help!!!! coolant rises then gets too hot?? water pump??

[chipvan]

hi guys,been having a spot of bother...

after changing a hose and fully bled the system using seesaw method with coolant on the max level in tank,the coolant rises to the top,

its fine when super cold and doing small trips.

the engine didnt over heat at any stage got to 100 0c max,i have a tam2 haydon led display high AND low coolant alarm.with probe bolted to the rear of block


no white in engine oil,starts fine
could this be the water pump,or thermostat??

not loosing any coolant over night..


Thanks guys just dont know what route to go down next

[wonkanoby]

is the stat opening

is bottom hose to rad hot

[progroup]

Do you remember the colour of the coolant upon changing the hose? Did it look merky, rusty?
What vehicle year, model, engine is this?
can you share any history like has the rad ever been serviced, or a stat changed out?

[Northern Bongolow]

sounds like it may not have been bled correctly mate.
watch the vids again, now you have some experience of doing it, the vids will make more sense.
pay special attention to the bottom hose getting hot, by hot i mean you cannot hold the bottom hose for more than 10 secs. were the heaters blowing hot, and did you feel the inlet outlet pipes to them both to make sure.

to be honest it sounds like you have got to the stage that garages who dont know bongo's get to, so do not drive it until you get to the bottom of the problem.
check that the expansion tank cap is holding pressure CAREFULLY, if its not, this would allow the coolant level to rise. or there is an airlock that is getting really hot, and its about to overheat and dump the coolant.

[321Away]

Agree with Ady, you havent completed the bleeding process, you've done 95% but you havent got the stat to open, seen this a few times. Do you have hot air coming from the heater? from a complete drain and refill the heaters usually come warm as the stat begins to open.

Julian

[chipvan]

Thanks guys,!!!!

Ive been trying to do it on my own by reving the engine with a stick ! so best get a helper,thought i did ok ish...

right

water clean and clear,
a (few) specs of bits floating about but not much.
did have hot air from heaters
not changed stat before or had new rad.


Think i must not have had bottom hose hot enough,it was more like it was warm than red hot..

is it worth fitting new stat,and not sure how to test cap?

[widdowson2008]

Think i must not have had bottom hose hot enough,it was more like it was warm than red hot..

is it worth fitting new stat,and not sure how to test cap?

If you don't know how old the stat is, then change it - no question.
When you take the old one out, take some pics of it and post them up. Pics could tell a story.
Bottom hose needs to get HOT - not just warm.

As far as testing the cap is concerned, just buy a new one (1.1bar). Far easier.

pm sent

[daveblueozzie]

Make sure you get a genuine Mazda stat not a copy one . worth the money around £16.
When you drop the coolant and change the stat, give the radiator and as many hoses as you can a good flush out with water, you might have dislodged some gunge when you did it last time, maybe causing a slight blockage some where.
Take your time bleeding the engine its not a quick job.

[chipvan]

super big thanks guys..could be light at the end of the tunnel!!

where can i get genuine mazda bongo bits from,the shop is out of stock at mo.

[widdowson2008]

I got my stat and cap from the local Mazda/Ford dealer. Do you have one near?

Check that the cap is fixed properly and not cross threaded. Easily done!!!!
This would cause the tank to erupt. Been there - Done that. (along with many others)

Upside is - it will cost absolutely nothing to fix.

[chipvan]

would like to say a BIG BIG thanks to you all,its been a stressfull week...

but ... now all is good, got father in law to help ,did it on his drive...on the flat this time.

got the bottom hose really hot by quite a bit of reving up,made sure all hoses were hot got every single bit of air out..coolant clear as a bell ..see right through it .and was able to see bubbles coming out .

when stat closes as it all cooles i reved up again to get temps up so stat was open...then saw more coming out..

The whole process took about 1.5 hours (just to be sure!)

At the end of the bleed only a flow of clear coolant came back up the funnel...



All i would say to anyone who tries this is dont rush it!!! its not hard just not a lunch break job .....



Thanks again off for a beer!

[daveblueozzie]

Make sure you check the coolant for a few days, just to make sure, you may have to top up a little.

[chipvan]

Great thanks will do..

[chipvan]

Oh no!!! its done it again this morning,didnt over heat but level went high..

weird as last night i went for miles after the bleed.

Ive got a thermostat and cap for tank on order for monday...


Just dont get it why its like this in the morning but last night it was fine and dandy???

really bled well,with nothing coming out but clear flow of coolant.....

I wonder if it is a cap issue as i toped it up this morning by less than half a cup to just above the screw mark on coolant alarm,maybe as other said i could have not put cap on right,...mmmmm

[widdowson2008]

Oh no!!! its done it again this morning,didnt over heat but level went high..

weird as last night i went for miles after the bleed.

Ive got a thermostat and cap for tank on order for monday...


Just dont get it why its like this in the morning but last night it was fine and dandy???

really bled well,with nothing coming out but clear flow of coolant.....

I wonder if it is a cap issue as i toped it up this morning by less than half a cup to just above the screw mark on coolant alarm,maybe as other said i could have not put cap on right,...mmmmm

CAP - change it before you do any damage - cheapest option and all the signs. If the cap isn't sealing, then the coolant will boil at a lower temperature. Sounds as though that is exactly what's happening.