overheat while stationary, thermostat?

[missfixit70]

Right, heres an update, Haydn it looks like you were right, ive back flushed everything, i then re-bled the system exactly the way described on BF, the temp stayed at eleven oclock even at 2500 revs for 6 mins, i must admit there was some rusty coloured coolant when i backflushed but after about 30 mins it ran clear, i then took her for a 10 mile ride to get some antifreeze, and ten miles back, there wasnt any coolant loss through the expansion tank, or any visible leaks, i believe my problem was caused by an airlock, although i have been pm,d by another bongoer who had the same symptoms and sadly it turned out to be a new head, im not the main driver of our van my wife uses it very little, short journeys mainly, she has noticed that it has lost coolant and has just topped it up as normal (as i would have done), not knowing that loosing just a litre may introduce air into the system is something i think many owners dont know? I am today gonna purchase haydn's alarm, that way we wont asume that theres enough coolant.

As Haydn says, find out why, you shouldn't need to top up a bongo's cooling system, it's escaping somewhere. No such thing as topping up as normal.
Check all your hoses, radiator, etc, possibly just a pinprick, look for staining indicative of a leak, bulging hoses. Hope you haven't done any damage Bongo cooling system is well known for it's cooling system "foibles", it seems to be one of the main topics for discussion on here in techie.

[nigelginny]

Another update, have now bled the system again! this time reading the helpfull pages on BF , looks like ive never bled the system correctly since ive had the beast , anyway managed to get all the air out (TWO HOURS OF REVING AND IDLING! eventually though no bubbles). I spoke to Haydn on the phone and he says it sounds like ive now bled her correctly , and ive just paid for a coolant loss alarm, cheers again Haydn and all that helped, hopefully ive not caused any lasting damage.

[mikeonb4c]

Another update, have now bled the system again! this time reading the helpfull pages on BF , looks like ive never bled the system correctly since ive had the beast , anyway managed to get all the air out (TWO HOURS OF REVING AND IDLING! eventually though no bubbles). I spoke to Haydn on the phone and he says it sounds like ive now bled her correctly , and ive just paid for a coolant loss alarm, cheers again Haydn and all that helped, hopefully ive not caused any lasting damage.

Good news. Fingers crossed all will be fine. Much cheaper than my offerings too

[nigelginny]

Well looks like ive still got a problem ive fitted the low level alarm, we have been driving the beast around all weekend with no signs of overheating and no loss of coolant, then out of the blue this afternoon just after we got back from a short trip, i went to move her to a better parking space then noticed a large cloud of white smoke from the exhaust, i left her running for about 10 mins and the temp started to rise and with coolant leaking out of the header tank pressure pipe, i now suspect the head gasket and maybe the head

[haydn callow]

Are you sure you have bled all the air out ?? if you have then I fear you could be right about the Head/gasket

[nigelginny]

I thought i had, im gonna do it again tomorrow morning. i hope im wrong about the head but i think i would be very lucky to get away with just air in the system after she overheated by so much,

[haydn callow]

I think your right....Make sure the garage you go to knows Bongos......If they replace the head make sure they "true up" the top of the block before fitting a new head.

[nigelginny]

Thanks Haydn, any idea of cost for new head gasket inc fitting? i guess its gonna be around £1000 with the head.

[bigdaddycain]

You may have got away with just needing a new cylinder head gasket nigelginny, but it's unlikely not to have warped the head i'm afraid...

[bigdaddycain]

Thanks Haydn, any idea of cost for new head gasket inc fitting? i guess its gonna be around £1000 with the head.

It wouldn't be that kind of money just for a new head gasket, but it would be that kind of money with a new head and gasket, with all the labour involved, plus parts.

[nigelginny]

Thats what i thought ,hopefully its just a gasket but ive got to think the worst, i will bleed the whole system again tomorrow even though im pretty sure its not air, i think we drove around about 200 miles this weekend without any probs, its just the white smoke that makes me suspect the worst, anyway i'll keep you posted how things go, thanks for all the advice, and thanks haydn for getting the alarm to me so quickly.

[bigdaddycain]

Are there any other telltale signs NG? Mayonnaise under the oil-cap? or on the end of the dipstick?

[nigelginny]

There wasnt when i bled it on friday, im asuming that air is getting into the cooling system via the head, over pressurising it, and forcing the coolant out of the header tank, im not sure if this is the case but am trying to work out why the cooling system seems to be over pressurised if that makes sense?

[francophile1947]

It seems funny that you can drive 200 miles with no problems Are you sure it's not just a faulty cap? - coolant will boil at a lot lower temperature if there's less pressure in the system.

[nigelginny]

Thats a possibility, anyone know the halfords part no, it does seem funny that we drve for nearly 3 hours without overheating! someone else said that the thermostat can take forever to open, im wondering if mine did? it looks pretty difficault to replace.