problem's problems. (temp reduction mod question)

[karlos]

sensor is normal closed then - I dont use air con much, so no it wasnt turned on, hope it was just the switch! kind of makes sense if that could be the course- obviously we took all thaht lot out to look at the vacum pipe to solonoid to replace it maybe the reconnection/contacts in plug are not so good. - will keep an eye on - definitely didnt pee out coolant.

[karlos]

sensor would be normally open, so when it gets hot it would make then?

I pulled the plug off the sensor which sits in a rubber electrical grommet next to the handbrake on the driver side, It looked like an ambient sensor similar to one on my car, a plug with a plastic probe.

Removing the connector did not switch the fan on - so I guess that's that Idea out the window, unless there is more than one sensor fron the cab into the engine bay on the drivers side near the hand brake -

seems all a bit strange, have not took it for long enough drive today to get engine warnm enough. I do not understand what or why this happened, seems a bit strange after reconnecting vacum pipes to the correct places.

I will change my hoses and follow the bleed procedure and fit coolant temp gauge, hopefully will have no reoccurance - I dont like unexplained and or intermittant problems.

[haydn callow]

Pull the plug off and short out the contacts with a paper cllp// fan will activate.

[missfixit70]

This thread may help Karlos - http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=29687

[dandywarhol]

Pull the plug off and short out the contacts with a paper cllp// fan will activate.

Not always Haydn - sometimes only the briefest flash with the paperclip is needed to activate the ECU to operate it, bridging it completely doesn't turn it on - seems pretty temperature dependant! Thats why I don't like the idea of modyfying the switch to a manual flicker - the whole plot is ECU controlled.................

[Doone]

Allan doesn't like the idea of a switch, IF affects the ECU operation.

[missfixit70]

All discussed on the link I posted

[karlos]

My appologies simon t - un-plug the ambient temp switch with ignition on after a few sec's the fan does come on!

So I'm just guessing the fan is switched by a relay so with ignition on it would be permantly runing but the ambient sender must either break the earth to relay or live, buy way of a resistance that alters according to temp.

Anyway I couldnt leave it alone so - I drove it for at least 1/2 to 1 hour to get engine warm with a few stop starts to see when or if the the fan would kick in (could not get it to kick in) when I gave up I pulled into petrol station to top up - fan not running - after fillling up putting the ignition on ,waiting for glow plug light to go out, the fan came on for about five sec'c then went off - so I'm guessing as the van stood the rising heat with no cooling air flow, raised the engine bay temp enough, after all the block is like an old cast radiator when stood still.

If I had fired it up quick, or drove the air flow/vacum probably would have stopped the fan coming in, It actually seems quite normal to me -

it's not running temp it seems to be the standing radiating heat. (strange how I left it ticking over prior to stopping at the petrol station after driving round and it didn't fire the fan up, and after leaving the petrol station when the fan had cut in, obviously driving cooled the motor a bit, but I could nt make the fan cut in again?)

The princable sound's right but none of you have expeirenced it, It obviouly involves driving till the engine is at max temp, parking up briefly not giving the engine time to cool then turning the ignition on "fan cuts in" seems very inconsistant though!

I might change the engine bay ambient switch,plug and a bit of the wire in the loom, the sender's plug wire's look as If they have got a bit hot at some point, but cannot be totally open circuit - seems a bit hit and miss , but it does seem to co inside with cab getting warm whilst driving. all though the coolant doesnt over heat in anyway, the temp seems to rise and drop, it will fall even after a long journey with steady driving, but some times the cab does seem to get warm?

Coolant not boiling or disappearing - oil ok etc. etc.

Bizzare (I would have thought if the motor only get's to 90 deg so would the engine bay, but I guess exhaust temp is higher and while engine is'nt running coolant is not circulating either so Engine bay temp can rise after driving?) I plan to fit hose's and temp gauge next week so should be able to keep tab's on coolant temp- would like to know what's going on other wise changing thing's adds more variables to the situation.

I dont think that I'm actually running it hot - except when the cab get's warm that seem's a little bit odd - not being very familliar with the bongo doesnt help.

[dandywarhol]

Allan doesn't like the idea of a switch, IF affects the ECU operation.

Nice to hear another authoritive voice on the subject..................

Karlos, the cab gets warm cos there's a feckin' great 2.5l turbo diesel lump sitting in it just don't put your chocolate eclairs in the cup holder bits for too long...........

[mikexgough]

I drove it for at least 1/2 to 1 hour to get engine warm with a few stop starts to see when or if the the fan would kick in (could not get it to kick in) when I gave up I pulled into petrol station to top up - fan not running - after fillling up putting the ignition on ,waiting for glow plug light to go out, the fan came on for about five sec'c then went off - so I'm guessing as the van stood the rising heat with no cooling air flow, raised the engine bay temp enough, after all the block is like an old cast radiator when stood still.

If I had fired it up quick, or drove the air flow/vacum probably would have stopped the fan coming in, It actually seems quite normal to me -

it's not running temp it seems to be the standing radiating heat. (strange how I left it ticking over prior to stopping at the petrol station after driving round and it didn't fire the fan up, and after leaving the petrol station when the fan had cut in, obviously driving cooled the motor a bit, but I could nt make the fan cut in again?)

The princable sound's right but none of you have expeirenced it, It obviouly involves driving till the engine is at max temp, parking up briefly not giving the engine time to cool then turning the ignition on "fan cuts in" seems very inconsistant though!

I might change the engine bay ambient switch,plug and a bit of the wire in the loom, the sender's plug wire's look as If they have got a bit hot at some point, but cannot be totally open circuit - seems a bit hit and miss , but it does seem to co inside with cab getting warm whilst driving. all though the coolant doesnt over heat in anyway, the temp seems to rise and drop, it will fall even after a long journey with steady driving, but some times the cab does seem to get warm?

Coolant not boiling or disappearing - oil ok etc. etc.

I dont think that I'm actually running it hot - except when the cab get's warm that seem's a little bit odd - not being very familliar with the bongo doesnt help.

Mine does the same, fan runs minimal amount sometimes in heavy traffic and summer heat but mostly via heatsoak after a short stop, never loses coolant or boils, uses oil over mileage(normal) and Temp gauge is (on a 10-2 clock dial) sits around 12:00 to a max of 1pm under load conditions, others here may say the same....or not...

[Doone]

Our fan's more or less the same. We have recently changed just about everything you can possibly change in the cooling system (full story on Allans website) and we know that everything is operating as it should. We have also fitted a different temperature gauge, so we know that the engine temperature is absolutely spot on.

[bigdaddycain]

If the fans don't operate when the plug is removed from the sensor, then in all likelihood you have an actual fan related problem. Try running 12 volts to them directly to test them.

I can test/operate my all my fans simultaneously by flicking a switch on my dash,the unpowered switch effectively "pulls the plug" hence fans operate! My ethos is preventative cooling, as opposed to cooling something that is already scorching hot.

[karlos]

Cheers, guy's I thought after testing it seemed kind of normal, just getting paranoid about overheating!

I agree with dandy a switch only opperation is a bit poo (if that was the senario)! may cause problems,

I might install a switch in one of the cables from the sensor in series so that the sensor works in switch one position, the switch with then act like unpluggin the sensor in the other position switching the fan on when desired, which will keep it running until the switch it off putting back on sensor so auto and manual effectively.

In manual it would be hard to ignore the fan so impossible to leave it on and would stop on ignition anyway.

I think for heavy traffic it might pay to have a manual over ride especailly if the calibration of the sensors is questionable. since the last post the fan has not cut in so all is well

thanks again every one - might even try to make it to a bongo bash some time to have a poke around a other peoples inovations.

"I do/did plan on fitting a deg c temp gauge this week for accurate data. does the existing temp gauge sender actually penatrate the water jacket on the cylinder head (i.e does water pee out when removed) or just pick up on radiation/inturnal surface temp. If it does not make contact with coolant I will be putting a tee in the coolant pipe!"

[bigdaddycain]

Hi Karlos, The fans on my bongo are operated via the ECU, however, i have fitted as a precaution a MANUAL override switch for the fans (including the scavenger fan). I feel that the ECU allows the engine to get a bit too hot before it kicks the fans in, the ECU cannot predict a long ascent, nor can it tell if a caravan is being towed, or if the vehicle is heavily loaded on undulating surfaces. I'll give you a quick scenario... Loaded with people on the climb out of Colwyn bay on the A5 holding my steady 65MPH as per, the mason alarm chirped around halfway up... ECU had not at this point engaged the fans, so i did. 2 seconds later, mason alarm shut up, temp gauge needle was holding steady at 12 o clock, (from the ammended mason alarm indicated 2 o clock). The switch is unpowered (it simply breaks the circuit) so can't affect the ECU in any way, it simply removes the plug to the temp sensor switch, effectively switching the fans on...No harm done.

[dandywarhol]

I've been stupid with this one - bigdaddy's post makes sense - I've been assuming all along people are feeding power into the the sensor circuit - breaking the circuit is a far better way of doing it.
Though, I have found that disconnecting the circuit doesn't always bring the fans on though, it's more of a flicker that triggers the ECU