Bongo running hot! Help please.

[mikelamb]

Hi All,

Can you give Me some help with this problem please.

My Bongo seems to be running quite hot. (not the first to make that statement I know!)

The temp gauge needle is just about at 1:30 on the gauge (not far off the first white line on times) I have a mason alarm fitted.

The cooling fans are pretty much on the go all of the time after she has reached her running temp.

I carried out a full coolant change and flushed the rad. But this has made no differance.

The van is running really well but for this, and has been like this for some time. But I do think that it is hotter than normal.

Just wondering what to do next or just keep going and fingers crossed! I have the mason alarm set at just above 5, any lower and it alarms.

Be really greatfull for any suggestions,

Mike.

[missfixit70]

Thermostat?

[mikeonb4c]

I don't have a Mason alarm but those who do may say the position is not too abnormal. However, fans running all the time doesn't sound right. If it were me, I think I'd be wondering about the thermostat first. Is the bottom hose getting hot when engine is up to temp and fans are running. If it isn't then thermostat has to be suspected of not opening properly I reckon.

What about header tank. Any signs of staining? Coolant - is it clear? If not this might point to badly maintained coolant system and resulting damage to components.

Are you OK with DIY mechanics? If so, maybe drain system, fit new thermostat (asuming bottom hose test had confirmed it was cold during normal running), refill temporarily with water only and bleed properly. Test run it and see if things have improved. If they haven't then its on to considering if water pump is not working properly so consider replacing. If tests show no improvement, then its on to radiator as perhaps being blocked / tired.

Someone else recently found that a new radiator (buy a good one, not a cheap one off ebay) got the Bongo running much better.

The thing with replacing these items is even if only one of them is the prime cause of your trouble, they will all benefit cooling system by improving its performance.

Wait and see what others say about the above before deciding on best course of action.

Don't leave 100% water in the system for any length of time before replacing with 50/50 antifreeze/anticorrosion mix. But no point wasting money on 50/50 if you are about to drain and waste it all over again as you tackle various components.

Good luck - keep us posted

[mikelamb]

Many thanks for your replys.

I have just replaced the thermostat during the coolant change so I think it rules that out.

The water that came out of the system looked very "rusty". Perhaps I need to think about a new rad for it.

After I stop, if I then turn the egnition back on the cooling fan is going. It might be Me but it also feels fairly hot in the "cockpit", if you know what I mean.

I'm just losing a bit of confidence in it, and each time we go out I am constantly watching the temp gauge! Not very relaxing to be honest.

Thanks again,

Mike.

[The Great Pretender]

The only time my fans did as yours are was after working on the cooling system. Mine was due to air in the system.

[Bob]

Many thanks for your replys.

I have just replaced the thermostat during the coolant change so I think it rules that out.

The water that came out of the system looked very "rusty". Perhaps I need to think about a new rad for it.

After I stop, if I then turn the egnition back on the cooling fan is going. It might be Me but it also feels fairly hot in the "cockpit", if you know what I mean.

I'm just losing a bit of confidence in it, and each time we go out I am constantly watching the temp gauge! Not very relaxing to be honest.

Thanks again,

Mike.

This alone would be normal,as the water pump is not running and the block dumps heat into the coolant.

Try it with any car, run up to temp, stop for a few minutes, turn ignition back on, and the temp gauge will have risen a lot.

Other probs need investigation as recommended.

[mikeonb4c]

The only time my fans did as yours are was after working on the cooling system. Mine was due to air in the system.

TGP has spoken - listen up

But rusty coolant does make me think (like you) that a new rad. might be in order. I guess try re-bleeding first then move onto the other stuff

[Mike Jill and Emily]

I swapped my rad a while ago as under load (hills etc) the temp got to max (Mason alarm fitted). I checked the rad by filling it with hot water from the kettle and found that only the middle section got hot - I tried radflush etc but with little success and therefore got a new Mazda Rad. It turned out that the old rad was probably 75% blocked - the difference is amazing now, temp can get to just over half way when towing (small trailer) up hill in hot weather

If you are happy with the bleeding procedure then try draining the system, see how fast water will go through the rad - and then fill it with hot water and see what is hot!!

An easier way is to try to feel the front face of the fins on the radiator after a run - it should be a similar temperature all the way across and get cooler towards the bottom. I found that mine was hot in the middle but cold at the sides.

Hope this helps - although I am a relative noob to the Bongo

[Doone]

I noticed that in a previous post, you said you'd put K Seal in the bongo:

Hi All,
Would really like your thoughts on this one. I recently added a can of K seal to the water system on my Bongo. I did it as a preventetive measure as it says that it stays in the system and blocks holes that appear in metal pipes ect. After adding it I have noticed that the mason alarm comes on more often and the needle on the temp gauge is slightly higher than usual! Can't decide on whether to drain the system or not. I would appreciate any advice on this from you please.
Thanks, Mike.

Did the temperature gauge read high before you added the K Seal? If not, I think the current problem may be related to the K Seal.
Did your bongo have 'rusty water' before you added the K Seal? If not, it's possible that the 'rusty water' is the K Seal still in the system. Did it come with any instructions for getting it out of the system?

[missfixit70]

That could explain a lot, good detective work Lorna Wonder if a few hours spent with a 2 part chemical flush such as Holts would shift it, certainly removed a load of crud from mine.

[mikeonb4c]

That could explain a lot, good detective work Lorna Wonder if a few hours spent with a 2 part chemical flush such as Holts would shift it, certainly removed a load of crud from mine.

Oh crap (in the system). That is indeed good detective work Lorna and there is a depressing likelihood this is more than coincidence. I reckon damage may be effectively irreversible if the K seal stuff has set and clogged the pipes. New components (rad. in particular) may well prove wonderfully curative

PS - presume new thermostat was after K seal had been used and settled else it too may be involved in gungedupedness

[mikelamb]

Hi,

The k-seal was flushed out soon after adding it. Perhaps like suggested the k-seal had already gone to work on the rad ect and it is irreversible.

Just got back from work and checked the bottom hose (the one low down to the right of the rad as you look in) It was cold to touch, I'm going to run the van for a while longer as it had been on stop for about 45 min before I checked it. Should it be warm?

Other than that I will look for a rad and try to rule that out.

Thanks for your help,
Mike.

[mikeonb4c]

Hi,

The k-seal was flushed out soon after adding it. Perhaps like suggested the k-seal had already gone to work on the rad ect and it is irreversible.

Just got back from work and checked the bottom hose (the one low down to the right of the rad as you look in) It was cold to touch, I'm going to run the van for a while longer as it had been on stop for about 45 min before I checked it. Should it be warm?

Other than that I will look for a rad and try to rule that out.

Thanks for your help,
Mike.

I think it must be at least warm if things are working properly, but to test properly you need to have been on a decent run to get things up to temp. and ensure thermostat has opened - assuming it does wha it is supposed to do. Also, feel bottom hose (from memory I think thats the hose - what other hose could it be!?!) immediately after stopping as stationary coolant in it will cool otherwise.

I'm suspicious of K-seal and stuff (though I'm no expert so don't take my word on it) as it seems to me there are few miracles under the sun. If it is intended to stop things up then I reckon in works by (1) finding its way into gaps and (2) growing/accreting in places where it can get a hold. Slightly furred or corroded narrow bore rad. pipes might fit under (2). Just a guess though.

[francophile1947]

I've never tried K Seal, but I've used Radweld and Bars Leaks with no problems - not for many years though. They certainly didn't block anything apart from the leak they were supposed to. If memory serves me correctly, they shouldn't set unless exposed to the open air.

[mikeonb4c]

I've never tried K Seal, but I've used Radweld and Bars Leaks with no problems - not for many years though. They certainly didn't block anything apart from the leak they were supposed to. If memory serves me correctly, they shouldn't set unless exposed to the open air.

I guess its one of these tricky areas. Were the pipes on the ones you tried it on in better nick (no furring) or maybe of bigger bore (older technology) than this particular Bongo. Who knows. But clearly the stuff can't be causing bad side effects on a regular basis or it'd be a banned substance