Cold bottom hose... Help needed for a Bongo Newbie.

[Good Friday Girl]

Hello all.

I've had my Bongo around 3 weeks now, and love it. However, there's one issue I'm uncertain about. I bought it from Direct Campers who have been immensely helpful, and am hoping they'll be able to sort this out, but just thought I'd ask the oracles on here for any advice/ information you might be able to give me.

To start with, the temperature sensor rose gradually to the 11 o'clock position and stayed there. Then it started to 'flicker' occasionally, down to zero in a sudden movement and back up again. Gradually over the last couple of weeks that's got more regular, and on a long journey today it spent the last hour or so firmly stuck at zero.

I've done a bit of googling and looking around, and these are the symptoms I can come up with:

The bottom radiator hose was completely cold after a 4-hour journey, which I believe should not be the case.
The front heater works fine- it pumps out plenty of hot air on demand.
The coolant in the expansion rises slightly (about 2cm) after a long trip, but then drops back to normal again overnight. It hasn't lost any coolant at all while I've owned the vehicle.
The hoses are all in excellent condition.

So... I'm led to believe it might be one of two things: either an electrical fault with the sensor, or an airlock in the coolant system.

Any thoughts from the experts out there...?

I'll hopefully be taking it to Direct Campers on Wednesday so they can have a look at it.

[Northern Bongolow]

it is the wire to the sensor, just give it a wiggle. and stop reading those scary coolant threads
if its a diesel its under the drivers seat at the front of the cylinder head, single wire to it.

all the symptoms you list above are exactly right,they are normal.

[jaylee]

it is the wire to the sensor, just give it a wiggle. and stop reading those scary coolant threads
if its a diesel its under the drivers seat at the front of the cylinder head, single wire to it.

all the symptoms you list above are exactly right,they are normal.

Not disagreeing with Ady's initial post... (Happy new year mate!)

But, i would be careful & go easy of the "wiggle" or juggle!! Remove the connector & clean the contacts... Not to break the unit.!!

http://lushprojects.com/bongopartsmk2/c ... no=.html#5

Could be a bad earth where it's screwed in..?

[Diplomat]

Nobody's commented yet on why the bottom hose is cold.

Is the heater and good forward motion enough to cool the engine at this time of year?

I would have thought that a four hour journey would have damaged the engine without sufficient cooling!


Frank

[Northern Bongolow]

happy new year mate, and you make a good point . 18510 on your listed lushy diagram.(wish i could do puter magic).
hi frank, in my opinion the fact the heater/s are on removing heat from the system, and the forward motion combined with a healthy efficient system/rad/stat may mean that its working well within its controlling limits, in fact towards the lower end.
sounds like a good bongo to me

[francophile1947]

Nobody's commented yet on why the bottom hose is cold.

Is the heater and good forward motion enough to cool the engine at this time of year?

I would have thought that a four hour journey would have damaged the engine without sufficient cooling!


Frank

My bottom hose never got hot on a journey either, unless I got stuck in traffic or it was a boiling hot day. Never caused me any problems I still think the heater radiators do most of the cooling.

[jaylee]

I must admit to being puzzled that after the vehicle has stopped, (The only way you could check the pipes!?) why the bottom hose is cold..? Yep, the rubber parts of the system in my opinion are easier to touch than the metal bits.. But "cold"??

Should the temp not be similar'ish throughout the coolant system "to the touch" given that the water pump would have been pushing the coolant round idling at a slower pace with no airflow though the rad with forward motion before stopping when the ignition is off? Even if the fans were running... (Which the fans wouldn't be with the engine off if they had come on.)

[The Great Pretender]

My new year resolution is to not get involved in how the cooling system works again as I understand it fully..................NA........NA..........NA.........NA..............NAAAAAAAAAAA..................

[francophile1947]

I must admit to being puzzled that after the vehicle has stopped, (The only way you could check the pipes!?) why the bottom hose is cold..? Yep, the rubber parts of the system in my opinion are easier to touch than the metal bits.. But "cold"??

Should the temp not be similar'ish throughout the coolant system "to the touch" given that the water pump would have been pushing the coolant round idling at a slower pace with no airflow though the rad with forward motion before stopping when the ignition is off? Even if the fans were running... (Which the fans wouldn't be with the engine off if they had come on.)

The bottom hose is cold unless the thermostat is open - mine rarely was.

[widdowson2008]

I must admit to being puzzled that after the vehicle has stopped, (The only way you could check the pipes!?) why the bottom hose is cold..? Yep, the rubber parts of the system in my opinion are easier to touch than the metal bits.. But "cold"??

Should the temp not be similar'ish throughout the coolant system "to the touch" given that the water pump would have been pushing the coolant round idling at a slower pace with no airflow though the rad with forward motion before stopping when the ignition is off? Even if the fans were running... (Which the fans wouldn't be with the engine off if they had come on.)

The bottom hose is cold unless the thermostat is open - mine rarely was.

And even when the thermostat opens, the bottom hose can stay quite cool if the radiator is doing its job efficiently. Sounds to me like 'Good Friday Girls' system is in very good order.

[haydn callow]

Next time you go for a decent run..(about 30/60 mins) leave engine running and feel bottom hose...probably cool/cold....leave it running at 1500 reves for 10 mins then feel again....probably much hotter.(stat open)

[Good Friday Girl]

Thanks for all the tips people. I lifted the drivers seat this morning, and had a fiddle with the wire to the sensor. Unfortunately though the van's a full conversion, and it's quite difficult to keep the seat up while I poke around in there. On a quick drive that did seem to make a difference though- the needle still 'flickers' occasionally, but it definitely spends more time sitting at 11 o'clock. I'm taking it in to Direct Campers tomorrow so they can have a look at it while someone holds the seat up!! Hopefully it'll be as simple as a dodgy sensor or connection.

With regard to the bottom hose question- Haydn, can I do that test when the engine's cold? i.e. when I haven't been out for a drive beforehand? If so I could do that this afternoon.

[dunslair]

Hi GFG
Sounds like the problem is the elctrical connection to the sender. I am sure the supplier will be able to help you with a quick fix. Best of luck with this and let us know how you get on on Wed. hope to see you at a meet next year some time.

All the best

David.

[Good Friday Girl]

Thanks David- will do. They're going to check the electrics, but also check for an airlock just in case. The rest of the Bongo's in immaculate condition, so there's no reason to suspect that the cooling system would be any different.

[Good Friday Girl]

Well, I took my beloved Bongo to Direct Campers in Kilmarnock this morning, and they put in a new temperature sensor which has cured the problem. They also bled the system just in case, all for no charge. Sorted.

Haydn- I haven't tried what you suggested yet but will do next time I drive for a reasonable length of time, out of curiosity. I'll let you know how I get on when I do.

Thanks everyone for the suggestions & help.