Let sleeping coolant dogs lie?

[Lewy]

I've had my Bongo for getting on for four years now and it has been my daily driver all that time - expensive yes and possibly an indulgence too but what the hell. I've got a Mason alarm and an engine saver alarm fitted too and on my daily drives I can pretty much see a very consistent pattern of temp rises and falls - and can see the thermostat is working well too respond to extra demands - hills etc.

Yesterday had to drive to Taunton and noticed on the motorway the temp was fairly high - especially on long drags up inclines. On the way back the very steep stretch of the A38 where the Plymouth and Torquay traffic splits really caused the temp gauge to go high enough to give me a single pip and set the mason alarm off - got up to 98 I think. No boiling or anything or loss of fluid. Then it all settled back down. This has only happened once before on Dartmoor - again labouring up very steep, long hill in very hot weather. It could be that the alarms are all set too low?

I've suspected for some time my engine seems to run a bit hot- but have never been sure really and am basing it solely on gut feeling. So the questions are should I go for a coolant change and good old back flush - its never been done or leave it? Also I don't have access to a hose etc for the flush so would be looking for a garage to do it - I'd use Dart Motors in Totnes - what would be a fair price for the job? AND should I change anything else at the same time - stat - top hose etc?

Any thoughts?

[nfn]

I'd do a visual check and feel up of all of the coolant hoses if I were you. Any that look cracked, are swollen or soft should be replaced when the backflush is done. I personally would not change the stat if it appears to be working fine.

[apole]

Hi,

Good you have the alarms so you can see this stuff.


I'd go for a good visual inspection, what is the coolant in there like, is the header tank clean etc?

Also when was the coolant last changed, it should normally be done every 2 years as after that is looses it's anti corrosion properties etc.

Alans Vehicle Services is down your way I think, give him a call as he's got a very good reputation and regularly contributes to this forum.

[bigdaddycain]

It sounds to me like you have the mason alarm set just right, it has sounded just the once, right on the limit of everyday use of your bongo, in the highest extreme you are likely to encounter.

I've had mine go off just the once too, whilst climbing what seemed to be a 4 million mile ascent in scotland last year, i adjusted the mason alarm up half a notch for the remainder of that journey, then reverted back to number 4 when i returned home.

[Veg_Ian]

You've said you have had the vehicle for 4 years but never changed the coolant? I would be changing that now, worries or no worries. If you don't have the facilities to do this yourself then considering a dealer will charge £40 for a Yaris (quote from another forum) then expect a tad more for a Bongo but less from an independent garage. Wheelquick appear to be a good baseline for prices so I'm sure someone from t'other side of the Pennines can give you a better idea of a fair price. Do make the garage very aware of the special instructions needed to prime the Bongo's coolant system though.

[mikeonb4c]

Fit a new thermostat while you are changing the coolant and see what benefit that brings. Also backflush the radiator (there was an interesting post on here a while back about someone who a Bongo dealer - Hillside was it? -) got an old radiator cleaned out by a specialist company to removed clogging deposits (a sort of dynorod for rads). Ultimately, maybe the radiator is losing efficiency through clogging?

I'd take action now to reduce a hot running engine and accelerated wear etc.

Good luck and keep us posted Lewy as its an interesting one this (4yrs reliable runing etc.)

Mike

[dobby]

I had an over heat a couple of years ago, did a flush and bleed etc and it ran ok for two years but hotter I think than before. However recently it dropped it's coolant following a rusted core plug (My fault - crap anti-freeze etc.) The core plug was sorted but coolant was being lost via the breather tube. It went back into the garage and it was found that the Thermostat was knackered - maybe because it stood dry for a bit but I also reckon it was on the way out.

My advice is that BDC is right,if the mason beep was an unusual event then keep an eye on it. If however, you can replicate the problem 70+ etc then get a flush and reflll done (shold be every two years anyway) if that fails then do the stat etc?

[Lewy]

Flush and coolant change it is then. Will post up to see if there is any difference - hopefully for the better!