Coolant and overheating strangeness

[freakrhw]

Hi Folks,

I had a coolant leak a wee while ago, it was down to a issue with one of the pipes. I managed to get it fixed and when I took the bongo out again it seemed fine for a short while but then the temp gauge started to rise again. I managed to get it home with some stopping and starting but something odd happened.

As I was limping home the temp would rise up as expected and then I would park up and it would drop again. However when I was just outside town I pulled over as usual and sat for a bit but when I drove off again the temp needle didn't go above half (this is where is usually sits when driving for me)

The funny thing is this happened previously when the initial leak occured.....at the exact same spot!

The difference was this time there was no steam and no coolant leaking out of the van. Would anyone know why it might be overheating one minute and not the next?

There were no visual signs of overheating that I could see this time, the fan came on but I am guessing that's controlled by the temp gauge....

Could this be caused by a bleeding issue or something like that?

Thanks for any pointers...

Cheers

[g8dhe]

You don't say what engine ?
Normally over heating problems are caused by either loss of coolant which can be quite obvious or air blocks circulating around the system blocking it at various points and then being forced onwards to another part of the engine until they work there way out to the de-gassing tank where the level of coolant will then drop and the gasses/air will stay in the tank as its the highest point in the system. The air maybe left in the system when it was last refilled and not correctly bled out of the engine or there maybe a pin-hole leak that allow coolant to be ejected when hot and under pressure and then sucks in air as the engine cools down, this air then gets to sufficient level over several heating cycles to cause the problems again.

[Northern Bongolow]

Sounds like it wasn't bled completely when the pipe was swapped. Top it to the correct level when cold and see if it holds its own over a few local journeys.

[oibaf]

Hi Folks,

I had a coolant leak a wee while ago, it was down to a issue with one of the pipes. I managed to get it fixed and when I took the bongo out again it seemed fine for a short while but then the temp gauge started to rise again. I managed to get it home with some stopping and starting but something odd happened.

As I was limping home the temp would rise up as expected and then I would park up and it would drop again. However when I was just outside town I pulled over as usual and sat for a bit but when I drove off again the temp needed didn't go above half (this is where is usually sits when driving for me)

The funny thing is this happened previously when the initial leak occured.....at the exact same spot!

The difference was this time there was no steam and no coolant leaking out of the van. Would anyone know why it might be overheating one minute and not the next?

There were no visual signs of overheating that I could see this time, the fan came on but I am guessing that's controlled by the temp gauge....

Could this be caused by a bleeding issue or something like that?

Thanks for any pointers...

Cheers

Sounds like either a dodgy temp gauge, or more likely, there's air in the system (if it's a diesel or V6, these don't self-bleed like the 2.0 petrol does). You'll need to bleed it out before going any further really. Maybe consider a self-bleed kit (Rusty's Bleed Kits, do a search on facebook) if you're not confident about the usual bleeding procedure for these units!

Hope you get it sorted .