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engine oil temp sensor


nigev11

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After just playing with one to find out its not the problem The "engine oil temp sensor" which is acutally the head temp sensor and has little to !@#$ all to do with the oil temp. What makes me say that I have a bike that has an additional temp sensor in the oil cooler and the reading out of that are radically different to the head temp sensor. Is a NTC (negative temperture coefficent) themocouple with a range of -40 to 170 ish degrees celcius. NTC means as the temp goes up the resitance goes down resitance at 10 degrees is around 3.7K ohm and at 80 degrees is 0.37kohm. Buy rights you should be able to bung a 10cent resitor in there and run home on that if it fails. The sensor does not earth through the cases oil preasure switch style but has a return line to the ECU. Hope this helps NB all temps are celcius/metric.

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Docc, from the title of this thread, there may be some confusion about wot sensor's wot here. :huh:

 

The engine temp sensor is screwed directly into the inboard-rear of the right-hand side cylinder head.

 

There are 2 sensors in front of the left cylinder set in the engine case behind the cam chain case. The lower one is fixed by two socket-head screws. It's the timing sensor. The top sensor screws in. It's the oil pressure sensor. The OPS doesn't require any attention unless/until it fails to switch contact to ground at some ridiculously low pressure of a few lbs.

 

 

Thanks. I swear I had this figured out at one time. :blush: The time has come to re-immerse myself in the sport in preparation for the South'n Spine Raid. Now back to that fork thread . . . :luigi:

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After just playing with one to find out its not the problem The "engine oil temp sensor" which is acutally the head temp sensor and has little to !@#$ all to do with the oil temp. What makes me say that I have a bike that has an additional temp sensor in the oil cooler and the reading out of that are radically different to the head temp sensor. Is a NTC (negative temperture coefficent) themocouple with a range of -40 to 170 ish degrees celcius. NTC means as the temp goes up the resitance goes down resitance at 10 degrees is around 3.7K ohm and at 80 degrees is 0.37kohm. Buy rights you should be able to bung a 10cent resitor in there and run home on that if it fails. The sensor does not earth through the cases oil preasure switch style but has a return line to the ECU. Hope this helps NB all temps are celcius/metric.

 

Thanks for the clarification Murray. OK, so the resistance falls with an increase in temperature rather than rising but the principle remains the same. So what is the problem with your bike and have you found a cure? Nige has been having a hell opf a time trying to get his Rosso working and any identified problems can be good grist for the mill.

 

On earlier bikes where the temperature sensor was in the rocker cover I suppose that it could, vaguely, be described as an oil temperature sensor as it did get splashed with oil :grin: . As you point out though the one that screws into the back of the head is nowhere near any oil, (Or it shouldn't be!) so the refference is spurious.

 

Pete

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Who knows? I might be completely, brain-dead wrong, (Although I think any manual will tell you otherwise, they even tell you how to test the thermistor the 'Old Way' with a kettle and a mercury thermometer :oldgit: ) but I'll wager a barn full of bloated Bulgarian bibliographers that while a playing up ETS might not be the only problem the fact that it's staring him in the face like an excited peadophile it is certainly worth addressing and can't be lumped in as 'Bullshit'.

 

Gah! That sort of shit really hacks me off. I left the rally at 7.00AM this morning and just got back to Bungendore. 1178 Kms in 13.45. Not bad for an old git on a Griso with a wogged pipe! :grin:

Pete

 

 

Pete has it exactly right. (and I love it when people ask a question of someone and then tell them they are wrong. "So don't ask me next time")

 

Poor contact between the thermistor and the head is very possible. I've seen thermistors (not moto guzzi mind you but they all work on the same principal) have an open section at a specific temp range. Could be accurate cold but open at higher temp, fooling the ecu into thinking it is very cold, hence the extra fuel. It is best to back probe the connecter, run some wires to where you can get to them with the tank in place and check the resistance at various temps to make sure it is accurate throughout the range.

:2c:

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After just playing with one to find out its not the problem The "engine oil temp sensor" which is acutally the head temp sensor and has little to !@#$ all to do with the oil temp. What makes me say that I have a bike that has an additional temp sensor in the oil cooler and the reading out of that are radically different to the head temp sensor. Is a NTC (negative temperture coefficent) themocouple with a range of -40 to 170 ish degrees celcius. NTC means as the temp goes up the resitance goes down resitance at 10 degrees is around 3.7K ohm and at 80 degrees is 0.37kohm. Buy rights you should be able to bung a 10cent resitor in there and run home on that if it fails. The sensor does not earth through the cases oil preasure switch style but has a return line to the ECU. Hope this helps NB all temps are celcius/metric.

 

Murray, the one in front on your bike is only for the display, and does nothing to the ecu.

The air temperature sensor and the head temp sensor should have almost the same resistance when bike is cold.

The name oil temperture sensor is used from the beginning by guzzi, i suppose because the first electrical drawings from marelli were for a car. For the ecu, the oil temp isn't interesting, but the head is, that's where it sends its mixture.

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Thanks for the confirmation. It's nice to feel vindicated.

 

I make no claims to *knowing it all*. In fact I'm pretty much a newbie when it comes to FI and I spend a LOT of time listening and learning from others about not only potential problems but also how the whole system works. Perhaps the fact that I am willing to say "I don't know" makes me some sort of charlatan? I tend to think the opposite though <_>

 

Pete

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Hi all,

 

It should be noted that there are 2 temperature sensors in the system, air temp and engine/oil temp. Both sensors are identical ( same NTC thermistor ). The sensor itself is unlikely to fail. What is most likely is that due to corrosion or wire break, the effective resistance will increase ( colder ) or be infinite ( bloody cold ).

 

Failure of either sensor is likely to cause the over rich mixture.

 

The best check to make is to check the resistance of the sensor from the ECU connector.

If I'm not mistaken the sensors come in on pins 4 and 18 of the 15M connector - http://www.cajinnovations.com/MyECU/pics/My15MMkIII_PCB.png

Measure resistance to ground on pins 22,23 or 24. These are usually connected together in the ECU but with the connector off, you will need to see which of these to check. Try Carl's schematics.

 

The resistance to expect is here - http://www.cajinnovations.com/MyECU/temperature.htm but the easest check is for a cold engine both the sensors should read the same

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Cliff,

have you considered using the cylinder head temp sensor to keep the engine from overheating, possibly by enrichening if it gets too hot??? Or better retarding the ignition to reduce the temperature??

Would that be a bad idea?

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Guest ratchethack

Cliff,

have you considered using the cylinder head temp sensor to keep the engine from overheating, possibly by enrichening if it gets too hot??? Or better retarding the ignition to reduce the temperature??

Would that be a bad idea?

Dave, I'm not "having a go" -- honest. -_- But I don't recall ever hearing of an actual "overheating" situation with a V-11. Vapor lock, yes. But not overheating. Vapor lock doesn't mean overheating. Not only are these motors "over-finned" to the point of being "over-cooled" in cool and cold weather (I b'lieve this is actually more of a real concern), but with a thermo-regulated oil cooler, IMHO this just about eliminates anything close to a possibility of over-heating under any conditions -- bar stuck in gridlocked traffic in some places in late summer. With lane-splitting being legal here in CA, even THIS ain't a prob. :thumbsup:

 

I've been flat-out on the Mojave destert in up to 120F heat for hours on end without a sign of the engine over-heating. I b'lieve for the most part, it's never a concern with a V-11.

 

But that's just me. :huh2:

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Dave, I'm not "having a go" -- honest. -_- But I don't recall ever hearing of an actual "overheating" situation with a V-11. Vapor lock, yes. But not overheating. Vapor lock doesn't mean overheating. Not only are these motors "over-finned" to the point of being "over-cooled" in cool and cold weather (I b'lieve this is actually more of a real concern), but with a thermo-regulated oil cooler, IMHO this just about eliminates anything close to a possibility of over-heating under any conditions -- bar stuck in gridlocked traffic in some places in late summer. With lane-splitting being legal here in CA, even THIS ain't a prob. :thumbsup:

 

I've been flat-out on the Mojave destert in up to 120F heat for hours on end without a sign of the engine over-heating. I b'lieve for the most part, it's never a concern with a V-11.

 

But that's just me. :huh2:

Excellent points.

I too have never been in a situation where overheating threatened the bike, although once while balancing the TBs the pipes started to glow.

My fear of overheating would occur if I dare tried to optimize the fueling to improve fuel efficiency.

Potentially increasing leaness or ignition advance to the point where one might get an extra 5 or10 MPG would push the engine temperature up to the point where hours of lane splitting across LA (at a safe pace) could damage the engine.

I intend to data log with sensor data of WBO2, RPM, Throttle Position, and engine temperature. Exhaust Gas Temperature would be more meaningful, but it is a lot easier for me to log engine or air temperature.

I have been procrastinating on logging data for two years :homer:

But my data cable for my LM1 from Innovate arrived today!!!

($12.95 plus $15.95 shipping from Innovate in Irvine, CA to SD, CA, for a simple serial cable that I probably could have got for $5...It would not bug me so much if the online form disclosed the shipping price before the order was complete <_>

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($12.95 plus $15.95 shipping from Innovate in Irvine, CA to SD, CA, for a simple serial cable that I probably could have got for $5...It would not bug me so much if the online form disclosed the shipping price before the order was complete <_>

 

That bites. Here, let me rub salt in that wound for you: I work in Irvine & would have been happy to "will call" it for you & then meet you in San Clemente or Oceanside or something to hand it off. There, does that sting any less now? :cheese:

 

I hate it when companies use their shipping dept. as a profit ctr... :bbblll:

 

:mg:

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Errr? Guys. Unless Im seriously mistaken the ETS is a simple thermistor. It doesn't ground to *earth* at all. What it does is increse the resistance in the body of the unit as it heats up. This is the reason it has more than one wire going into it :homer: . It's not like the oil pressure switch for example which is a simple 'Off/On'.

 

In my experience what *Appears* to be the problem is that the tip of the sensor doesn't make contact with the *bit* in the mount that screws into the head. This means that there will be an air gap and air is a really good insulator so even in the *secured* environment the temperature differential will be enough to cause problems.

 

It's interesting this has come up as I was at a rally this weekend and took my Axone tool up with me purely to show anyone who was interested what it could tell you about your bike. I plugged it in to several bikes, both V11's and Calis, and I think that most of the people who were there (Morris Sod was one of 'em.) would agree that the temperature reading being sent to the computer was CONSISTENTLY considerably lower than the actual head temperature. In some cases by many tens of degrees centigrade.

 

Now just call me 'Mr. Stupid', (And the local Guzzi Guru told one owner that what I had said was 'Bullshit') but if the ECU is being told that the engine is cold it's going to deliver more fuel to it? No? If you aren't going to have a variable delivery system why bother with an ETS? Why not just have a 3 position 'Toggle switch' that will send a choice of one of three signals to the ECU, one for 'Cold', One for 'Hot', and one for 'F#cked if I know?' somewhere in the middle? You'd always be able to get the motor running, it is after all what a conventional *Choke* on a carb does, innit? So working on the principle that the ECU is getting a false temperature reading it will tend to consistently over fuel. This will lead to poor fuel ecconomy and, oddly enough. a tendency for the engine to foul plugs and run like a munter in traffic. STRANGELY ENOUGH exactly the symptoms that the owner who the 'Guru' told my theory is 'Bullshit' is suffering from. Did it make me a bit cranky to a.) be treated like a c@nt for offering to try and help someone? Yes, a bit, even though the object concerned was pissed off his face and looking to be beligerent. b.) Be labeled as a BS artist by someone who couldn't be bothered to approach me and even discuss it, (Hey! I might of LEARNED something, but all this stuff has to be kept *secret*, eh? :vomit: ). Yeah? Well @#!#$# 'em. It'll be a cold day in hell before I attend that rally again. (No reflection on Morris or the 'Nevilles' in this, they seemed genuinely interested, and all I was trying to do was show people something they wouldn't usually see. :huh2: )
Who knows? I might be completely, brain-dead wrong, (Although I think any manual will tell you otherwise, they even tell you how to test the thermistor the 'Old Way' with a kettle and a mercury thermometer :oldgit: ) but I'll wager a barn full of bloated Bulgarian bibliographers that while a playing up ETS might not be the only problem the fact that it's staring him in the face like an excited peadophile it is certainly worth addressing and can't be lumped in as 'Bullshit'.

 

Gah! That sort of shit really hacks me off. I left the rally at 7.00AM this morning and just got back to Bungendore. 1178 Kms in 13.45. Not bad for an old git on a Griso with a wogged pipe! :grin:

 

Pete

Now Pete don't be too sensitive, I totally agree with Gilmore's remarks. The rally is to stretch our bikes legs and talk bullshit to our mates. Information as Mark says is better confined to these pages.

 

However I was very grateful for your timely input about the heat sensor and your diagnostic on my bike albeit short of the TORK tool to do the adjustment. I happened to smell my exhaust pipe whem I got home and could detect a fairly strong wiff of fuel especially in the right pipe. This is obviously contributing to my lousy fuel consumption.

 

Do you carry the plastic sensor cover that is likely to get broke on removal, so that I can have one ready when I redo my heat sensor, or should I try and source more locally.

 

BTW I will be carrying out the TB adjustments as you prescribed once I can get my V Twins mate to set it up.

 

Pete we did listen and the 3 of us you checked our bikes for were more than grateful for your input. Its a pity I couldn't talk to you more but someone else seemed to have the conversation monopolised.

 

Sounds like you had a great trip back all credit to the Griso, eh.

 

How is the best way to put an order in for a sloppage plate, through this site?

 

Any way cheers The Nevilles appreciated it. :bier:

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That bites. Here let me rub salt in that wound for you: I work in Irvine & would have been happy to "will call" it for you & then meet you in San Clemente or Oceanside or something to hand it off. There, does that sting any less now? :cheese:

 

I hate it when companies use their shipping dept. as a profit ctr... :bbblll:

 

:mg:

There was no "will call" option, just a "give us your credit card number and we'll bill you whatever we want for shipping" option. nice. :not:

But thanks for the offer!

I did not know you were in So-Cal. Hope to see you on a group ride :bier:

I am pretty sure I could have gotten the cable at Radio Shack or Fry's Electronics for much less money, but I did not want to take a chance with pin assignment.

The salt on the wound came from the fact that I bought this on eBay and the seller repeatedly "forgot" to ship the cable to me. I gave him so many chances that the opportunity to give him bad eBay marks passed....lesson learned about being too nice :homer:

Probably half my savings from buying second hand on eBay got eaten up by the cable purchase....oh well, it is relatively small money.

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Getting back to the topic of the thread,

 

I've started to focus on this because I think I've got some symptoms of less than accurate sensor operation, per this thread and many previous posts on this.

 

Seems to me the brass holder solves the problem of the broken stock holder, but without something between the thermistor and the base of the recess in the holder, the key operating principle of faulty temp pickup will be the same with both the plastic and brass holder. :huh2:

 

So if the original plastic holder is still intact, wouldn't the best approach be to simply take out the thermistor/sensor and dab in a dollop of thermo-goop and/or solid part to fill in the aforementioned gap and screw it back in, thereby solving the innacurate temp read problem? :huh2:

 

Anyone out there take this approach?

 

Another thing: Would not anti-seize or thermal compound have a tendency to boil off, and/or leak out with thermal cycling over time? Never used anything like a thermal compound before -- it would seem that the stuff would be formulated to resist this, but not knowing a thing about it, I gotta ask.

 

TIA

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