Heater not great, radiator maybe?

[lucklesspedestrian]

Hi

I warned you that I'd be asking a few questions having just bought a Bongo for my daughter so here's number 2!

The van's actually pretty decent all round but one issue we noticed on the 500 mile journey from Devon where we bought it, back up to Scotland (a good test for any vehicle!) was that the heater does not get fully warm. It's the 2.5V6 new shape with digital climate control. If you set the temp to max i.e. 32, it does blow warmish eventually but it's clearly not working properly (the fan's fine) The coolant level is fine (made sure of that before we set off!) Engine temp is fine also. Do you reckon it might just need the coolant system/radiator flushing out again or is there any other possible cause anyone can think off?

ta

Steve

[ade33]

On the dash there is a cabin tempereature sensor - it looks like a bunch of little slots about an inch long. I've no direct experiance of the fault, but apparently the sensor can get bunged up with dust and debris and this may affect the operation of the heating.

Or blocked heater matrix perhaps? When you put the fan on high is the airflow out of the vents good?

[teenmal]

The first thing I would check with a new purchase is the running coolant temperature ( Nae hot water Nae hot air).

[lucklesspedestrian]

The first thing I would check with a new purchase is the running coolant temperature ( Nae hot water Nae hot air).

Makes sense, Is there a way of checking this other than looking at the temp gauge which sits steadily at just below half way?

Also, am I right in thinking that there are in fact 2 heater matrixs on the Bongo (front and rear) which might need flushed?

[Roy748]

Hi.
I had the same problem in my 2001 2.0l areo city runner bongo. Heat at 32 degrees but nothing much below. I researched and found what ade33 mentioned. Beside the glove box is the cabin heat sensor (3 cut out slats) clean this by removing the glove box and gaining access to it, removing the electrical wire is a little fiddly but possible. Mine was full of dust etc, I actually thought it had a sponge like cover over it, but no it was just years of dust etc. Once cleaned I had heat at all settings. Note at around 26 degrees most heat comes from the blower located in the foot wells and cooler air is blown from the dash vents, this was actually normal according to the owners manual for my model.

[g8dhe]

See here https://www.igmaynard.co.uk/bongo/forum ... 23#p530723

[lucklesspedestrian]

Brilliant, the cabin heat sensor will be my first port of call. Looks like something I can easily do myself. If that doesn't work then we'll go for the heater matrix flush. There's an outfit in Grangemouth not too far from my daughter in Edinburgh called Campers Scotland that advertise as being Bongo specialists so we'll get it in there if cleaning the sensor doesn't work.

Thanks again.

[Mark Wilson]

Bit of a coincidence, I've come on here with exactly the same query, and found what seems to be the answer. I hadn't tried it before, but turning up to 32 degrees demonstrates that the heater can throw out plenty of heat if it wants, so the matrix seems to be ok. I've taken out and cleaned the sensor as suggested, so should find out tomorrow if that has done the trick.

This is my first post, so can I say hi and introduce myself. We bought our 1999 2.5 Tdi at the end of July, it runs well but is in need of a bit of tlc. So far I've welded in a new front crossmember and fitted a low cooolant alarm, expect to be replacing all hoses and tackling the usual sills, rear arches and rear crossmember area next spring. Probably a mixture of DIY and one of the northern specialists.

Feels like I've hit lucky with this forum. I'm more often on the Morris Minor Owners Club site, which has been incredibly helpful during my restoration of a Morris Traveller, but you guys seem to be from the same mould, friendly and knowledgable. Thanks for the valuable knowledge I've picked up from you already!

Mark

[lucklesspedestrian]

Well, I cleaned the cabin temp sensor today, really easy job thanks to the helpful links on here. It was dusty so cleaned it and put it back. Unfortunately it didn't solve the problem. My heater also only generates heat at 32c but the problem is that it's not terribly hot. From reading previous posts on here It seems like the heater only being hot on 32 is actually normal for manual operation but auto allows for different degrees of heat (might be the other way about..... it's late and I'm 'tired'!)
My problem is that 32 is not terribly hot.

My daughter had an incredibly helpful phone convesation with a chap from campers scotland who really seem to know their stuff but unfortunately are not accepting bongos for repair other than their own. She's written down some suggestions which I'll have a look at in a few days time. Looks like the thermostat might be the issue (stuck open or closed) and also the obvious heater matrix needing flushed/bled. There's enough heat though to be getting on with. I'll post back when we get it sorted.

[mikeonb4c]

Welcome Mark and yes this is a great community and makes Bongo ownership much more practical.

Luckless- i think that these old systems merit a proper service anyway, so doing the sensor was a *good thing*. As suggested, i think taking off the inlet cowls and inspecting and cleaning the front of the heater matrix would at least eliminate it from enquiries (from memory, note how the recirculation flap spring is fitted before dismantling to avoid head scratching on reassambly). I recall the matrix has very delicate aluminium finning so crud (and decayed remains of what looked like it was once a filter mesh - the fastidious might want to replace that with something though i never did) has to be carefully and gently teased/plucked out. Seem to recall using a needle end bradawl for that. Once done, my mildewy musty smell vanished and air roared through. You might also be able to drive it with the cowl off so you can feel directly how hot the matrix is getting (maybe drive before dismantle so the test drive/engine run after can be shorter). Of the matrix isn't heating properly then this cleaning isnt going to help restore cabin heat.

The fact that your temp gauge is rock steady (and assuming it reaches that position after 5 mins from cold) makes me think your thermostat may well be ok. Another clue if it's faulty might be if you get much better cab heat when stuck in traffic (esp in hot weather) as opposed to on the open road, when the main radiator has better airflow through it so engine runs cooler.

Heater matrices have been known to crud up in poorly maintained systems. One test you could try is (when engine cold) squeezing the top hose to see if it is rigid or feels crunchy. If so it suggests deposit build up in the system, which will clog matrices (including main radiator). Another clue to history might be evidence of (rust) staining in the header tank. With either of these symptoms, and as a last resort, i'd consider replacing both main and heater rads. Main radiators on Bongos often develop a leak between plastic top to metal matrix join anyway as they get old and replacement is not too costly.

Hope this helps - just my personal thoughts and i'm not the last word on Bongo mechanicals!

[lucklesspedestrian]

Thats really helpful, thanks so much Mike.

[wonkanoby]

the cabin heater should get hot all the time,the flaps descide if hot air comes in or not

its feed by 2 hoses on bulkhead,they both should be very hot once warmed up

one being cold indicates the core is bunged up

[Mark Wilson]

Been out for a run, the sensor cleaning appears to have worked. Thanks all

[mikeonb4c]

the cabin heater should get hot all the time,the flaps descide if hot air comes in or not

its feed by 2 hoses on bulkhead,they both should be very hot once warmed up

one being cold indicates the core is bunged up

Great advice. Wanted to be able to suggest something like that but wasn't sure where those hoses could be easily accessed from (aged body - don't go into nooks and crannies much ha ha).

And of course, both hoses not being very hot after a drive might point at thermostat stuck open?

[Stevievee]

Cabin temperature sensor, had the glovebox out, but can't see it? What's it look like and where should I be looking?? Thanks