Calling all gurus, especially cooling system

Technical questions and answers about the Mazda Bongo

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langtoftnick
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Calling all gurus, especially cooling system

Post by langtoftnick » Mon Jul 27, 2015 8:04 pm

Another cooling crisis. This time from cold after about 10 miles coolant gushing out of the header tank over flow. After 3 further miles towards home ending up to 99 degrees and a callout of our neighbour with a tow bar was required.

Theories:

Blockage causing over pressure.
Head gasket failure pressurising system.
Minor leaks over a period of time causing air build up eventually causing airlock.

Refilled and bled:
The water pump is pumping
The thermostat is opening at 83 and rad hoses getting hot
Fan cuts in at 94
After three hours idling never went above 94
When revving with funnel attached coolant rushes up into the funnel and even after said three hours of bleeding there were some massive burps throwing scalding water everywhere.

Any other theories and anyone living in the stamford, market deeping, peterborough area who would be prepared to cast their eyes over it and provide a second opinion? I would be eternally grateful.

Btw 2.5 w diesel turbo

Thanks!

Nick
windywatson
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Location: Lincoln

Re: Calling all gurus, especially cooling system

Post by windywatson » Fri Jul 31, 2015 1:35 pm

Hi,
Plenty of owners out there that will have more experience with coiling issues of this type than me, so I'm sure you will get some help.
However it does sound to me as though it is combustion gases getting into the cooling system. So could be head gasket problem. What makes me think this is that the symptoms you describe seem to get worse when the engine is under load. In creased load would have the effect of increased pressures, there by passing more gasses by the fault.
Hope you get a resolution to this soon that's not to costly for you.

Cheers
Windy-Watson
2001 V6 Tin Top
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mikeonb4c
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Re: Calling all gurus, especially cooling system

Post by mikeonb4c » Fri Jul 31, 2015 4:37 pm

windywatson wrote:Hi,
Plenty of owners out there that will have more experience with coiling issues of this type than me, so I'm sure you will get some help.
However it does sound to me as though it is combustion gases getting into the cooling system. So could be head gasket problem. What makes me think this is that the symptoms you describe seem to get worse when the engine is under load. In creased load would have the effect of increased pressures, there by passing more gasses by the fault.
Hope you get a resolution to this soon that's not to costly for you.

Cheers
It does sound like this is a possibility. A compression test of the cooling system should hopefully confirm it or eliminate it from enquiries. Good luck, keep us posted, my sympathies as I had to have a new head this year as it went for no obvious (lumpy start and steamy/smoky exhaust after start up were my symptoms - compression test didn't show up a problem).
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