engine oil temp sensor

[Dan M]

Such have been among my thoughts also, Dan. Seems to me the brass holder and OE holder were both intentionally designed with a considerable air gap (.25") for a specific intent and purpose that we've been directly thwarting here with heat conducting materials.

 

The fins on the brass holder, unlike the OE holder, were clearly designed to dump heat. This means it flows heat through it -- not simply into it, like the OE plastic holder, which is more of a tiny dead-end for heat flow. Constant heat flow through the brass holder would seem to more rapidly (and potentially more accurately) respond to the changing delta in temps betweeen the head and ambient. But that's just me.

 

The part of this that doesn't add up is with the plastic holder, what is being sensed is the air temp in the gap under the sensor. It is not however an air temp sensor. The fact that it is brass tells me that it must be in contact with whatever it is sensing. The fact that both the plastic and brass holders are sealed to outside air means the air temp inside will not change very rapidly. I'm thinking their intent was to ballpark the head temp with no sudden changes. The main focus being mixture on cold start up. It would be interesting to see how it is mapped from the factory to find out how much weight that sensor carries at different values.

 

edit: Last winter I had my tank off and prompted by the writings here I gave the sensor a look. Mine was finger tight. Without thinking it through, I followed the wisdom here and packed the cavity with anti-seize to take up the air gap. It made perfect sense. This past summer I had some fueling issues and wasted a bit of time trying to get things to where I wanted them. (never giving the temp sensor another thought) Now I'm thinking that I may want to restore the air gap and see what happens. Perhaps this was reverse engineering. Maybe they found it was too sensitive and factored in an air gap. It is not too far fetched, just like putting on an adjustable pressure regulator then not hooking it up. We've beat that one to death but summed up that it too should be left alone.

 

 

Reverse engineering the intent of long-retired and gone Italian engineers who operated at the ragged limits of sporadic, puny, and non-existent budgets under dubious "continuous transition management" (d'you reckon they were at least smart enough to demand payment in advance for services rendered? ) in a lake resort at the foot o' the mighty Dolomites -- ain't that wot a Guzzi Winter is for, after all?

 

More futzing later today.

 

Say Dan and Henry -- Speakin' o' heat flow -- I just gotta ask. Wot's the local spin on the ever-expanding noxious cloud emanating from the Blago-ObamaNation stink bomb? Will this eventually be doctored up enough by The Chicago Tribune, et al to pass as simply more corrupt Chicago Daley/Blago/Obama Machine politics as usual, or d'you think the national focus at the time of the inauguration-coronation actually suffered enough collateral damage from Blago-splatter that ol' Hot Rod will have to be strung up to take the heat off The Messiah?

 

Enquiring minds. . . (well, you know). . .

 

Just a quick thought on "The Rod"

He is out of his mind. The more that comes out, the more clear it is. I think Obama is insulated from his lunacy. Daily is pretty slick, powerful and gets his job done. (Chicago has never been a nicer place to be) He is also insulated from this issue. All of it will be spun both ways depending on who's doing the spinning.

In the end it will fall on Rod. His lawyers are fleeing as we speak.

 

Back to motorcycles now.

[Guest ratchethack]

The part of this that doesn't add up is with the plastic holder, what is being sensed is the air temp in the gap under the sensor. It is not however an air temp sensor. The fact that it is brass tells me that it must be in contact with whatever it is sensing. The fact that both the plastic and brass holders are sealed to outside air means the air temp inside will not change very rapidly. I'm thinking their intent was to ballpark the head temp with no sudden changes. The main focus being mixture on cold start up. It would be interesting to see how it is mapped from the factory to find out how much weight that sensor carries at different values.

Roger that, Dan.

 

With the brass holder, seems to me most of the heat to the sensor flows directly into it via the path of least resistance, that being through direct metal-to-metal contact through the threads of the holder into the sensor, as you've noted. I'd tend to think this might be "all" the heat flow that matters here, but SIGNIFICANT additional radiant heat must flow directly across the gap. I suggest that this must be significant, otherwise why spec a ~6 mm air gap, rather than something like 1 or 2 mm??

 

CORRECTION: I just corrected my previous post after taking a measurement. As a considerable design departure from the brass holder, the OE plastic holder is evidently designed to seat the sensor tip directly in contact with the flat bottom of the hole in the sensor.

 

. . .Now I'm thinking that I may want to restore the air gap and see what happens. Perhaps this was reverse engineering. Maybe they found it was too sensitive and factored in an air gap. It is not too far fetched, just like putting on an adjustable pressure regulator then not hooking it up. We've beat that one to death but summed up that it too should be left alone.

My sentiments approximately, if not substantially. Both OE map and (in my case) PC III map were created with the OE plastic sensor.

 

I'll be trial-and-erroring the plastic vs. brass holder with measured air gaps and will simply pick wotever runs best.

 

I just counter-bored the lead slug in my brass sensor to provide a .1" air gap.

 

Will install and will advise (Part II).

 

EDIT: Not much of a change between direct metal-to-metal "fully seated" sensor in the brass holder and same with .1" air gap. Still unacceptable with much the same symptoms.

 

Will drill to a .2", air gap, road test, and will advise (Part III).

[Dan M]

I just counter-bored the lead slug in my brass sensor to provide a .1" air gap.

 

Will install and will advise (Part II).

 

EDIT: Not much of a change between direct metal-to-metal "fully seated" sensor in the brass holder and same with .1" air gap. Still unacceptable with much the same symptoms.

 

Will drill to a .2", air gap, road test, and will advise (Part III).

 

Sonofabitch. I wish I could play too. I love this stuff.

It's 11F here with about 10" of snow cover. The garage is heated but not big enough to ride around in.

 

Edit: it would be interesting to know how fueling would react if the brass holder had some some small holes for air circulation.

You don't have 2 do you?

[dlaing]

The alternative is to remap the ECU from the following

http://img123.imageshack.us/img123/8966/tb...ginetempur5.gif

I took a look at some of the other maps available from Tuneboy and it is clear that later models (2002+) had much milder engine AND air temperature compensation.

The MGS01 was especially mild with zeroes in from something like 50C to Maximum

I'll be trying a Scura map (since I have Scura mufflers (and Ohlins that really effect fuel mixture requirements (JK)))

EDIT here are the maps, from top to bottom, MGS01, 2002 US V11, 2000 US V11.

[dlaing]

Will drill to a .2", air gap, road test, and will advise (Part III).

You might also wanna try teflon tape on sensor threads, which will insulate a little and increase the air gap a little.

But yes it will side track the air gap theory, but not the overly hot theory.

[Guest ratchethack]

Sonofabitch. I wish I could play too. I love this stuff.

It's 11F here with about 10" of snow cover. The garage is heated but not big enough to ride around in.

 

Edit: it would be interesting to know how fueling would react if the brass holder had some some small holes for air circulation.

You don't have 2 do you?

I weathered 24 winters on the other side of Lake Michigan from you, my friend. I sympathize.

 

Holes in the brass holder might be something to try unless I hit some kinda "sweet spot" here. Not lookin' any too likely at this point. No, I only have one of each, plastic and brass.

 

With a .2" air gap in the brass holder, the symptoms are again much the same. Again, the symptoms are: ". . .abominable. It wouldn't idle when fully warm, missing and coughing at low RPM and off-idle transitions in traffic something fierce. . . .it ran fine at normal operating RPMs at speed, [and] was just about unrideable in town."

 

NEXT STEP: I'm taking all the lead out of the brass holder to test it this way. Until I manage this, the plastic one's going back in just so I can experience riding it again without the punishment. . . .

 

Will advise (Part IV).

[dlaing]

snip

In any event, my bike is continuing to run well with the improved sensor-head contact.

FWIW Tony aka rologuzzi has a 2003.

I started getting idle problems after switching to the brass sensor and have suspected that it gets too hot.

The most consistent symptoms are missing at slow speeds and if I ride on the freeway at 70+MPH take an off ramp to a stop light and stall.

I am betting that 1999-2001 V11s don't do well with less air space, or brass sensors conducting too much heat.

Looking forward to Ratchet's results.

[Bruce Reader]

G'day everyone.

 

Do we have any data on the bikes that originally had the brass temp sensor holders in regard to fuel maps and idiling performanece ?

 

Id like to get the brass temp sensor correct as my plastic one was missing a 10mm shard out of it before i replaced it. Even if the gap is needed the plastic piece is crap.

 

Cheers

 

Bruce

[pete roper]

Regardless of whether the temperature sensor is supposed to have an air gap or not the tool tells you that the ECU is getting an inaccurate reding.

 

One can only assume that it is supposed to get a reasonably accurate reading otherwise what would be the point of it at all?

 

While the difference in performance achieved by packing the sensor may be so small as to be pretty much un-noticeable it will tend to have a profound effect on fuel consumption, especially in cold weather.

 

YOMV.

 

Pete

[Guest ratchethack]

Even if the gap is needed the plastic piece is crap.

Bruce, I hope you won't be offended if suggest another point of view?

 

For those who've attempted to remove the plastic holder with a wrench by cranking on it as if it were made of steel, and instantly broke it in the process, there will no doubt be a tremendous temptation and horrific motivation to conclude that "it's a piece of crap". O' course, once it's broken, it's not much more value to anyone than something you'd routinely flush down the Grand Oubliette as quickly as possible, just to get it out of odor detection range. Understood.

 

Per posts above, I'm just suggesting that wot may be a "piece o' crap" to you, with a little knowledge and care, may be something far more valuable than the only known commercial alternative to someone else. I've managed to have mine out and back in a half dozen times without breaking it, and at this point it seems to work far better than the brass one in terms of doing what it was designed to do.

 

But as always, that's just me, and YMMV.

[dlaing]

snip

G'day Bruce,

As I understand it the V1100Sporti that shipped with the brass holder, had pretty bad fuel injection problems. If you didn't have a Creedon Chip or similar they often did not run well.

Maybe some of the problem was the brass temp sensor?????

I have had the plastic holder on order for several years now.

If I don't get my issue sorted at the map, then I will be CAREFULLY installing it, if it ever arrives.

It did not take much torque to break the holder. It is about as strong as a 2 or 3 mm bolt.

From that perspective it is certainly crap, but from the perspective of feedback to the ECU, it may be better at higher temperatures, but as Pete pointed out there is an issue of V11s running too rich when warming up, that is helped by conducting across the gap.

I think the answer is in the mapping, but even if optimized, the mapping can't compensate for all conditions such as rain cooling the sensor.

[Bruce Reader]

Bruce, I hope you won't be offended if suggest another point of view?

 

For those who've attempted to remove the plastic holder with a wrench by cranking on it as if it were made of steel, and instantly broke it in the process, there will no doubt be a tremendous temptation and horrific motivation to conclude that "it's a piece of crap". O' course, once it's broken, it's not much more value to anyone than something you'd routinely flush down the Grand Oubliette as quickly as possible, just to get it out of odor detection range. Understood.

 

Per posts above, I'm just suggesting that wot may be a "piece o' crap" to you, with a little knowledge and care, may be something far more valuable than the only known commercial alternative to someone else.

 

But as always, that's just me, and YMMV.

 

Its crap because it fell to bits insitu ! Therefore having one hell of an air gap. As you said once broken its probably of little value.

[Guest ratchethack]

I b'lieve this fairly cries out for a rousin' revue o' th' famous Dead Parrot skit:

 

 

"Lovely plumage, innit?"

 

"It's plumage is entirely beside the point! It's bleedin' demised!"

 

[raz]

As I understand it the V1100Sporti that shipped with the brass holder, had pretty bad fuel injection problems. If you didn't have a Creedon Chip or similar they often did not run well.

I think the V10's had the brass sensor, and Cali, but not the 1100 Sporti. It has a, theoretically, even worse solution than your air gap: The sensor sits high in the LH valve cover, with a bare NTC inside that sometimes happens to get some oil slushed upon it. It has plastic housing.

 

On the other hand I've never had any problems that had me suspecting that sensor. But I've been running aftermarket chips (and now a MyECU) ever since I bought it.

 

Guzzi call it "oil temp sensor", not cylinder head temp sensor. That goes for both Sporti and V11. With our primitive EFI systems I think air temp is much more critical than oil temp for getting the mixture right. Oil temp is mostly needed for some boost while the engine is cold.

 

Then again you may have OEM temperature maps or experiences that contradict this. I have no idea why. It's a Guzzi

 

OTOH, if they really meant it to be just an oil temp sensor... why oh why did they not just mount a fool proof oil temp sensor in the sump instead of trying to morph it with a CHT sensor?

 

I guess what we got is a mix of different ideas that Guzzi tried, that ended up in a mess. The parts involved are what happened to be available from their suppliers (In the Sporti case, the oil temp sensor is exactly identical to the air temp sensor <_ i won buy the theory that guzzi actually made air gap on purpose. no way src="%7B___base_url___%7D/uploads/emoticons/default_laugh.png" alt=":lol:">

[pete roper]

I won't buy the theory that Guzzi actually made that 1/10" air gap on purpose. No way

 

 

Me neither. They bought a job lot of sensors designed to be stuck in a water jacket or radiator because it was cheaper than doing it properly.

 

Pete