Bongo Fury

I've only just joined and you must think I'm a right moaner... Long story but here we go...

Previous owner replaced full head, cam belt, pulley, water pump etc as he had major overheat. He's not really used it since then as it took him 9 months to sort it and he bought a new car so bongo was surplus to requirements. (Sounding good so far?)

Basically I have no idea of the history of the vehicle other than lots of major DIY work following a disaster. He seems to have done a good job on those bits and other service items such as filters, brakes, ATF etc were all done quite recently and new rad couple of years ago so not knocking him but I don't know what caused the meltdown and neither does he for sure.

We've done 700-800 miles(ish) since buying it with no heat issues. (did have glow plug drama but that's on another post)

We had a close shave overheat a couple of weeks ago where I'd opened the expansion cap while still a bit hot and blew a bit of coolant out. The van had been arse-up on big ramps overnight when doing exhuast (it's a fixer-upper) so maybe this caused the water blow-out situation. Couldn't top-up as it was up to the top of the tank. Van was off the ramps before removing cap and had been idling on drive for 10 mins. (I didn't know my wife had left it idling this long otherwise I'd have left it alone)

To try and settle it down, we went for a gentle drive keeping an eye on guage and it did go past "normal" to about 1oclock. The heaters belted out HOT air when I put them on. Was about 15mins driving and just doing steep long hill when it started overheating.

We left it to cool for 5 mins and when starting engine again the LCA went off. Probably the water which was previously stuck in the tank had gone back where it should be and sounded the alarm. On the plus side the temp guage was back to normal and stayed normal until we got home. It's been off the road since.

I've now bled the system both cold and then engine running and got out a fair bit of air.

I had it running at 3000 rpm for 20 mins and rad feels hot but the bottom pipe is a bit warm but not really hot. Temp guage still ok and no bubbles or steam from anywhere. I can just about touch pipe on top of rocker cover for a couple of seconds so not rediculusly hot but pretty hot.

Can anyone advise how long it takes for bottom pipe to get hot? Blowers front and back blowing warm but not really hot like when it previously overheated. (I've not got the blowers on all the time. Just to see if they are hot)

Rad fans have come on and off a couple of times during this time. Shouldn't the bottom hose be hot before the fans kick in?

I've borrowed a Testo 830-T1 Infrared Thermometer from work and plan to point it at the stat housing when I get home to see if the stat should be open or not. (I plan to get a TM2 in the not-so-distant future)

Any advice on this would be greatly appreciated as I really don't want another cylinder head meltdown and want to use the van tomorrow.

Thanks,
Alan

Hi

Lots of Bongo experts are away at Stourport just now, so hopefuĺly some advice soon.

Thanks Bob.

I'm kind of resigned to the fact it'll be off the road until I can get a specialist to look at it.

I don't mind fixing things myself, such as wiring, plugs, exhaust, new wings, respray etc as I'm quite handy but it's the risk of misdiagnosis I fear as I don't have the knowledge or kit required for these unique beasts and the cooling is so important.

I might just try a new stat as the cost is quite low but failing that I'm stuffed.

Well. I'm chuffed as hell to say that I've sorted the overheating issue.

My wife told me that it must have been my fault in the first place for leaving the back end so high overnight when changing exhaust and why don't I reverse the process and put the front on ramps overnight with a full expansion tank.

Reluctantly accepted this may be the cause and solution so tried it last night.

Just bled it with front end up on 40cm ramps and got loads of bubbles out into tank and a few from bleed hose.

Been for big test drive and fans only came on once when parked up after ragging it up a hill. They went off quickly after and pipe on bottom of rad is now hot as it should be so water now flowing again.

Maybe this could be a new and improved bleeding method?

Off to London from Bristol shortly but will be watching guage like a hawk.

Fingers crossed!

The bongo temperature gauge is not known for moving from the 11 'O' clock position until it's too late. If it was at the 1 'o' clock position that would cause me concern. When I bled my previous bongo it took about 45 mins before the bottom hose started to warm up. Then you get a release of more air that bubbles up from the bleed hose and into the funnel that you hold and move up and down during the bleed process. It was tempting to give up after half an hour but I followed the youtube video on bleeding the bongo to the letter. It's very important you stay the course and get every last drop of air out of the system, then you should be ok. I took the bongo on several european trips after this, at high altitude never had a overheating issue and the coolant level never moved. The fans do kick in at a set temperature, which I can't remember right now, but the info is out there and has been discussed on the forum.

Luckily we stopped as soon as it moved up and can't see any sign of damage.

Drove 140 miles bristol to London and around London so far since bleed and it's all good.

Thanks for everyone's input. This bongo community is great.

Aaarrrgggg.

Got half way back from London today and decided to get coffee from services. Once the engine was turned of for a mint it bubbles up and spits out about a pint of coolant from overflow pipe.

Why only after the engine was switched off? It was fine on motorway. Was it because the engine was really hot and had no water flow? Should it be kept ticking over for a minute before killing the engine?

I noticed the scavenger fan was not going but when I popped the passenger chair and checked temps with laser thermometer the head was 110 at hottest point.

Surely scavenger fan should be going if the engine is that hot?

Could this be why it overheated once I stopped?

Please help as I'm losing the plot. I'm shortly going to take a sledge hammer and grinder to it just for revenge.

When you stop and switch off after a long run the engine block will soak up extra heat and a extra 10degrees C is not unusual,
This can trip the coolant into BOIL with the results you experienced. Some folks on here wire the scavenger so they can switch it on manually.....
Suggest you re bleed the system ( about 40 mns for bottom hose to go hot) then next time you stop after a good run let the engine tick over for a couple of mins before switching off....this keeps the coolant circulating.

I would be more inclined to concentrate on the " Radiator Cooling Fans" rather than a scavenger fan. If this vehicle has been idle for a Long time You also need to have the cooling system checked for obstructions including thermostat. If that doesn't cure the fault I would recommend a Sniffer test.


Take care.

Thanks for the reply.

Rad is 2 years old according to prev owner. Rad fans work a treat as had them come on during my London saga yesterday and they really shift some air. Done combustion gas bubble test and nothing suspect although I'm planning on doing a couple more just in case.

It was off the road for 9 months while prev owner replace the head, pump, cam belt etc after meltdown. Something is obviously still amiss as the cause of that meltdown seems to be persisting. Luckily, being aware of the meltdown, I'm carefully watching for overheats.

Having just read the 40-odd pages of the cooling post (amazing diagrams and cross sections of head etc. Kudos to all involved) I'm going to change the stat as prev owner failed to do this when he filled the system after fitting head. He also failed to do 50/50 mix as he "didn't have enough in the garage at the time". Apparently a fully working stat and correct coolant ratio didn't seem too important to him after a meltdown (for f***s sake ???)

I'll report back in a couple of days when I've checked/replaced scav fan sensor, replaced stat, refilled coolant, bled system (YET AGAIN) etc etc.

PS. Has anyone ever used a hosepipe attached to the top of the system to blow out any crud from the bottom? Is there any risk of cocking anything up/breaking anything?

Thanks again for everyone's input. It's much appreciated.

Sorry... One more thing I was thinking might be a culprit with overheating...

I know it was "the thing", a few years ago, to blank off the EGR to gain extra MPG and mine seems to have been done at some point. (Quite a long time ago judging my the discolouration of the edge of the plate).

I know this can increase running temps. Would you think, seeing as MOT demands it now anyway, that removing blank (and cleaning manifold) would help overheating in, now very old, bongos that struggle with heat?

It may have been a good idea when they were only 10 years old but, now 20+, is it still such a good idea?

I very much doubt the egr would be a factor.

OK. Just trying to think of everything possible to lower temps.

Also, Has anyone MOTd their bongo with blanked EGR yet? Did it pass/fail? Did they even notice?

New mot rules just introduced, emissions are strict.

Older diesels made before particulate filters were built-in will not face the new emissions test so the mad panic to get rid of old campers before their MOT was a bit silly but tampering with any emission reducing system can result in, not only a fail, but £1000 fine.