help 2001 s4, apparently no front cylinder temp sensor!

[cw]

Help dumb question time, I have a 2001 s4, it has a temperature warning light. Everyone says there are two temperature sensors, front cylinder drives the warning light, rear drives the ECU and then onto the fans.
I have been all over the top radiator hose pipe, it goes Radiator, T piece( no attachments completely plain), rear cylinder inlet(with a temp sensor screwed in it.) The bottom of the T drops straight down to the front cylinder inlet, which has a cast lug but not drilled out and no sensor!
The lower rad pipe goes straight to the pump housing no sensor there either.
Have pictures if I can figure out how to load them.
Basically want to fit a temp gauge, can get a 25mm alloy adapter that looks like it would fit in the top rad pipe, but would rather re-use the front sensor hole to drive the gauge if I could find the dam thing!!

[LowThudd]

can't help with the sensor, but photobucket.com will help you with picture hosting. And you can load them from there. http://www.ducatimonsterforum.org/index.php?topic=109.0

[Speeddog]

This is what it looks like on an '02 S4:

[cw]

My version of that union is a plain right angle into the head with no sensor, I am thinking the bolt spacing and O ring will be the same so I think I will look for an 02 s4 union on ebay, thank you both for the help.

[cw]

Can see a few of the rear cylinder unions with sensor mount on Ebay, does anyone now if the O ring and triangle bolt spacing is the same as the front cylinder, would make a neat solution if it was a bolt on swap.

[Speeddog]

Can see a few of the rear cylinder unions with sensor mount on Ebay, does anyone now if the O ring and triangle bolt spacing is the same as the front cylinder, would make a neat solution if it was a bolt on swap.

Yes, O-ring and bolt spacing is the same.

In fact, the heads are the same.

[cw]

thank you, will take a closer look at my rear one and see if it will fit in the space/ match up to the pipe work or maybe with a small mod fit in etc, much better than cutting an adapter into the top hose.

[Speeddog]

Don't have the bike at hand, but I don't think the rear one will work.

It's part# 81411191A.
If you're feeling flush, get one new, but they're north of $100. 
Double check part# before you buy...

AFAIK, a cooperative dealer parts guy can tell you what other Ducatis used it, so you can scour E-bay or the like.

[cw]

Hi finally got all the bits together and added the temp gauge to the 2001 s4. I used a rear cylinder water union with an m12 to 1/8th adaptor for the gauge sender bolted to the front cylinder. Its a bit longer so shortened the bottom hose from thermostat and  at a slightly different forward angle so the 3/4" hose to the back cylinder need replacing with slightly longer piece.
For wiring, I disconnected battery, removed the instrument unit, stripped it down, added wires into the live,earth and back light circuits and made those into a short fly lead with bullet connectors out of the original speedo cable hole. Wiring diagram in owner hand book is spot on.
Made up an ally flat bracket to fit the gauge pod (and an angled block) to  right side of instruments using fly screen bracket bolt.

Striped down rest of  cooling system and flushed, replaced coolant with VW/Audi G+ spec non silicon. Added a home made stone grill to rad.
Also replaced my ECU temp sender with an intermotor 5556 (UK part) and now my fan's actually kick in when I let it heat up on the stand and I know what temp my coolant is at, probably +-5%ish, so  much better than the idiot light, spent about £65 all in, which is about £45 less than the local stealer wanted for the OEM ECU sender !
All bits were ebay sourced apart from 3/4 hose which was a quick trip to local car shop on a Saturday afternoon, £2.50 for  500mm. note old fitting soaked in boiling water with new hose made fitting new hose much easier to very fiddly rear cylinder, not much wiggle room in there.

[Speeddog]

The ECU uses the temp sensor to trim fuel mixture, as well as to decide when to turn the fans on.

So the different sensor may not give it the right data.

[cw]

Agreed, did a lot of research into the ECU sensor cold map/hot map switch over point etc, you guys seem to go for a napa part that's not in UK. the standard WTS09/05 sensor you can get the down loaded pdf spec for, plus all the alternate part numbers, they are standard car ECU management items, e.g. nothing Ducati specific. This is an experiment but so far I have fans at the right temp and I never had before so hopefully this is the way to go.

[Speeddog]

Cool, you did the groundwork. 

Fans weren't turning on at all, or too high, or?

[cw]

nothing at all! let it get really hot nothing happen so quit before I broke something , so started looking at whats wrong threads found loads on duff temp sensors, doggy fans, wiring, blocked rads, then started to think about temp gauges so I knew what was going on with the  coolant. Got to keep budget tight, so any mods have to be ebay/alternate parts, safety  first, alternative maybe but no bodging. Now know in UK on a hot day 24C, normal running through the surrey hills it stays around 65 to 70c so never comes off the cold map, only see high temps if I let it idle a bit when I pull in or  goes up a bit more if playing chase . Had it all apart  total clean inside, only crap I saw was slight discoloured to water when I used compressor driven paraffin gun as a hot water jet wash on the rubber pipe work, rad, blocks, pump all ran clean after a few goes (I keep the old coolant/flush in small plastic milk bottles and compare to last one till I get clean water out).  Found a thread that talked about rad being sized to run at about 80c in 30c temps, so never going to get there in UK, more likely to need floats...

What I am total unsure on is do I want to think about masking the rad to get it to run on the hot map at about 80c, its run almost 10k miles as is, had the DP ECU/dragon air filter/ air box chop/Termi's on it since new (now have DB killers in), runs well, starts first go every time,  anyone got any thoughts on this ? I suspect most US ones run normally a lot hotter.
Apart from knowing I am not on the hot map I think it runs really well , also dropped the gearing, 14 tooth on the front, massive improvement for £18! which should marginally push up the heat maybe?
Also  stopped the death rattle clutch, sorry to the purists, but really don't think it should be hammering itself into an early grave, sounded like a tin can full of loose bolts spinning around, could not hear rest of engine bike came with a new clutch pack fitted which when disassembled was still perfect on the tabs, old one was in a DP box.
Used to have black/gold Darmah back in the late 70s/early 80's that never made that noise

[Speeddog]

I've found my S4 runs about 100 degF above ambient when it's rolling at any decent speed.

So it has to be stinking hot out and some slow stop-and-go traffic to get the fans on.
I don't enjoy that riding at all, so it doesn't happen much, even here ( It'll be ~100degF for the next few days  )

You could tape off some of the rad to see if it feels like it runs better when it's warmer.
I'd tape in an area where it's not blocking the fans, so it'll run hotter but not compromise the ability of the fans to cool it.

I've found the bike seems to run a bit unhappy when it's near 200 degF.
Whether that's engine temp or just due to ambient air at ~100 degF (and fuel same or hotter), don't know.

Mine seems to run best at about 170 degF or so.

I've not spent much time running with OEM fueling, added a power commander pretty early, then FIM U59 ECU when original MM box died, Then Microtec when U59 went duff.

[cw]

thanks for the info, I'll plug that into the calculator, definitely not going to get those sort of temps over here!