What should my fan be doing?

[Paul A]

A few weeks ago, a few days after having my cylinder heads done, my radiator started leaking. I assumed this was the result of the pressure that had been building up prior to having the heads done. However when the new radiator was fitted the mechanic seemed perplexed that the fan was kicking in so soon. I've had no trouble since having the radiator fitted and my temperature gauge has never been above half way even when my overflow tank was bubbling over when the gaskets had gone. From cold it seems to get up to it's normal running temperature after just a couple of miles, but I can't hear the point at which the fan kicks in.
The mechanic was worried that there was a problem with the thermostat, but surely that would register on the temperature gauge?
Is it normal or is there a problem?
We've had the Bongo for about 4 years now and it runs as great as it ever has. Just wish I could slow down the rust that's now spreading quickly.

[helen&tony]

Hi
Silly question, but have you got the aircon switched on?...that'll get the fans going (assuming that your overheating problems HAVE been cured)
Cheers
Helen

[widdowson2008]

This diagram explains (I hope) when you can expect the fans to kick in. They are controlled by the ECU via a temperature sensor mounted on the engine. The LOW speed fans comes on if your temperature gets to 96, ie when the thermostat has lost control.

edit: This is a diesel. Don't know if petrol engines are the same. Probably very similar though.

[rita]

A few weeks ago, a few days after having my cylinder heads done, my radiator started leaking. I assumed this was the result of the pressure that had been building up prior to having the heads done. However when the new radiator was fitted the mechanic seemed perplexed that the fan was kicking in so soon. I've had no trouble since having the radiator fitted and my temperature gauge has never been above half way even when my overflow tank was bubbling over when the gaskets had gone. From cold it seems to get up to it's normal running temperature after just a couple of miles, but I can't hear the point at which the fan kicks in.
The mechanic was worried that there was a problem with the thermostat, but surely that would register on the temperature gauge?
Is it normal or is there a problem?
We've had the Bongo for about 4 years now and it runs as great as it ever has. Just wish I could slow down the rust that's now spreading quickly.

Hi,do you have a diesel or v6 petrol engine.

[Paul A]

Aircon not on and have diesel van. I will have a look to see at what stage they are coming on. If they are coming on too early what is that symptomatic of? Does it mean I need a new thermostat or a new sensor? Thanks for your help so far

[helen&tony]

Hi
Before ANYTHING else, you need a pressure test. I reckon there are a number of culprits for your problem, so before spending , get a test. The problems could be:
hoses, metal pipes leaking, stat., sensor, small leak somewhere else ...radiator or heaters, could even be that it wasn't bled properly.
It might be advisable not to use the vehicle until it's sorted...It CAN, and I say CAN indicate that you may still have a head problem, if the job wasn't done correctly...Bongos are a bit fussy, but once properly sorted, are quite reliable!
Cheers
Helen