Temp alarm following coolant change

[cobbdu1]

We had our MOT last week, and we asked the garage to change to coolant completely, following advice from this group. They replaced the green coolant that was there since we bought our Bongo (an import) and put in red coolant instead. On our first outing the temperature sensor I installed last year reached 100C and the alarm went off. This has never happened before. The coolant levels are high so it doesn’t appear to be leaking. Can anyone offer any advice please?

[Bob]

Which engine do you have?

And did you use a Bongo Savvy garage, ie, was it bled properly?

[cobbdu1]

2.5D

I believe they are Bongo savvy. They’ve dealt with a lot of Bongos as they were recommended by someone on a forum and got loads of business as a result. Though they’re not Bongo specialists. They’ve just seen a lot of them.

[cobbdu1]

I’ve contacted them and am dropping it off tomorrow. Hoping it’s something like an air lock that is easily remedied.

[Bob]

Fingers crossed. [-o<

Garages recommended by the crew here are generaly pretty good, can't fault them taking a look.

[haydn callow]

Different coolants have different cooling abilities....
100c isn’t silly high depending on what you were doing.
What temps were you recording before, under the same conditions.

[cobbdu1]

The alarm has got to 100C once before, after a long uphill, and it quickly cooled down once we got on the flat with the faster air cooled things down a bit. Yesterday’s driving was normal.

Meanwhile, I took the Bongo to the garage this morning. The alarm was sounding even though the temperature was below 10° so I figured the alarm needed resetting. In the garage they said the coolant level had dropped significantly and so they suggested that the airlock might have removed itself overnight. When I checked the coolant yesterday, whilst the temp alarm was going off, it was well above the fill line. Given what the garage said it would suggest that the coolant level did indeed drop and the alarm I heard this morning was actually the coolant alarm instead (it sounds the same as the temp alarm). So hopefully the problem has corrected itself. The garage said that they think it will be alright but to take it back to them if we have any issues.

[Bob]

Sadly, I've never heard of an air lock (in a Bongo) 'removing itself'.

[haydn callow]

After a bleed the coolant level often drops .

[Bob]

True Haydn.

What would be a normalish amount, would you recon?

Valuable info for us all.

[haydn callow]

Half litre or a pint’ish

[Bob]

Thanks, that is useful.

[haydn callow]

I think the amount depends on how successful the bleeding has been, I bled loads of bongos and had to top up very little, but many peeps stop very soon after the stat opens. This can leave air in odd corners which is expelled after a day or so and drops the coolant level in the tank.

[JulesMartin]

previously before i did my head when I was bleeding I'd stop pretty much after the thermostat opened and always had to top up the next few days but I put that down to the head being suspect, which to be fair, it was. Since doing the head on the two occasions where I've had to bleed it out again (metal heater hose replacement and heater hose) I bleed out until the fans cycle a couple of times. probably takes an hour in all but I've found much more success with the level staying constant in the header tank. I'm thinking that in this case the garage is on a time restraint to get the job done and hoped that it would settle itself down after a couple of days. Bongo's don't play like that do they!