Overheating - help!

[Slybacon]

Okay folks here are the facts:

1. Bongo rad fans are running after very short trip/period of time.
2. Inside the van is getting hot - handbrake is hot, drivers seat is hot.
3. Bottom hose from rad is cold(top hose is hot)
4. Temp gauge is sitting at 11 o'clock
5. No discernable loss of coolant.

I've tried reading the numerous previous posts and I've got some ideas but would like some help from those of you who have experience.

Here's my plan of action - tell me what you think.

1. Drain coolant and test thermostat - I'm thinking that this is the most likely cause(?)
2. If stat is okay, flush rad - maybe get it tested or changed?
3. erm............

Any advice would be appreciated. We are planning on camping in France for 2 weeks at the end of the month and we need her cool

[lizard]

There is loads of stuff on the forum about this problem have a look there and don't drive it again untill you are shure it's ok.

The temp gauge will stay at 11:00 when boiling over, too late then.

As you say it might be thermostat or blocked rad.

Peeps reckon if the rad is blocked its best to buy a new one.

There is other stuff, but would rather wait for others, as I wouln't want to give usless/wrong information.

There will be a load of experts here soon to tell you the correct procedure

[mikeonb4c]

This is not really an answer to your question, but something to consider anyway.

I found it was dead easy to fit a separate feed to the engine bay scavenger fan, with a switch on the dash, so I can pull air through the engine bay whenever I like. There is a temp sensor (as you seem to have discovered by the fact your fan is on) that will cut in in extremis, but I think the bay (and the cars occupants) will come to no harm in having airflow through the engine compartment in the interest of coolness.

But you need to get to the bottom of the problem, that's for sure. Good luck and keep us posted.

[The Great Pretender]

Okay folks here are the facts:

1. Bongo rad fans are running after very short trip/period of time.
2. Inside the van is getting hot - handbrake is hot, drivers seat is hot.
3. Bottom hose from rad is cold(top hose is hot)
4. Temp gauge is sitting at 11 o'clock
5. No discernable loss of coolant.

I've tried reading the numerous previous posts and I've got some ideas but would like some help from those of you who have experience.

Here's my plan of action - tell me what you think.

1. Drain coolant and test thermostat - I'm thinking that this is the most likely cause(?)
2. If stat is okay, flush rad - maybe get it tested or changed?
3. erm............

Any advice would be appreciated. We are planning on camping in France for 2 weeks at the end of the month and we need her cool

It is possible the head is full of air. Have you purged it?

[Aethelric]

Okay folks here are the facts:

1. Bongo rad fans are running after very short trip/period of time.
2. Inside the van is getting hot - handbrake is hot, drivers seat is hot.
3. Bottom hose from rad is cold(top hose is hot)
4. Temp gauge is sitting at 11 o'clock
5. No discernable loss of coolant.

I've tried reading the numerous previous posts and I've got some ideas but would like some help from those of you who have experience.

Here's my plan of action - tell me what you think.

1. Drain coolant and test thermostat - I'm thinking that this is the most likely cause(?)
2. If stat is okay, flush rad - maybe get it tested or changed?
3. erm............

Any advice would be appreciated. We are planning on camping in France for 2 weeks at the end of the month and we need her cool

Your plan of action seems good to me

1. Bongo rad fans are running afTter very short trip/period of time.

Coolant and/or engine must be hot to switch on fans

2. Inside the van is getting hot - handbrake is hot, drivers seat is hot.

Engine is hot, sounds like the scavenger fan is not working - although this should not effect the engine much. If there is lots of heat from the heaters then the coolant is getting hot and your pump is working.

3. Bottom hose from rad is cold(top hose is hot)

If the fans are coming on the bottom hose should be warm as the stat should open before the fans switch in.

4. Temp gauge is sitting at 11 o'clock

Thats usual - the standard guage is crap. It will work properly if you fit a mason alarm

5. No discernable loss of coolant.

Thats a good sign - assuming you mean that the level in the tank isn't going down.

It sounds like no flow through the radiator and the stat - the stat is a good place to start.

Good luck and let us know what you find

Dave

[Slybacon]

Thanks folks. Will do and keep you'all posted.

[haydn callow]

Could well be nothing wrong.
How long have you had the Bongo ?
Is this somthing that has just happened ?
Has anyone been messing with the cooling system ?
Are you loseing coolant ?
Do the fans come on even with the heating/aircon off ?
If you can answer these ????'s we may learn somthing

[Slybacon]

To answer your questions:

Could well be nothing wrong.
How long have you had the Bongo ? 6 months
Is this somthing that has just happened ? Yes, just started yesterdayHas anyone been messing with the cooling system ? No. I haven't been using the van much recently though. Just short trips (2 miles) to the train station and back.Are you loseing coolant ? No. Level seems fine.
Do the fans come on even with the heating/aircon off ? Yes.
If you can answer these ????'s we may learn somthing

Cheers

[haydn callow]

O.K. I would start by bleeding the system. I use the "see saw" method with good sucess.
If you need any info on this ...give me a ring 01458 270230
However it is important you bleed long enough to get the stat open and bottom hose hot.
If you have a blockage this is risky so do get someone to keep a eagle eye on the temp gauge. The slightest movement above 11 o'clock stop at once.
Expect bleeding to take about 30/40 mins ..stat should open in this time.

[Slybacon]

I'm a wee bit confused Haydn. Do you mean that I should use the see-saw method to bleed the system without first draining the coolant?

My thought was to drain the coolant, remove the stat and check it by heating it in water to see if it opens at the correct temp. If faulty, replace it. Is this unnecessary then?

Cheers

[haydn callow]

Personally I would try and bleed it now. If you cannot get the stat open/bottom hose hot then drain and flush. That is the course I would take. The risk is ..if you do have a blockage then you could overheat the engine.
If you want to check the stat first then you might as well drain/flush. If you take the stat out and test it, I would put a new one in whatever the result of the test.

[Slybacon]

Thanks Haydn. I think I'll drain and flush and test the STAT. Probably won't do any harm to try.

Cheers

[Slybacon]

Drained coolant and checked stat - seems to be opening fine. I didn't have a thermometer but it opened in the pan just before the water started to boil and bubble - so my guess is that it is okay.

Next job will be to flush system. I'm going to have a wee search on the forum for the best method first. If anyone has the time to give me some advice I'd appreciate it though.

[mikeonb4c]

Out of interest Sly, was the coolant that came out nice and clear or was there any hint of rustiness in it?

I think (like Haydn) that I'd put a new thermostat in regardless of test. When I changed mine the time to get engine up to temp went down from 10 mins to 5 mins so I think they can get 'tired' even though still working. They're cheap anyway and you if you have to go to the hassle (and expense - antifreeze costs) of draining the system it's good to know it has a new thermostat.

Keep us posted and good luck.

Mike

[Aethelric]

Drained coolant and checked stat - seems to be opening fine. I didn't have a thermometer but it opened in the pan just before the water started to boil and bubble - so my guess is that it is okay.

Next job will be to flush system. I'm going to have a wee search on the forum for the best method first. If anyone has the time to give me some advice I'd appreciate it though.

I used a slight variation of the see saw method. I did not have a funnel so I used a big pyrex jug with coolant in it. I put the end of bleed hose below the surface. With the engine running, and the header cap off, I kept lowering the jug so that coolant ran into the jug, bringing air with it, then lifting the jug so that the coolant siphoned back into the engine. This has to be done until the thermostat opens and by that time the coolant is very hot so you need to be careful.
When the bubbles had stopped coming out I raised the jug to siphon most of the coolant back into the engine. Then I added some cold water to the jug so it was cool enough for me to put my hands in and pop the bung into the end of the bleed hose.
Then I went for a blast, keeping a close eye on the guage - no problems.
Then, using the idea that any small amount of air in left the system would have collected at the top of the engine, I left it overnight, and did it again first thing the next day with the engine cool and not running (a five minute job). I got out a few very small bubbles.
I did it all single handed, but it would have been easier with two folk.

Next time I do it I'll arrange a method to hold the jug at a height about the same as the header tank so i can rev the engine more easily. Sly, if I had taken out the stat, I would have put a new one in - thats on my list of things to do.

Hope this helps

Dave