Tracing a coolant leak ?

[alze]

Hiya,

I've recently had my Bongo cylinder head changed over, and as part of that put the haydan alarm in for head-temp and low-coolant levels. I had driven it just over 100 miles, and now its complaining about low coolant A visual check is difficult due to the aged with the opaqueness of the header-tank but I do trust that the alarm has been fitted properly and is reporting correctly.

I am wondering why my mechanic, who does have a good reputation with bongos and has done a good job on the cylinder head, hasn't spotted this leak, and I'm now left without my bongo when I really wanted to use it ! I've already dropped him a line about bringing it back for it be checked over.

Is there some way i can trace the leak myself ? Any tips really appreciated, i just want to enjoy my bongo ! What can I do to help myself/assist my mechanic ? its cost a few quid already, but really glad the alarm saved the day on the cylinder head.

Kind Regards,
Alze
https://bongo.knipmeyer.co.uk/

[g8dhe]

Its quite possible that it isn't actually low, when new fresh coolant is added it has chemicals in it that deposit on clean metal to prevent corrosion, this includes coating the sensor screw and hence after new coolant is added its quite likely that a week or two after the alarm will start going off. Leave the cap in place also make sure its quite cold as well, and simply unscrew the sensing screw, quick wire brush of screw and put it back in again, that is often the problem resolved, it won't happen again until the coolant is changed in 5 years!

[alze]

Thanks g8hde,

I got my mobile-phone torch/flash behind it and with my weight gave the bongo a good roll around, i could then see the water level changing as I moved the bongo around, and could confirm it was just below the lower limit.

My garage have been excellent in responding to my email query as well, saying it could be settling down, so I have topped up with distilled water for now and will monitor the situation. The alarm has is now silent since filling back up, and thankfully prior to the refill the water level hadn't gone anything more than a few millimetres below the 'low' level, but enough for the alarm to go off.

I'm still not risking the 300+ mile trip i was planning this weekend with it, but am glad of the support of the forum and my mechanic as well, feel I am in good hands and will get this sorted one way or another.

Kind Regards,
Al.ze

[haydn callow]

First get the level in the tank correct...do this by dipping a clean wooden stick vertically into the tank when all is cold, it should show about 2 centimetres of coolant on the stick.
Your garage is correct , things do settle at first and everything is probably o.k. And you have your alarm ac backup....if it goes off just put a half pint in after letting it cool down.
New coolant can coat the sensor screw as mentioned above, normally red 5 year coolant. Just do as suggested if this happens.

[Roy748]

Hi
I assume you have a diesel engine?
Juat another thought. I have a 2.0 litre petrol but experienced a similar dilemma with gradual coolant loss after a leak. Mine did settle down after around 200 miles and I believe the problem was trapped air within the heater matrix. Turn the heater onto hot and run it for a while as this will pump water throughout the system and clear the air bubbles. In this weather we don't run the heater on hot thus potentially trapping air.

[g8dhe]

Coolant is ALWAYS flowing thru the heater matrices front and rear, its the air side that is controlled with flaps to allow the air either thru the heater or bypassing the heater.

[alze]

Hi All,

Many thanks for all the responses. I've got back from my Welsh mini-holiday, albeit with the car and not the bongo, but I took the bongo for a test-spin tonight observing the water levels. All looks ok, and have a got a coffee stirrer to record the levels as accurately as I can, as I'll be taking it for another spin a bit further afield tomorrow. On tonight's drive for about 5 miles in hills/urban traffic the temp never went above 85, so reckon I'm o.k. there. It used to get alot hotter before the head change for sure !

I'm hoping as others have suggested that its just bedding in with all the work that's been done on the engine (e.g. cylinder head renewal).
Thanks to you all for the advice and positive feedback, its much appreciated.

Al.ze

[alze]

Shes all good - took her over to the garage and they was really good on putting up on the ramp in no time and giving it a good visual inspection. I even got to have a look under, not that I had any idea of what i was looking at beyond a set of wheels and prop-shaft
Seems like the bongo will get some decent use around the New Forest in the tail-end of summer at long last.
Really glad I got such a good bongo garage nearby!

[Bob]

Well done.