Overheating? Shall I panic now?

[smac02]

Hope that some of you more experienced owners with water (if you know what I mean) problems can advise.

Have had my diesel Bongo for just two weeks. Have driven about 750 miles in it with no obvious problems, other than thinking the fans were coming in more than I would have thought for this time of year, but not running all the time.
The temp gauge has always sat solidly at 11 o'clock and no signs whatever of water loss from the header tank. But, after reading the horror stories I today fitted a Mason temp gauge device. The gauge then sat at 1 o'clock at tickover. As soon as I took the Bongo for a run the needle went quickly towards the Hot end of the gauge, like almost on the H. Still no signs of problems or water loss though. No bubbling of the header tank etc.

What do you reckon? The Mason device is giving a false reading? There is an air lock and the system requires bleeding? Head gasket failed? head cracked? Blocked radiator?

I did drain some of the water from the rad and it was filthy brown with the first cupful being like black sludge.

So, shall I start looking for a new head and a friendly mechanic? If so is there a good Bongo specialist in the Doncaster or Leeds area?

All advice welcome as I want to sort this potential problem and stop worrying that I've just bought a costly lemmon.

Steve Mc

[Peg leg Pete]

First thing, do not panic, I would change and bleed the coolant, Flush before filling with new coolant Rusty water needs to be removed, check all hoses, check thermostat, mason alarms are very sensitive so might need to be calibrated

[robdrinky]

initally dont panic,the mason alarm does make the temp gauge react more.
apart from what you have already done it sounds like a water change and flush is needed(with caution & read up on correct bleeding procedure).
then see how it reacts.
lots of info on this subject in other posts,have a good read.
best of luck

[mister munkey]

The Mason Alarm has bought issue this up before. Because it gives a more positive reading over a narrower temperature band, they sometimes need a little tweaking to suit each individual engine setup.

Most seem to end up setting theirs at 4.5.


Have a quick search, you'll find plenty on here.

[heatherpetch]

Hi there i am sure you will find it is simply the masons alarm that actually makes the needle move,after we fit ours the needle goes just below the h position,ours is set at a tad over 5 and for normal running it never alarms although if going up a steep inline it does alarm then stops,hope this helps can't comment on the sludge from the tank need someone more techie than me.I am sure that all tell you it's ok for the needle to move alot more than normal,don't be paranoid not all bongo's have problems we just hear about the ones that do

[smac02]

Feeling better already. Thanks for the speedy responses. I'm reasonably good with mechanics as I grew up helping my Dad who was an old fachioned mechanic and was in engineering for a few years before my present long term job. I'm even enjoying getting hands on with a vehcile again (up to a point). I've read all the posts and have a copy of the manual.
It's just that these pages are full of doom and gloom about the cooling system. It also seems that the cooling system is a little tempremental and has to be closley watched.

Can I assume from the replies then that with the temp alarm fitted it's not so unusual for the gauge to show in the high end for normal running? I understand that the device 'undamps' the gauge but was surpried that it swung so wildly!

Looks like my first job is to give the cooling system a good flush out and read up on the bleeding procedure.

Thanks again and anymore tips would be welcome.

Live in the Doncaster area by the way.

[Peg leg Pete]

flushing and bleeding most important, any questions ask away

[mister munkey]

Here's a liink to a previous.



http://www.igmaynard.co.uk/bongo/forum/ ... n&start=24

Halfway down page two is a piccie guide that explains how they work in laymans terms.

[mikeonb4c]

If you are concerned about a sludged up system and have a few spare £s in your pocket, maybe drain the system, flush it, then fit new thermostat and radiator. It soulnds as thought Bongo is coping OK at present, but I do wonder if that sludge may have clogged the radiator matrix and it may works wonders with a set of new clean tubes

[dandywarhol]

The Mason alarm does allow the gauge to rad accurately and 1 ocock is normal. Running to the "H" at this time of year is going to cause you problems sooner than later.

I think you've answered your own question smac - flush it out BUT reverse flush it from the bottom - that way any sludge can be forced OUT of the matrix rather than IN. Even better to remove the radiator to do it.

When you refill/bleed the system then feel as much as the matrix as you're able to and if there's any "cold" spots then change the radiator IMO

[coco bongo]

If you do take the rad out to flush it, maybe take it to a garage to be flow tested. My old one had loads of crap in it, which no amount of flushing out made any difference. It was also 33% inefficient.

So like mike says if youve got any spare cash get a new rad and thermostat.

Best of luck
Darren.

[smac02]

Thanks for all the advice one and all. Today I took out the rad and flushed it through. Lots of dark coloured water and some gunge came out and in all it took about 15 minutes to get clear water through. All in all though the flow rate was good. As fast as I pushed the water in through the garden hose it came out just as quickly with no backing up.
Also flushed through the engine hoses, block and expansion tank. Difficult to gate any rate of water through the engine block though because the thermostat would obviously be closed.

Put the rad back and tried to bleed the system following the manual to the letter. Took me ages and with no real success. All I got was a very hot engine, with gauge at the top end (Mason alarm installed) Tried several times but only succeded in having lots of hot water spluttering out of the bleed hose.

I let the engine cool, read more the posts on the forum and tried the 'see saw' method. Much more sucessful. I could control the flow of water and see the air coming through the system into my glass container. I don't think I did a 100% job though because I was single handed and feel that this is a method better employed with a helper.
In the end the top hose was hot but could be held without being burnt, the bottom hose was cold but I could feel slight warmth in the bottom of the rad.

The end result is a little mixed and still slightly confusing. I think. With my Mason alarm fitted the gauge operates around the 75% mark under light driving and moves over to about 85%+ when I push the engine revs.
I been able to set the alarm at 4.5 on the dial without is sounding.

However, even under light driving every time I've stopped the fans are running. Even with this evenings outside temperature at about 8C.

Tomorrow I shall have another go at bleeding the system with some revs on, again using the 'see saw' method.

If as the weather warms in the next minths ahead I get any signs of overheating I shall then begin by chnaging the rad and thermostat.
Fingers crossed.

Any further comments or advice is welcome. Thank goodness for this forum and the members club.

[richrich]

I today fitted a Mason temp gauge device. The gauge then sat at 1 o'clock at tickover. As soon as I took the Bongo for a run the needle went quickly towards the Hot end of the gauge, like almost on the H. Still no signs of problems or water loss though. No bubbling of the header tank etc.

What do you reckon? Steve Mc

Hi Steve

If it were me, I would remove the Mason alarm - honest

[coco bongo]

Let's hope you've got it knocked! best of luck.
By the way, do keep in mind the new rad and thermostat, sooner rather than too late.

I had to have a waterpump as well when mine went, the crap that was going through it was like pure concentrated evil!!. And it bent the fins over

[B*Witched Blingo]

I hope you get further tomorrow.... Good luck....Well done for trying so hard.