engine oil temp sensor

[Guzzi2Go]

...

Essentially, the OilT line says that as long as the part of the EXTERIOR of the head where the holder is seated (REMINDER: this is not the INTERIOR OF THE HEAD) is below body temp, the sensor will be boosting the pulsewidth and A/F by bumping up the map, and there's NO BOOST to the A/F above that.

 

So once the EXTERIOR of the head is above body temp, and it's running, this says we may ignore both the OilT and Crank lines and focus exclusively on the TempR line.

 

On the TempR line, I'm focused on wot's happening between 40°C to 125°C, which is a drop in resistance of half again greater than an order of magnitude. This appears to be the only relevant data to consider here once the motor is warmed up to operating temp and running. It's exactly where I've consistently observed the undesirable driveability anomalies (apparent over-lean condition) caused by adding thermal paste/lead for a direct thermal connection between holder base and sensor tip using the plastic holder.

...

Not sure if I understand all this correctly, it is too much of English at once for me.

 

The ONLY RELEVANT line here is the OilT line, unless there are other lines not made available to general public. What is written in this line contradicts three statements made in this discussion:

1) Oil temp sensor is used for fine tuning fuel/air ratio throughout the entire working temperature range. It does not, as it shuts off after 40°C. That is a hot summer day for people that deal with Fahrenheits. In other words not much.

2) Mixture gets richer if engine gets too hot for the purpose of cooling. Same here, since there is no evidence of "movement" in either direction beyond 40°C.

3) If thermal paste is used, engine will run leaner. It can't! All that thermal paste will do is to allow the sensor to heat up quicker and stay like that. Again, 40°C is not much, even for the head surface temp.

 

So why does the engine appear to be running lean when the paste is added? It sure does, at least I have the same impression. Does it consume more fuel and runs rich on a cold winter day if the paste is not there? It sure does. But why? Is Weber-Marelli unit's map that different?

 

Furthermore, TempR line is simply characteristics of the WTS05 sensor. One can read it out of the datasheet, or do as Cliff did - measure it. It is used as input to the ECU, whereas OilT line is a function of that input which is together with a few more values, used towards the ECU's output stage.

[Guest ratchethack]

The ONLY RELEVANT line here is the OilT line, unless there are other lines not made available to general public.

^We have entirely different interpretations of the data here, G2G.

So why does the engine appear to be running lean when the paste is added? It sure does, at least I have the same impression. Does it consume more fuel and runs rich on a cold winter day if the paste is not there? It sure does. But why? Is Weber-Marelli unit's map that different?

Regardless of Weber-Marelli map or a custom map, I b'lieve the answers to these questions are the same, and they appeared in my previous post to the best of my current understanding:

Essentially, the OilT "choking boost" line says...there's NO BOOST to the A/F above [40°C].

 

The Crank boost decays to 0 at ~20 seconds, so once the EXTERIOR of the head is above [40°C], and it's been running >20 sec., this says we may ignore both the OilT and Crank lines and focus exclusively on the TempR line.

 

The TempR line. . .appears to be the only relevant data to consider here once the motor is warmed up to operating temp and running. It's at the high temp end of this range where I've consistently observed the undesirable low-RPM driveability anomalies (apparent over-lean condition) caused by adding thermal paste for a direct thermal connection between holder base and sensor tip using the plastic holder.

But o' course, somebody's M is without much question gonna V. . .

 

. . . And waddayagonna do?

[Skeeve]

So why does the engine appear to be running lean when the paste is added? It sure does, at least I have the same impression. Does it consume more fuel and runs rich on a cold winter day if the paste is not there? It sure does. But why? Is Weber-Marelli unit's map that different?

 

I think the factory got a Harley TPS in there by mistake when they were making the map...

 

I think it comes down to this:

 

The factory map is messed up. We can fudge certain aspects of it by our own adjustments to the TPS, etc., or we can go whole hog & make a new map [whether via VSDSTITTTIES, TuneBoyeeee, or PCIII&1/2ussr or what have you.] Making a whole new map enables us to bypass the flaws in certain areas; fudging the stock map is inevitably a choice between various tradeoffs.

 

For those living in cold climates or suffering from poor mileage, eliminating the cold-engine overrich condition may be more important than the excessive leanness on hot days. For those of us fortunate to be living in climates where it rarely, if ever, gets cold enough to worry about the cold-motor symptoms, we'll definitely choose to trade that off for more fuel at high temps for better power and responsiveness.

 

In the mean time, we all get to kvetch to each other about what tradeoffs we prefer on this magnificent forum. Thanks Jaap!

[Guest ratchethack]

The factory map is messed up. . . .fudging the stock map is inevitably a choice between various tradeoffs.

Yes indeed. Again, taking another swag at this for clarity (because I b'lieve this is not yet well understood, and I b'lieve I've got it pretty well nailed down now, though not 100% certain):

 

One of the significant contributors to the fact that the factory map is wonky appears to be that it was CREATED by reading the wonky factory sensor/holder setup, which doesn't provide either a consistent or accurate signal to the ECU. The read it provides to the ECU is highly susceptible to both variances in the heat stage of the motor, AND in the quality of the airflow over the motor when the map is created, which tends to throw a wide range of variable read signals into the mix. Evidently, it was determined that a direct read off the sensor (full thermal connection) was even worse according to the Luigi's, otherwise they'd have produced them this way. Evidently (Part II), a map that could satisfactorily deal with the error over a wide range of operating conditions could not be created with a direct connection. So, as they clearly and deliberately did with the previous brass holder (to the tune of .25", or ~6.3 mm), they evidently AGAIN introduced an AIR GAP, this time only ~.015" (~.4 mm), which (as it appears to've done in my case) tended to spread and/or delay the error, providing more acceptable operation over a wider range of road conditions. However, this still leaves potential for SIGNIFICANT ERROR in both directions: In the creation of the map (any map), AND AGAIN in attempting to compensate for the error that gets built into the map after the fact.

 

. . .At least that's my read, and until I'm corrected by superior intelligence and/or logic, I'm stickin' to it.

 

By all means, have at it, Gents!

 

Wherefore art thou, Dr. John and Cliff?

[Guzzi2Go]

Well ratchet, I still don't understand your fascination with the TempR line. Can you elaborate on that?

 

I am not arguing that I am not seeing the same effects as you do, I am finding it hard to undertsand your arguments.

 

The TempR line is a constant. It just shows how NTC's resistance changes under influence of heat. You can read this line out of the sensor's datasheet. Google for WTS05, and you'll find the TempR line in the Technical data section.

 

According to Cliff, there are only two lines that are influenced by the NTC. The OilT and AirT.

# OilT is the permanent choking boost
#Temp C   -30    -20     -10        0    10    20    25    30    40    50    60    70    80    90   100   110   125
OilT%    +64.1 +53.1 +43.8 +35.2 +29.7 +18.8 +10.2  +9.4  +5.5  +0.0

# AirT is the barometric adjustment for air temp(based on ideal gas law)
#Temp C   -30   -20   -10     0    10    20    25    30    40    50    60    70    80    90   100   110   125
AirT%   +24.7 +19.8 +15.2 +11.0  +7.1  +3.4  +1.7  +0.0  -3.2  -6.2

They both stop at 50°C. So in order for the air gap "feature" to work, the function of the air gap should be to keep the sensor within "tunable" range, meaning bellow 50°C. However, air gap or not, a prolonged ride on a hot sommer day in heavy traffic would push the sensor far past it. There will be no difference whether thermal paste is in there or not.

 

I say that "air gap" or better "elongated receptacle" is there to protect the sensors plastic parts from being excessively "heath-cycled" at temperatures exceeding it's operating range. Can head temperature go beyond 150°C? I'd say yes, but have no measurement to confirm. Anyone? Brake-rotor-temp-measurers? Could you point one of your rays towards the cylinder head after a ride? WTS05 is a water temperature sensor with operating range up to 125°C. I can imagine that Luigi tried to protect the sensor by placing it as far from the hot cyl head as possible. And being Luigi, he used even more temp. sensitive plastic than the sensor itself is built of. Hence the breakage + customer delight.

 

On the other hand, looking at the OilT and AirT lines, could it be that Luigi just plugged the sensors in wrong way around?

[raz]

Unfortunately you can't use Cliff's MyECU maps for drawing conclusions about how Guzzi developed the stock V11 sensor & map, regardless of how much snow is outside your window

 

Someone, probably Dave, posted screenshots from Tuneboy somewhere long ago on this very forum, one showing an oil temp map (called Engine Temp Trim in Tuneboy) that keep going negative, and ends with -18.8% at 125°C. I believe it was said to be the stock map. I'm not bored enough to try finding it but I do have copies of the screenshots, dated dec 2007.

[Guzzi2Go]

Well, there you go. That's the answer.

[dlaing]

Unfortunately you can't use Cliff's MyECU maps for drawing conclusions about how Guzzi developed the stock V11 sensor & map, regardless of how much snow is outside your window

 

Someone, probably Dave, posted screenshots from Tuneboy somewhere long ago on this very forum, one showing an oil temp map (called Engine Temp Trim in Tuneboy) that keep going negative, and ends with -18.8% at 125°C. I believe it was said to be the stock map. I'm not bored enough to try finding it but I do have copies of the screenshots, dated dec 2007.

I got bored enough...

http://www.v11lemans.com/forums/index.php?...st&p=154689

Also, I updated that post to include MGS01 that does not need to meet emissions, and the 2002 V11, both compared with the 2000 model.

What the heck, I'll post it here, too.

From top to bottom:

MGS01

2002

2000

I don't know whether the MGS01 and the 2002 are modified or not, but I am guessing the temperature maps are stock.

[Skeeve]

From top to bottom:

MGS01

2002

2000

I don't know whether the MGS01 and the 2002 are modified or not, but I am guessing the temperature maps are stock.

 

Whereupon it's discovered that the MGS01 doesn't get any of the "ridiculously lean at high temps" problem seen in the bikes required to meet emissions specs... at least, that's how I interpret the negative numbers seen for the 89C & up temps. Someone correct me if I'm reading that wrong? Either way, it's kind of ridiculous that the map keeps decreasing fuel once the motor is up to temp: shouldn't this be an asymptotic progression, with the correction tending to zero [a la the MGS map] once the temp is up to some empirical "ideal"?

 

Of course, this is only one trim table interacting w/ the base map; the other trims interacting simultaneously may negate that concern. Neverrr miiiiind...

[dlaing]

Whereupon it's discovered that the MGS01 doesn't get any of the "ridiculously lean at high temps" problem seen in the bikes required to meet emissions specs... at least, that's how I interpret the negative numbers seen for the 89C & up temps. Someone correct me if I'm reading that wrong? Either way, it's kind of ridiculous that the map keeps decreasing fuel once the motor is up to temp: shouldn't this be an asymptotic progression, with the correction tending to zero [a la the MGS map] once the temp is up to some empirical "ideal"?

 

Of course, this is only one trim table interacting w/ the base map; the other trims interacting simultaneously may negate that concern. Neverrr miiiiind...

I agree with the first paragraph, but I don't understand how the other maps would negate that concern.

Without an O2 sensor the only other map that could get close to negating is the air temp map

but it looks more like it would aggravate the situation.

[mike wilson]

Evidently, it was determined that a direct read off the sensor (full thermal connection) was even worse according to the Luigi's, otherwise they'd have produced them this way.

 

I don't see that you have any evidence for that assertion. It, equally possibly, may have just not been tried. MG could be installing the sensor as per manufacturer's instructions.

[GuzziMoto]

There seems to be a few who think that everything Guzzi does is purposeful and for the best. I do not believe that to be the case. Many things they (and other manufacturers) do is because it is cheaper/easier or because they don't put the time into it to figure out what the best way to do it would be (it costs money to R&D it). The fact that the temp sensor came a certain way does not mean that is the ideal way, and the fact that the injection was set up with the temp sensor that way does not mean it was optimized for it. The injection is set up to pass emissions first and foremost. Making it run acceptably is somewhere down the list. While you may be able to make your bike run better by fudging the temp sensor or the TPS, neither is the right way to do it and will not work as well as adjusting the injection to match what is really going on. And the more accurate your sensors are reading, the better you can set up the injection to run.

[guzzimeister]

Hi Nige

 

yup your symptoms are right for a duff engine oil temp sensor OR a faulty lead to it. Mate of mine had identical problem on a Cali 1100I. Quite rare but not unknown, mate's bike had 116k miles before it went........ bloody Guzzi rubbish

 

Jon

 

after months of perfect running, my v11 rm started acting wierd; best described as feeling liek the choke was permanantly on. Plugs black as soot, rough running but under full throttle goes like a cut snake, wont idle.

 

new plugs, new caps, no difference.

 

by all accounts ive been advised this is most likely to be a problem with the engine/oil tem sensor located on the rear of the rh head.

 

I followed the manuals instructions (put a spanner on it and take it out and teh sensor came out just fine. Did same to the "oil temp sensor stand off" and "snap" it breaks into peices. WARNING; these are brittle plastic and easily broken.

 

Thansk to lots of help i found replacements and will fit them tonight along with some dialetric grease to ensure the senor is getting good conduction of heat and thus, the right message to the ECU.

 

Questions:

1 I was told ametal/brass replacement was available but the local guzzi distrubutor wasnt aware of one

2 Anyone explain to me how the hell you are supposed to screw the plastic stand off back into the head with decent tension and NOT breaking it?

3 Anyone else had a similar experience with poor running and this being teh solution?

 

thanks !

 

nigev11

[Greg Field]

Hang in there another day. Dr. J is feeling under the weather. I'll be calling him again tomorrow and should have your answer.

[pete roper]

I remain somewhat baffled by Ratch's 'Bouble Blind' argument.

 

The reason I have taken to packing the temperature sensor is quite simply that my tool for reading the live data, (The Axone.) tells me that the information that the ECU is recieving from the sensor is manifestly wrong. Manifestly and consistently wrong, in many cases. Surely if you take the 'Double Blind' argument you could add a 'Triple Blind' in getting the tool to compensate for the compensation caused by the inaccuracy of the signal sent by the sender???

 

Look, I'm not saying I'm right. Simply that it makes sense to me to believe that the tool is supposed to tell me what is actually happening.

 

 

Pete