engine oil temp sensor

[GuzziMoto]

My wifes V11 has goo in the stock holder.

Anything you do that improves heat transfer from the motor to the sensor will improve its accuracy. Improving the sensors accuracy does not mean your bike will run better automatically, but it is a step in the right direction. But if your bike was border line lean at some rpm or throttle position then improving the accuracy of the ETS may make it run worse at that point instead of better. But many bikes, and V11s for sure, are a little lean at lower rpms and throttle openings and too rich at higher rpms and throttle openings. Therefore bodging the ETS to richen up the mix at idle will improve the way the bike runs there but since the motor was already too rich elsewhere it will only be worse there.

Improving the accuracy of the sensor is not the same as "making the bike run hot". If it is too lean it will run a little hot, but the sensor itself does not cause this. It just measures it.

[Greg Field]

Very good! Page 37. Carry on . . .

[dlaing]

My wifes V11 has goo in the stock holder.

Anything you do that improves heat transfer from the motor to the sensor will improve its accuracy. Improving the sensors accuracy does not mean your bike will run better automatically, but it is a step in the right direction. But if your bike was border line lean at some rpm or throttle position then improving the accuracy of the ETS may make it run worse at that point instead of better. But many bikes, and V11s for sure, are a little lean at lower rpms and throttle openings and too rich at higher rpms and throttle openings. Therefore bodging the ETS to richen up the mix at idle will improve the way the bike runs there but since the motor was already too rich elsewhere it will only be worse there.

Improving the accuracy of the sensor is not the same as "making the bike run hot". If it is too lean it will run a little hot, but the sensor itself does not cause this. It just measures it.

I think we now have two definitions of accuracy.

There is the accuracy of the sensor following the engine temperature, and there is the accuracy of the sensor output matching the table in the ECU.

Adding goo helps the sensor follow the engine, but we really aren't sure about how it matches the table in the ECU.

It appears that adding goo makes it better match the table at cold temps and at hot temps it is a worse match.

Theoretically the stock set up should have matched it best.

Guzzi engineers may have figured on making it nice and rich at temperatures that won't be tested for emissions.

As for it being too rich at higher RPMs and throttle openings, I don't think that is true, except for a couple of cells on the map.

As evidence, look at the PCIII map for a stock Guzzi, where almost all changes are to make it run richer indicating it was too lean to begin with.

But that raises another point about what the temperature was when the bike was dyno'd. How do the tuning link dyno? I seem to recall they hold it one throttle position and let it go through the revs, and then move to the next throttle position getting more and more open as they go, so probably the engine is probably coolest under low throttles and hottest at high throttles, throwing off the values.

Another problem is that many dealers may be doing the "favor" of setting the trim (or TPS) richer than EPA mandated spec. Adding goo may be seen to have a positive effect because of that.

[dlaing]

+1 to all of that. Some coonhounds're wasting time at the base of the wrong tree . . .

How's that duct tape holding up on the sensor?

What are we wasting time on?

Reducing thermal diffusivity?

A resistor that helps reduce overly lean conditions, and gives feedback to the running condition?

Criticism of recommending the brass adapter?

Criticism of the advice of adding goo?

Criticism of the advice of adding duct tape?

I think someone else is barking up the wrong tree.

[GuzziMoto]

I think we now have two definitions of accuracy.

There is the accuracy of the sensor following the engine temperature, and there is the accuracy of the sensor output matching the table in the ECU.

Adding goo helps the sensor follow the engine, but we really aren't sure about how it matches the table in the ECU.

It appears that adding goo makes it better match the table at cold temps and at hot temps it is a worse match.

 

There is only matching the sensor temp (and therefore it reading) to the temp of the engine. The table in the ECU is what the ECU does with the information the sensors send it. There is no "sensor output matching the table in the ECU". Again, causing the sensor to read low will trick the ECU into giving the motor more fuel at all rpms, and that may seem to correct an issue with the bike being lean at low revs and throttle openings. But it will also add more fuel at higher revs and throttle openings that the motor does not need, not to mention it does not address what was causing the lean condition to begin with. It is a band-aid fix that treats the symptom, not the problem.

 

Guzzi engineers may have figured on making it nice and rich at temperatures that won't be tested for emissions.

As for it being too rich at higher RPMs and throttle openings, I don't think that is true, except for a couple of cells on the map.

As evidence, look at the PCIII map for a stock Guzzi, where almost all changes are to make it run richer indicating it was too lean to begin with.

 

Emissions testing is not done at full throttle and high rpms so Guzzi and most others (especially with air cooled motors) set the bike up either with correct fueling or rich fueling in those areas. It is only in the lower revs and throttle openings that the motor is lean, and there it should not be so lean that it runs as you describe having issues with unless something is not right with the bike. This is not something unique to Guzzi but most if not all the manufacters do this.

But that raises another point about what the temperature was when the bike was dyno'd. How do the tuning link dyno? I seem to recall they hold it one throttle position and let it go through the revs, and then move to the next throttle position getting more and more open as they go, so probably the engine is probably coolest under low throttles and hottest at high throttles, throwing off the values.

 

Any decent dyno operator will keep an eye on engine temp to prevent that from happening.

Another problem is that many dealers may be doing the "favor" of setting the trim (or TPS) richer than EPA mandated spec. Adding goo may be seen to have a positive effect because of that.

 

Adding goo has a positive effect because it gets the bike off of the rich warmup mode quicker then it does without the goo, thus reducing fuel consumption and in most cases improving warmup time (a rich motor will warmup a little slower then on with correct fueling, plus over rich fueling can wash oil off the cylinder walls).

 

The purpose of the ETS is to tell the ECU when the motor is cold so it will add more fuel. That is what it does. Anything you do to improve it accuracy will give the ECU better more acurate info on the temp of the engine. Screwing with that in a way that feeds the ECU inaccurate info is not or will it ever be defined as improving the accuracy of the sensor. It will alter the fueling but it is not improving the accuracy. You cannot put a heatsink on the sensor and then say it is improving the heat flow to the sensor by drawing heat into the sensor. It is doing one thing and one thing only, it is cooling off the sensor causing it to read lower then it should. Call it what you like but it is doing what it does. Heatsinks shed heat cooling off the device they are attached to.

[pete roper]

God's teeth!

 

37 bloody pages!

 

Surely the horse hasn't just been flogged to death it has to be just a bloody smear on the pavement by now

 

Pete

[Dan M]

God's teeth!

 

37 bloody pages!

 

Surely the horse hasn't just been flogged to death it has to be just a bloody smear on the pavement by now

 

Pete

 

 

Can't even smell rotting horse meat anymore

[GuzziMoto]

Move along Pete, nothing for you to see here.

[John in Leeds]

Reading through this thread I could not fail to be amazed by your analytical dissection of this perennial sensor problem. No stone appears to be unturned in the quest for perfection. There is however one area that has not had due consideration - the real nature of current flow in a circuit. I feel qualified to comment on this as the frustrated owner of many British motorcycles using Lucas components.

 

Negative ground systems as used by the V11 depends upon proper circuit functioning, which is the transmission of charged ions by retention of the visible spectral manifestation known as "smoke". Smoke is the thing that makes electrical circuits work; we know this to be true because every time one lets the smoke out of the electrical system, it stops working. This can be verified repeatedly through empirical testing.

 

When, for example, the smoke escapes from an electrical component (like, say, a Lucas voltage regulator), it will be observed that the component stops working. The function of the wire harness is to carry the smoke from one device to another; when the wire harness "springs a leak" and lets all the smoke out of the system, nothing works afterwards. Starter motors were frowned upon in British motorcycles for some time, largely because they consume large quantities of smoke, requiring very large wires.

 

I know that Lucas components are possibly more prone to electrical leakage than Bosch or generic Japanese. Experts point out that this is because Lucas is British and all things British leak. British engines leak oil, shock absorbers and hydraulic forks and disk brakes leak fluid, British tyres leak air, and the British defence establishment leaks secrets... so, naturally, British electrics leak smoke. This does not mean we should not remember basic principals in this quest.

 

From the basic concept of electrical transmission of energy in the form of smoke, a better understanding of the mysteries of electrical components - - even those on the V11 - - is gained by the casual user.

[Greg Field]

How's that duct tape holding up on the sensor?

What are we wasting time on?

Reducing thermal diffusivity?

A resistor that helps reduce overly lean conditions, and gives feedback to the running condition?

Criticism of recommending the brass adapter?

Criticism of the advice of adding goo?

Criticism of the advice of adding duct tape?

I think someone else is barking up the wrong tree.

 

 

Duct tape is doing fine. Bike runs perfectly.

 

By all means, carry on with your quest for a manual choke on your EFI system. Perhaps you could plumb one of those little watering bottles from a hamster cage into your intake. Fill it with gas, and rig up a cable to its vent to allow an extra dribble any time you wanted it. Better yet, why not a sparate bottle and cable control for each side, so you could make a custom "Hamster Commander IV" map for each cylinder? There're dozens of ways of kludging around fixing the real problem. This thread could go on to 90 pages if you 'n Ratch really started thinking "outside the hamster cage." Enquiring hamsters, well, you know . . .

[Guest ratchethack]

. . .I can't see another means by which the sensor can get hotter than that which it is trying to get the temp of (the head).

Managed to get many more hours of experimenting and testing on the road this weekend, more about which later.

 

Here's my understanding of the answer to that Q, based on many weeks of testing the OE sensor and a solid grasp of the fundamentals of thermodynamics -- both of which seem to be extremely rare commodities hereabouts. . .

 

Consider that head temp very seldom reaches a steady state of equilibrium in an air cooled motor. That is, on the road, under varying conditions of speed, throttle, engine RPM, load, ambient temperatures, etc., lacking a cooling jacket to effectively stabilize engine temps, the operating temps of air cooled cylinder heads vary considerably over relatively short timelines (fractions of a minute), and are constantly either heating up or cooling down. It is this temp variance that the ECU attempts to monitor to effectively control pulsewidth signals to the FI.

 

Consider then the OE plastic head temp sensor/holder, with the weight of its ~1.4 oz. sensor body and probe (nearly 100% brass), that weight being a direct indicator of its 1. mass, 2. heat capacity, and 3. thermal inertia when exposed to a heat source higher than ambient.

 

As the motor heats up in operation, the heat of combustion is conducted into the sensor body from the head through the probe end of the sensor (more directly in the case of thermo-paste or less directly through an air space). In either case, heat will flow into the "heat reservoir" of the sensor body from the head until the sensor body is the same temp as the head, and temp equilibrium is attained.

 

In the same way that the heads are always either heating up or cooling down, the temp of the sensor body is also always either heating up or cooling down. The cylinder heads, being at the heat source, must always lead the temp changes at the sensor body by heat flow through the temp probe, and the sensor body temp must always follow temp changes of the heads.

 

The OE temp sensor body/holder lacks both a heat source and an avenue for cooling. The head provides both heating and cooling for the temp sensor body/holder through the only avenue of heat flow between them, a relatively constricted pathway for heat flow -- the sensor probe, where the thermistor is located, and where the temp is actually read.

 

Now consider what happens when conditions on the road change, as when one slows down, descends a long grade, closes the throttles, hauls up to a stop after hard riding, or any combination thereof. In all of these cases, heat production at the source from combustion drops off sharply, and the heads suddenly cool (continue to dump heat) due to air convection via the cooling fins.

 

Now the temp of the heat-soaked sensor body is suddenly higher than the heads, due to the thermal inertia of the sensor body. Lacking any other avenue of escape, the relatively higher heat of the sensor body now flows back into the cooler head and out through the cooling fins. This doesn't happen instantly. It takes time for heat to flow in either direction through the relatively constricted path available to it at the sensor probe.

 

This delay is what I have been referring to as the inherent LAG TIME in temp change response of the OE sensor, and a source of significant inherent ERROR of the OE plastic sensor/holder. This understanding is supported by my weeks of testing and experimenting on the road, and particularly obvious when observing the relief of over-lean heat soak lean burn symptoms when adding a heat sink to the sensor body.

[Greg Field]

Stellar! There's 40 more BQ points.

[gstallons]

If Ratch' could find a way to put breasts on an engine oil temp sensor we could do away with ALL the other forums.

[dlaing]

Managed to get many more hours of experimenting and testing on the road this weekend, more about which later.

 

Here's my understanding of the answer to that Q.

 

Consider that head temp very seldom reaches a steady state of equilibrium in an air cooled motor. That is, on the road, under varying conditions of speed, throttle, engine RPM, load, ambient temperatures, etc., lacking a cooling jacket to effectively stabilize engine temps, the operating temps of air cooled cylinder heads vary considerably over relatively short timelines (fractions of a minute), and are constantly either heating up or cooling down. It is this temp variance that the ECU attempts to monitor to effectively control pulsewidth signals to the FI.

 

Consider then the OE plastic head temp sensor/holder, with the weight of its ~1.4 oz. sensor body and probe (nearly 100% brass), that weight being a direct indicator of its 1. mass, 2. heat capacity, and 3. thermal inertia when exposed to a heat source higher than ambient.

 

As the motor heats up in operation, the heat of combustion is conducted into the sensor body from the head through the probe end of the sensor (more directly in the case of thermo-paste or less directly through an air space). In either case, heat will flow into the "heat reservoir" of the sensor body from the head until the sensor body is the same temp as the head, and temp equilibrium is attained.

 

The OE temp sensor body/holder lacks both a heat source and an avenue for cooling. The head provides both heating and cooling for the temp sensor body/holder through the only avenue of heat flow between them, the relatively constricted (narrower) avenue for heat flow (the sensor probe).

 

In the same way that the heads are always either heating up or cooling down, the temp of the sensor body is also always either heating up or cooling down. The cylinder heads, being at the heat source, must always lead the temp changes at the sensor body by heat flow through the temp probe, and the sensor body temp must always follow temp changes of the heads.

 

Now consider what happens when conditions on the road change, as when one slows down, descends a long grade, closes the throttles, hauls up to a stop after hard riding, or any combination thereof. In all of these cases, heat production at the source from combustion drops off sharply, and the heads suddenly cool due to air convection via the cooling fins.

 

Now the temp of the heat-soaked sensor body is suddenly higher than the heads, due to the thermal inertia of the sensor body. Lacking any other avenue of escape, the relatively higher heat of the sensor body now flows back into the cooler head and out through the cooling fins. It takes time for this heat to flow in either direction through the relatively narrow path available to it at the sensor probe.

 

This is what I have been referring to as the inherent LAG TIME in temp change response of the OE sensor, and a source of significant inherent ERROR of the OE plastic sensor/holder. This understanding is supported by my weeks of testing and experimenting on the road, and particularly obvious when observing the relief of over-lean heat soak lean burn symptoms when using a heat sink on the sensor body.

If Ratchet and I actually agree on something, you guys really need to question your understanding of thermal dynamics.

Everyone is fine with Greg's duct tape???? Is everyone living on the North Pole riding in the snow with square wheels????

[Greg Field]

The gauntlet has been thrown . . .