A question for Haydn regarding V6

[chakota]

Hi Hadyn,

Can you tell me if its worth purchasing one of your coolant alarms for my V6 as looking through other posts it seems the diesels seem to be the main sufferers of this overheating problems or am i wrong.

Many Thanks...............Harry

Ps. If i have to purchase one .... what is your recommendation

[haydn callow]

Carn't really answer that on the forum (it's the rules you know)......PM sent

[Northern Bongolow]

no but i can!!!.
get a low coolant alarm,at least.and maybe the gauge modification.that would be the minimum i would go for. i use the i-alert to.
there is also the mason alarm that is very good to.(made by another supplier).
for the modest investment i consider them good value against the price of repairing the head.

[apole]

Hi,

Would second that. I have a V6 and was on the fence for a while. The cooling system is very similar/the same as the diesel, with many shared parts and the same complicated runs of pipes.

In 4 years I had one total coolant loss whilst the car was standing, when one of the rear heater pipes gave up. Luckily that happened when the car wasn't in use and I spotted it.

The V6 would still get damaged if it was run on low or no coolant due to overheating, and it has 2 heads to be repaired and 24 valves so it could get costly.

I've had one for a while now and they are good, I had a weeping hose and the very slow drop in coolant level was picked up by the alarm.

Hope this helps.

Andy

[chakota]

Many Thanks Lads for your input , you have made my mind up and i shall go for one asap.

Cheers Guys .......... great forum with friendly people Harry

[Ron Miel]

Carn't really answer that on the forum (it's the rules you know)......PM sent

Pity if you can't at least give any comparative statistical info if you have it Haydn?

Even though, as Andy Pole says, the cooling system is similar, the rest of the V6 engine is definitely not - does the V6 cooling system normally run at the same temperature as the diesel; are the two V6 heads better at dissipating heat than the one in the diesel; what impact does the much higher diesel engine compression ratio have on rates of head failure following coolant loss; etc., etc.? Have any V6 heads been known to cook/crack following coolant loss in BF members' Bongos?

Like Andy, I've had two episodes of coolant loss in my V6:

The most recent one was an apparently cold weather induced rear heater matrix failure, which occurred while the motor was parked up for a long period, and was detected and repaired before next running the engine. Coolant anti-freeze strength was fine BTW - my guess is that the matrix simply gave way after repeated thermal shocks last February, repeatedly going from arctic temps overnight to engine temperatures when run the next day. However, if it had not been visually (pool of water) detected, our coolant alarm would of course have alerted me as soon as the ignition went on.

The second one, due to a nipped top hose when a garage re-fitted its jubilee clip at the engine end, following a cambelt change, is more directly relevant. The engine had slowly lost coolant in a very small leak (actually under the clip) I could not find, ever since we got the Bongo, then eventually suddenly completely gave way under pressure and at full operating temperature. Result - half an inch exposed hose split, tank half emptied, coolant alarm (fortunately fitted only the week before) went off, engine was stopped immediately. The coolant didn't disappear right out of the bottom of the expansion tank, and I was able to temporarily stop the leak by moving and tightening the jubilee clip until I got a replacement hose. The TM-1 temperature monitor, also just fitted, showed no appreciable temperaure gain, other than the the usual hot-spots-conduction rise after the engne was stopped - that has since largely ceased, after also installing Motormax coolant enhancer.

So, I can't tell you how comparatively fast V6's cook up, if coolant is lost and not detected, and it would still be useful if anybody has any information on that. However, I'm another one saved from having to find that out, by the coolant alarm - glad to see you're also going for it

[g8dhe]

There was the survey that Ian carried out here in the March Newsletter;
Also this from Ian;

In total, 1,288 people responded. When asked "Have you ever suffered from coolant loss or overheating problems?" 292 (or 22.7%) said yes. A lot higher than anticipated, certainly by me. But out of these, only 9 (or 0.7%) owned a petrol Bongo.

and of course plenty of discussion resulted here http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=38581

[Ron Miel]

There was the survey that Ian carried out here in the March Newsletter;
Also this from Ian;

In total, 1,288 people responded. When asked "Have you ever suffered from coolant loss or overheating problems?" 292 (or 22.7%) said yes. A lot higher than anticipated, certainly by me. But out of these, only 9 (or 0.7%) owned a petrol Bongo.

and of course plenty of discussion resulted here http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=38581

Thanks for the reminder Geoff. I've just re-read all 98 posts, and it wasn't until the final Page 7 that I found I had burbled on in that thread - to the tune of 5 posts in 1 hour 15 mins(!), and yet had since completely forgotten it. Mind you, I was just one day home from hospital and pretty high on Tramadol at the time, so perhaps I shouldn't be surprised - was actually barely out of theatre when the thread started Yes, lots of useful stuff there which, having since forgotten it, I had recently thought was not available.

Even so, perhaps the way I expressed my implied question this time ("So, I can't tell you how comparatively fast V6's cook up, if coolant is lost and not detected...) is still a bit interesting, if/when it can be answered. Doone's experience with heavyweight bubbling beneath her seat must have been very disconcerting indeed Would the two heads of a V6 spread the experience across to the driver's side too, or would its lower compression ratio produce a less explosive overheat outcome in the first place? I seem to remember that the main difference between that V6 in a Bongo, and it's earlier use in Mazda 929's was that the compression ratio was lower still in the Bongo, and its power output thus reduced.

Cheers

David

[apole]

Hi there,

I can't recall who it is on here, but there was someone a few months ago that had a V6 from hillside that overheated and had to have both heads on it replaced. From memory they did that under warranty but didn't address the root cause of the overheat and further problems occured.

I can't say if the V6 is less problematic if it overheats but I don't want to give it a go either to find out !!

Like David my coolant loss from after a cold spell in the rear matrix, and again the coolant wasn't old and up to strength with anti-freeze.

I would think if you lost coolant in a V6 then the heat build up would be on both sides of the engine, they are both burning fuel and creating heat after all.

A while back when my thermostat was being replaced (with the wrong one as wrong part supplied) the car would get hot very quickly. Luckily it was in the workshop at the time so overheat didn't occur, but I was there and it did get hot fast, plus it was only idling and not driving on the road so that would indicate if you were driving up a hill or at speed the overheat would occur faster. Also isn't the temp sender only able to work if immersed in coolant, if that were gone would the temp gauge alone work at all or in time?

What is the engine and head made from and am I right in thinking different metals suffer more than others?

Anyway, overall and in summary I think the coolant alarm is well worthwhile, I'm happy with mine.

[Ron Miel]

The TM-2's temp sensor/sender is a purely surface mount job Andy, so it keeps going fine - isn't that what you've also got?

[The Great Pretender]

I believe the stat on the V6 is on the inlet as on the diesel (the 2lt is on the outlet). Control of coolant temperature is more important as pressure in the head(s) is lower and therefore boils at a lower temperature.

[haydn callow]

The causes of coolant loss are much the same for any Bongo..Hoses/Rads/waterpumps etc....the effects of coolant loss and subsequent overheating are less well known where petrol Bongos are concerned.........there are at the moment far fewer Petrols on the road but this is changing as the supply of good Diesels is drying up.
Having said that I have heard of plenty of cases where a V6 has had a alarm fitted and it has "early" warned of Coolant loss....I have never heard of a 2lt having a problem but they do have a cooler running engine.

[casrockbongo]

Hi all
It was my Bongo from Hillside that overheated and yes cracked head (s). So it can happen . . and unfortunately was not under warranty, no overheating work is. I had an alarm fitted following my first coolant loss incident (burst pipe) and it has saved me from a second one, when my rear heater matrix went. So I would definitely recommend. I wish I had had one sooner - would have saved me a very expensive job.
H

[The Great Pretender]

The causes of coolant loss are much the same for any Bongo..Hoses/Rads/waterpumps etc....the effects of coolant loss and subsequent overheating are less well known where petrol Bongos are concerned.........there are at the moment far fewer Petrols on the road but this is changing as the supply of good Diesels is drying up.
Having said that I have heard of plenty of cases where a V6 has had a alarm fitted and it has "early" warned of Coolant loss....I have never heard of a 2lt having a problem but they do have a cooler running engine.

Yep a Bongo is a Bongo is a Bongo, loads of pipework and an engine in a suspect position when there is a leak, protection required. When it comes to the 2lt is this statement true or a myth? 'I have never heard of a 2lt having a problem but they do have a cooler running engine'. It has been around for a while but any engine in the Bongo has to use the same horse power to do the same work.

[mikexgough]

The Mazda FE engine and subsequent variants are really "Bullet proof" engines and have no major issues known....although like all engines will overheat if the 'stat plays up or cooling hoses fail, but in the main is very sound, however there is always the extra pipework to factor in with a Bongo.
The inline 4 has very few head and head gasket issues after overheats in "normal" Mazda cars, only in the Kia Sportage as Kia skimped on Head gaskets (in that fitment cylinder 4 was an issue on the gasket) so I would hazard a guess that they would be reasonably hardy if an overheat happened in a Bongo.....
For me usual coolant & hose checks apply and modifications to monitor are at owners personal choice and discretion