coolant hose

[cheffy34]

Think he's across waters till 15th

[missfixit70]

Bongo Bits then - or try your local mazda dealer for some boring rubber hoses

[cheffy34]

Personally i'd wait for some nice red ones they do reckon silicon ones are better, iv'e promised my beast of a v6er a full set apart from the odd one that don't match by the looks of it

[missfixit70]

I think he's only doing blue now, but he may have a few red ones left, don't think there'll be a full set as the 5 new ones were only done in blue.

[cheffy34]

Mmmmmmmmm well i'll have to compromise then cos i'm not havin rubber

[apssrf]

Hi, I have a coolant question and have decided to stick it on the end of this thread rather than start a new thread as I was thinking people might be getting fed up of coolant questions! We have had our Bongo for about six weeks now and it all seems hunky dory. It was a new import when we got it from a reputable garage. I have been getting a bit paranoid about the coolant/overheating etc after reading all the stuff on here. We have checked the coolant level and it is nearly up to full. We have taken out a small sample to see what it looks like and it is clear and a light blue colour with a chemical sort of smell so it def has some coolant in it though not sure if it is Japanese or British as the garage may or may not have changed it. Also not sure of the strength of the coolant.

I have also ordered one of those Haydn Coolant alarms as we do have experience of head gasket failure from another car we owned so I want to avoid that at all costs!!

My question is, do I need to do anything else at the moment? If not, what do I do if the coolant level goes down as I am a bit unclear what I need to top it up with (should I use Halfords Universal stuff in case it still has the Jap stuff in it?) Also, at some point I will need to get the garage to do a coolant change , should I just print off the relevant fact sheet and will that be all they need to know?

Thanks in advance for your help.

[missfixit70]

Check with the garage that the coolant has been flushed & changed, fit the coolant & IMO a Mason alarm too, covers just about all the bases then if anything does go wrong. inspect all your hoses whenever you lift the engine covers to check levels & if/when you can afford it, change them. coolant shouldn't need doing for 2 years, but the factsheet should give the garage enough info to bleed properly (if you don't do it yourself ) when it does need doing.

[flippa]

...Hi Guys im back from my travels 2 weeks in estonia , what a lovely country ,and what a great place to take the bongo ....thanks kirsty and cheffy for the heads up.....im back in business ...if you dont see what you need listed on e-bay just contact me i have a large stock of all the hoses.....except that elusive V6 one cheff

[mikeonb4c]

Welcome back flippa - any good pics of the trip? Sounds great and I'll tell you what mate, ya didn't miss any heatwaves here

It's been so wet, it wouldn't have mattered much if you did have a coolant leak as yer engine would have been submerged anyway

[Simon Jones]

I have also ordered one of those Haydn Coolant alarms as we do have experience of head gasket failure from another car we owned so I want to avoid that at all costs!!

I've got a Haydn alarm, Mason alarm & TM2 Engine Watchdog, in addition, I've had a head gasket failure, so I feel I can comment from personal experience.

The Haydn alarm does exactly what it claims to do: it will detect a loss or drop in the level of coolant in the expansion tank. Typically, this would be relevant if you have a split or leak in a hose, or a hole in the radiator matrix. If a hose burst whilst driving, the pressure in the system would soon cause the coolant level to drop & trigger the alarm.

A head gasket failure whilst the engine is running will force exhaust gas into the cooling system at great pressure. The weakest point in the system is the cap on the expansion tank which will lift at 1.1 Bar to allow the water / gas to escape via an overflow pipe. In this instance the level of water in the tank will be rising not falling & in theory will continue to rise until all the coolant has been forced out the system.

When my head gasket failed, I was lucky in that I noticed the water was coming out the overflow, but if I'd been be driving on the motorway this would have gone undetected until the damage was done. As a result, I have built my own sensor & 'excess pressure' alarm which saved the day in Poland when I had an air-lock in the system due to a small cut in the bleed pipe. Air had been sucked into the bleed pipe when the van was stopped & then it has expanded causing the water level to rise until it was forced out the over-flow pipe. The solution was to cut out the damaged section of pipe & then bleed the system thoroughly.

The majority of the problems with the cooling system can be prevented or at least minimised by regular checking & replacing the coolant, changing the thermostat, back-flushing the radiator, bleeding correctly and checking the hoses for signs of damage or cracking. The alarms currently available will only help detect a problem whilst they are occuring, which hopefully should allow you to react accordingly before serious damage occurs. The old adage: prevention is better than cure, is especially true in this case. You could go the extent of replacing the radiator & all the hoses, which would still be a fraction of the cost of a replacement engine. Should you go to that extent? Personally, I replaced the parts which were showing their age & make sure I check everything regularly. Don't forget - new items are just as prone to failure in their first few hours of use. I'm sure we've a fitted a brand new light bulb at some point, only for it to blow as soon as it's switched on.

A head gasket failure is unfortunately one of those things which there is nothing that can realistically be done to stop it happening. A Mason alarm or TM2 would indicate that the engine temperature was rising as a result of the reduced cooling effect caused by the escape of water. I fear that by the time all the water has been pumped out of the system, the engine temperature would already have risen to the point where cracking of the head would become likely.

There are many scare stories about coolant problems, but put in context of the thousands of Bongos running around the UK, I beleive it is just a small minority of us who have problems, & that tends to be the ones you hear about. In another thread in the last few days, Keefysher mentioned a friend who had head gasket failure on a car with just 15 miles on the clock, but you don't ever hear about the other cars that go on to run for one or two hundred thousand miles without significant problems.

[mikeonb4c]

The old adage: prevention is better than cure, is especially true in this case. You could go the extent of replacing the radiator & all the hoses, which would still be a fraction of the cost of a replacement engine. Should you go to that extent? Personally, I replaced the parts which were showing their age & make sure I check everything regularly. Don't forget - new items are just as prone to failure in their first few hours of use. I'm sure we've a fitted a brand new light bulb at some point, only for it to blow as soon as it's switched on.

I cannot overstress how much I agree with this. After all, you insure your car whether it is new or second hand and the insurance is a fraction of the cost of replacement should the worse happen (with the coolant alarm it's a one-of payment too!). Simon's view is well worth listening too, as he has had a head problem and not panicked and sold the Bongo, and is now reaping the reward. Fitting a load of new hoses, water pump, radiator (how far do you go?) will lessen the chances of a leak, but at a cost. If that cost is too much, then fit the low coolant alarm as a minimum. If in any doubt about the cooling system being a bit clogged, fit the engine block alarm (or Mason alarm) too.

I did the same as Simon. I fitted a coolant alarm and assessed the hoses (as being fine). But anything could go anytime, and I know that and have 'insurance'. One year after fitting and - touch wood - no leak as yet (though I have my beady eye on one hose which is looking slightly iffy.

[Grahame at work]

Hi Simon - I've gone back to this thread to ask this as it's more Techie than the recent Chat thread.

Would you tell me what type of sensor you have used?

I have been thinking about this since I heard about your experiance on the way back from Poland.
I assume it's one of
direct pressure sensor (could be costly)
movement detector on the stat (DIY mod to the stat so relaibility considerations)
flow sensor in the outlet (may be unrelaible)
fluid sensor in the outlet (may need more complex circuits)

I'm not wanting to pinch you design but to see if you have gone through the same thought as I am now.
I wish I had talked to you while we were in Poland - didn't seem to get much time for that

Regards Grahame

[Simon Jones]

Grahame - I'll drop you a pm.

[dandywarhol]

A head gasket failure is unfortunately one of those things which there is nothing that can realistically be done to stop it happening. A Mason alarm or TM2 would indicate that the engine temperature was rising as a result of the reduced cooling effect caused by the escape of water. I fear that by the time all the water has been pumped out of the system, the engine temperature would already have risen to the point where cracking of the head would become likely.

Simon, I believe the Mason alarm would warn of impending doom long before the head/gasket gets damaged - AS LONG AS IT'S SET CORRECTLY.
On a long autobahn gradient in 30 odd degree heat my alarm "chirped" - I had set it to sound just above the temperature the fans come in. I stopped at the next service station (which happened to be at the top of the climb) to check things out and nothing was amiss - it was just getting hotter than usual with the a/c on, heavy load etc. I then set the alarm up 0.5 to position 4.5. It was also hot enough for the scavenger fan to cut in through heat soak in the engine bay and to have the lower radiator hose to be hot.

[Simon Jones]

I guess it depends on what the cause of the failure is. If the failure is due to the engine getting too hot & the head warping, then Mason Alarm could be beneficial. I don't know what the cause of my failure was, but the trip it gave out on was a 5 mile journey across town. If I had continued to drive with the excess pressure in the system, all of the coolant would have escaped and then it would have over-heated.

I have just put it down to the effects of expansion & contraction over the past 9 years of use.

The location of the temp sensor is on the top of the head which is the highest part of the system in the engine. This is also the place where an air pocket is most likely to form. If there is no coolant in contact with the sensor, then it will probably produce a lower reading. The TM2 alarm would then be in a better position to monitor the increasing in temperature of the head.

That's why for my peace of mind, I've got several alarms that each monitor different factors, any of which could result in a breakdown, or engine damage.