opens and closes the oil flow thru the cooler....? If so that could be the the oil temp rizing about the setpoint, then thermostate opening, and the temp going down, the thermostate closeing, then the temp rizing.... and so on....?

 

[Rob S.]

Not a slow wiggle, and no thermostat.

 

[Cipher]

voltage regulation?

 

[Rob S.]

voltage regulation?

I don't know. You're talking about the regulator/rectifier, correct?

I have no reason to suspect it's not the original 1982 R/R. And come to think of it, I don't really think it wiggled at idle. I'll have to check next time I ride. For whatever reason, when I'm doing 70 - 80 on the highway, I tend to look at that gauge. Probably because before I installed the 1150 cooler, temp used to hit around 300 in the summer.

 

[gs11ezrydr]

My 82 1100E did that in a way.It would rise slowly like normal then after operating temp bounce up and down like mad.Did all charging test ect.Replaced the oil temp sending unit same problem. Olmed all wires ect. going to gauge and wherever.I found a 140 speedo gauge assy.Fixed. So it was the gauge in this case..The sending unit was over 60$ 15 years ago (Wasted) But in your case could be anything in the circuit as I described. Good luck.

 

[Rob S.]

I've decided that it's slight variations in (voltage, wattage, resistance)?

It's only at 5k or higher revs that it wiggles, and it's not an extreme shaking. At warm up and idle, it's rock steady. If it ain't broke...

As you can tell, I didn't inherit my father's abilities. He was an electrician on a minesweeper/destroyer in the Pacific in WWII, and in later years if anything in the house or car broke, he fixed it. I watched, but we weren't that close so I didin't ask and he didn't tell.

At least I can see the oil temp while while I'm riding. Not like my stupid Harley.

 

[Brendan W]

Funny, if this was an oil pressure gauge no one would bat an eyelid.
If I knew what I was talking about I might try sizing a capacitor to put across the sender.
At a guess the sensor is more sensitive to fluctuations at higher temperatures because the current is different.
Then I don't see anyone putting accumulators on pressure gauges
What are the chances that the needle is picking up a harmonic at 5k and resonating to the engine vibes.
Does putting on turn signals make it worse better?

 

[Rob S.]

Does putting on turn signals make it worse better?

Have to get back to you on that one.

 

[Gorminrider]

i don't know but there's some excellent answers here! Try em! but you could also see if an old-fashioned "analogue" voltmeter (non-digital-you know- the one like your dad had) across the gauge's contacts also fluctuates...this might indicate that your temp gauge is tired and worn at it's little bearings or the sensor in the oil is tired.