bleeding probs please advise

[falcoron]

Well i just fitted a mason alarm and went for a spin to set it. Was well aware that the reading wouls be higher than the standard temp at about 1 o'clock. was not ready for the temp rising to just under the max mark and the alarn going off. Panic! took her home driving perfect and heaters all working warm as toast got home in 10 mins and let her cool. decided to replace the coolant and give the system a good clean out so did this and to be honest some rusty coloured water but no crud that i could see and back flushed everything til clean water run out eveywhere, did the funnel thing with new antifreeze and let her run for abot 40 mins, got all hoses hot and heaters working. Replaced bung and took for a short run. Only got a couple of miles and the temp went right up to max and alarm going again, took her home put bleed pipe in funnel again with some coolant and opened the bleed bung, loads of bubbles came out so let her bleed again and got hoses hot again and heaters working took for a short spin and same again. alarm and hi temp on gauge. Felt bottom hose and this was now cold. Have turned her off as im loosing light. I'll let her sit all night and take another look.
All help greatefully taken. What am i doing wrong?
Thanks
Ron

[missfixit70]

What have you got the mason alarm set on to start with? You didn't seem to have a problem before, but panicked when the gauge reading was high.
I take it you were getting the bottom hose from the rad hot when bleeding? you weren't allowing any air back in to the system, ie you were keeping a level in the funnel & header tank?
Check you haven't got any tiny leaks, this will make it virtually impossible to bleed. Have you been having to top it up at all over the last few months?
After a drive the bottom hose will be cold as the rad will have been cooling - doing it's job. If you leave the engine running for 5 minutes or so after a run, the rad will warm up as there's no airflow & the bottom hose should get hot ( I got mine to measure @80 degrees) within 10 minutes of ticking over while stationary. If it doesn't get hot either rad is blocked up or the stat isn't opening up properly & shutting off the engine recirc/bypass.
Are you following one of the bleeding procedures properly or "winging" it?

[mikeonb4c]

Is it possible your Bongo is running hot (and you've just been made aware of it now your gauge is undamped). You might have a partially blocked radiator, or a gunged up thermostat, or even a compromised water pump. Rust in the coolant suggests the system is not clean as a whistle.

Waddya think Kirsty?

[falcoron]

Not winging it kirsty, you are right didnt have an issue with no mason alarm but the alarm wont make the guage go high will it?
No topping up either over last few months, all well really. havent set the alarm as i just went for a run to set it. It came at 4 on the dial so left it there. Its alarming just before the H mark, but its nearly at the H when it goes off. Before never got over the 11 oclock position. When i go for a run after bleeding all the heaters are warm, the rear ones are very warm and the front one is not as hot but nice and warm. Really confused why all of a sudden the hi temp is showing. Would the non mason gauge just sit there without going up even if potentually overhaeting?
Should i bump the coolant into a clean receptical and start again? Im using haydns system off the fact sheet and thought all was ok.
Checked for leaks also and cant find any.

[falcoron]

Is it possible your Bongo is running hot (and you've just been made aware of it now your gauge is undamped). You might have a partially blocked radiator, or a gunged up thermostat, or even a compromised water pump. Rust in the coolant suggests the system is not clean as a whistle.

Waddya think Kirsty?

The system was dirty and that is why i was going to clean it anyway. I flushed with a system flush and ran for the recommended 15 mins then dumped and back flushed rad and bottom pipe, the water was very clean before i renewed the coolant and bleed up.

[missfixit70]

As with anyone, I'd recommend a proper chemical flush(which you've done) & new thermostat - preferably a mazda original if you can get hold of one, drop the coolant at several points ie both the rear heater hoses, rad drain as well as bottom hose, & the lowest point on the rad inlet hose, there is a nipple on the metal pipe, but like to get in everywhere with a hose & flush through through everywhere I can, repeatedly. Check all the hose joints, hoses & metal pipes for leaks, as well as the water pump for any signs of leakage.
Rusty water not a good sign, could be coolant concentration was too low/old, meaning the anti corrosive properties wearing off, or it could be incompatible coolants have been mixed creating acidic mix & sludging.
As regards the Mason - that's why you've fitted it to tell you what's going on, as the original is so damped down, by the time the undamped one starts moving you could well have a big issue going on. Some peoples do run higher, but a few have changed stats etc & got it to run lower. Is yours going over the white mark at the end of the scale? Set your Mason alarm a bit higher, maybe 4.5?
Have you checked to see whether your rad fans come on? (disconnect the sensor above the hose above the starter going to the heaters on drivers side of the engine towards the rear, with the engine runnig the rad fan/s should come on, or they should be on if the a/c is on )?
Are you keeping the heaters on while bleeding? Or just checking then turning them off? If they're left on, it'll slow the bleeding procedure down & may mean you're not getting fully up to temp? Is bottom hose getting hot when bleeding?

[missfixit70]

It could be something as simple as the temp sender (above the top hose outlet on drivers side of the engine) not working properly, or needs cleaning up, giving a very slightly different reading? The temp gauge is not an accurate calibrated gauge.
Also you say you ran the chemical flush for 15 minutes, did you bleed it through, ie get the bottom hose hot? if not then it will not have really done it's job as it won't have got around the system properly, especially the rad. I did mine with the stat out (left the runbber seal in)

[falcoron]

Not sure if the system got hot enough when the flusher was in to be honest Kirsty as it states to run for 15 mins then bump and flush.
I checked her just now and all levels looked good no loss at all. started her and went for a 10 mile run, got to temp pretty quickly sitting at 1 oclock. Would never have shown before with a ten mile run. and the heaters would take a long time to heat up.
Heaters getting warm alot faster than before flush,rear again a lot warmer than front. temp gauge kept climbing right to white line and alarm came on. Noticed the front heater now a lot cooler than befoer but rear still blowing hot. parked her up for the night.

Would it be wise to start again and see what happens this time.
Thanks

[falcoron]

I got a new stat from a local outlet but its not original mazda its blue point, should i fit this tomorrow?
How do i change the themostat couldnt find it today though i wasent really looking for it.

[missfixit70]

Regarding the stat - here's a thread on how to - http://www.igmaynard.co.uk/bongo/forum/ ... thermostat
This shows the location 15-171 - http://www.lushprojects.com/bongopartsm ... mgno=.html
The fact that you're saying the front heater isn't getting as hot as the rear, or as hot as it used to concerns me a bit. People have had issues with the front heater matrix becoming blocked, which has made it just about impossible to bleed as well.

[falcoron]

went out bright and early this morning ( sun shine but cold) looked at level in expansion tank ( checked last night before 10 mile run and level spot on) the level was down a little about a centimeter below the full line, i take it the air may have come out by itself and this was the difference? Anyway topped up started her and gave her another 10 mile run the heaters came on warm very quickly
( would have taken the full ten miles to show only a slight warmth before)
about 3 miles in i had warm air from front and rear heaters. the temp steadily rose to just below the white line at the high mark the alarm chirpped in but this time the temp never went into the high as it did last night. the guage then came down a bit to about the 1.30 - 2 o'clock position ( either the fan came on or its just settled?)
All heaters now nice and warm, alarm off, steady gauge reading although higher than 1 0'clock. I really hope this is ok now as she is driving superbly.
I will leave the stat for now as its working fine. I will take her out this afternoon when she is completly cold and see if she does the same ( fingers crossed) the water is nice and clean too so i can assume the flush has done its job. Checked for leaks and non present. All the hoses seem nice and flexible not hard and crusty all the spring clips on the hoses are tight and corrosion free.
What a stressful day! though the engine was a gonner when i saw the temp rising so fast. Hope its sorted now.
Any comments welcome.
Thanks everyone especially Kirsty, god you must never have to buy a drink at the get togethers, i owe you a barrel full so far!!

[mikeonb4c]

Great news - Kirsty to the rescue as ever

[falcoron]

i will be checking levels for a few days to come, will it be normal if i have to top up a little after a refill and bleed procedure like this?

[scanner]

but the alarm wont make the guage go high will it?
....... Before never got over the 11 oclock position.

The alarm won't make the "gauge go high" BUT it will ALLOW the gauge to go high.

As standard the gauge is very heavily electrically damped so it sticks around the 11 o'clock point supposedly so as not to scare drivers by fluctuating up and down too much, it only goes higher than 11 o'clock under severe overheating and by then it's often too late.

This makes it practically useless as owners then believe it and end up having problems. The Mason alarm modifies the damping to give a more linear movement and thus a more accurate reading.

All you are seeing now is what Mazda were hiding from you with the standard gauge.

[missfixit70]

i will be checking levels for a few days to come, will it be normal if i have to top up a little after a refill and bleed procedure like this?

Sounds a bit more positive. About a 1cm overnight drop seems to be about normal, keep a good eye on your gauge & levels, have you got a low coolant alarm?
I'm suspicious of your stat & your rad from the behaviour you describe, personally I'd take out the stat & test it in a pan of water against the new one, I reckon it's been sticking & is possibly not doing its job properly. If it doesn't open up fully when it's supposed to, it won't force all the coolant through the rad (if it's not sludged up anyway) & then even if the fans are called on come on, it won't be cooling enough of the coolant to bring the temp down & it will be in danger of overheating. It seems silly to me to have a new stat & not fit it.
If the temp does start rising beyond what you're comfortable watching, stick both heaters on full heat & full blast to pull it down.
Some bedtime reading on the coolant system - http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=35902 &
http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=36433