Hi all.

Got back from work the other week and smoke was coming from the front of the van.

I popped the hood and had a look , seems the smoke was coming the top of the rad.

I know its bad, but money is tight, but i put some rad weld to hopefully seal it, But i got back again today and smoke/steam was coming from the same place.

I left the engine running and the fan did not come on at all to cool it down, so im thinking the fan may not be working.

I've opened the fuse box to see which kinda fuse it is, but cant work it out (which fuse is for the fan, i took a few out) And now have the little engine looking symbol red light on dash!!!

How do i check if the fan is working at all?

I can move it (when engine is off of course) does not seem stiff.

I dont wanna take it to a garage and them charge me a few hundered quid, when it could just be a fuse.

All wires look in place and seem in good condition.

Is there a way i can send power to the fuse and see if it comes on?

Any help would be great, bit worried to drive it in case it blows up, but being self employed, if i dont work i dont get paid.

thanks

:worship:

Hi.
A little more detail would be helpful, eg, year & model! Does your dash have a temperature gauge and has there been any coolant loss?

I think the first thing to do is put the fuses back! Also be clear that if the engine overheats youre looking at head gasket replacement and maybe warped head. Does it have a temperature gauge and if so use it, if it goes over 90 then you need to fix the fan even if it means taking it to a garage. Radweld will not prevent steam being escaped by the pressure release cap. Is the steam coming from the cap or the radiator headed tank?

52 reg doblo 1.9JTD (lovely dirty blue)

Temp guage never seems to go above mid way.

Fuses went back after i took them out!

Steam/smoke comes from Rad near the top.


But today, I started the van and left it running while i put a few bits into the back (must have been running idle for tops 10mins.)
Smoke (with a burning smell) was inside the cabin, and then noticed a pool of water comng from under the van.

Turned the van off, water still dripping. Looks like its the bottom of the rad (bottom left as you look inside the bonnet)

The smoke inside cabin seems to be the heater has burned out, werid as both the heater and the rad both going at same time.

Anyways got towed home as exspanstion tank kept empting !!! :bang:

So taking it now i defo need a new rad and heater motor, any ideas on cost?

cheers

I do believe Rad has completely gone. seems to be leaking water in two places. One top and one bottom!!!

New rad now need i guess.


How hard is the rad to change on the dob? does any one have any tips, and where is best place to pick one up from??

cheers

For new prices checkout
www.eurocarparts.com.
www.adrad.com

Seem to be around nifty quid.

Wait!

Before you replace the rad take the header bottle top off and fill with water. start engine see if water shoots out! I bet it will!

If you have blown your rad that is most likely because of high pressure... if so your heads gone.. putting a new rad in will not help it will blow too wasting yet more money.

wad2502 said:

Wait!

Before you replace the rad take the header bottle top off and fill with water. start engine see if water shoots out! I bet it will!

If you have blown your rad that is most likely because of high pressure... if so your heads gone.. putting a new rad in will not help it will blow too wasting yet more money.

Click to expand...

So it won't shoot out as a result of the water pump being spun then?
I also thought rad caps had inbuilt pressure relief valves?

When You first start the engine the system is unpressurised, as it heats up the expanding water pressurises the system, not the water pump.

No,
The water will not shoot out when then engine is started, if the engine is cold, unless the head is blown.

The pressure cap is there to increase the temperature at which the coolant will boil.

A good test is to (starting with a cold engine) release the cap to make sure it is unpressurised. Refit cap and start engine, keeping fingers WELL clear of the cooling fan feel the amount of pressure in the radiator pipes (thick black pipes) if the head is badly blown you can feel the pipe pressurise up. If this takes only 30 seconds or so the heads gone. If the engine gets warm / hot first then less likely the heads gone.

The main problem here is the rads blown so the system will not pressurise anyway.

The same test with the header tank cap off will show also if the heads on its way out.. constant bubbles coming from the water feed into the header tank is also a sign all is not well.

DO not do this with a hot engine!

If you release the pressure cap off the header tank while the engine is hot could get you badly burnt!

I have had a nice hot shower before now in anti-freeze / coolant by doing this. I was lucky not to get burnt..

I've filled the expansion tank with water, when i start the engine, water comes out of the bottom of the rad (bottom left) drips out pretty fast from what i can tell. It also comes out from the top of rad near the middle, but is a slow ish drip that runs down the rad.

But the rad went completely i had the rac out, they followed me part way home to make sure i was ok. After 2 miles we pulled over to check the system, he undone the expanstion tank cap, but there did not seems to be much, if any pressure there (engine way fairly warm by this point and had been running idle for a while) He said this was good, as seems like is just the rad that needs replacing.

All your help and advice is great, but now really worried this is more than just a rad that has gone.

I take it by "head" your all meaning head gasket?

Worst case how much am i looking at to fix this?

My bro said he would help me change the rad, but starting to think this may end up being a waste of time and money.

Van only worth £1500 at a push, when in good working order.

I still have the heater motor to fix, and im guessing it went at same time as rad, as its link together?

I didn't say the water pump pressurised the system, but with the lid off the header, some water will shoot out as the engine turns due to the turbulence of water being pumped around.
Also you said "The pressure cap is there to increase the temperature at which the coolant will boil."

surely the pressure cap is there to prevent the system becoming over pressurised & splitting hoses, rads etc, it is the increased pressure that increases the boiling point of the coolant.

I have never seen coolant shoot out of a header bottle unless the head (gasket) is blown.

The pressure has to come from somewhere, just pumping the water around the system will not pressurise it, the pressurisation of the system is solely due to the heat expanding the water (or should be)

A correctly filled system (not brim full) will stay in the pressure limit of the header bottle cap. unless the coolant boils when the excess pressure is bled off through the cap.

At Sea level water boils at 100 degrees C however as the pressure gets lower so will the boiling point. High up the slopes of Everest water boils at 60 degrees C and making a cup of tea is very difficult, a lot of climbers have complained about this.

In a similar way if you increase the pressure then water boils at a higher temperature, and example of this is when you reheat a cup of tea or coffee in a microwave.

If you over heat the cup when you open the door it looks fine until you move the cup and it boils up over your hand! The water in the bottom of the cup is above boiling point but cannot boil because of the pressure of the cooler water above it moving the cup disturbs the liquid and allows the hot water to move and rise to the surface where it boils.. all over your hand!

Nuclear reactors also are cooled by water.. which is at normally at over 400 Degrees C and stopped from boiling by the pressure used. (a lot)

Sorry if this sounds like a science lesson

I'm not talking about pressure, I'm talking about the surge created by the pump suddenly spinning as the engine turns. As the pump suddenly comes to life it immediately pushes against water in a large pipe (2" dia?), this movement is amplified along the much smaller diameter pipe (1/2"?) leading to the header tank.

& I do know about the effects of altitude on boiling water (one of the ways they measured the height of a mountain was measuring the boiling point of pure water)

.........just get a block test done, takes 2 minutes!

'sniff' test?

Well i have fitted a new rad. Took a while but its done.

No more leaking pipes :slayer:


But still need to test the fan, anyway i can check it? which fuse is it? can i bridge the connection?


Also how do you "a block test"

wad2502 said:

In a similar way if you increase the pressure then water boils at a higher temperature, and example of this is when you reheat a cup of tea or coffee in a microwave.

If you over heat the cup when you open the door it looks fine until you move the cup and it boils up over your hand! The water in the bottom of the cup is above boiling point but cannot boil because of the pressure of the cooler water above it moving the cup disturbs the liquid and allows the hot water to move and rise to the surface where it boils.. all over your hand!

Click to expand...

That is not quite correct as a microwave produces Radio Frequency energy at 2.4ghz, this causes the molecules in the liquid to move at that speed, they continue for some time after the microwave energy is removed this causes the odd behaviour in a cup of tea.
The best example is a pressure cooker as once it starts to boil the pressure rises and the temperature increases as the pressure rises, some pressure cookers raise the internal pressure to 2 bar and the boiling point rises way above the 100c boiling point of water at sea level.

There should be no sudden rush of water out of a header tank with no cap on when staring an engine, if so the head gasket has blown and the head will need a skim.
It was a common problem on Hillman Imps back in the 60's & 70's and the test was on a cold engine to start it give it a rev switch off and remove the radiator cap, if there was pressure in the system or water gushed out it was time to whip off the head.

It's not possible to test the fan by bridging the fuse, the fuse does not control the fan. Best bet is idle it whilst watching the temp guage, until the fan turns on, dont let the temp guage go much above 90. Turn off if in doubt.

johnhififan said:

It's not possible to test the fan by bridging the fuse, the fuse does not control the fan. Best bet is idle it whilst watching the temp guage, until the fan turns on, dont let the temp guage go much above 90. Turn off if in doubt.

Click to expand...

How do i now when it gets to 90? At moment temp sits right in the middle of guage, maybe a tad above middle.

most fans come on at 96oC & off again at around 86-88oC

If you disconnect the temp sender the fan should come on by default, never bridge out the sender though as it's ECU controlled and internal damage can occur.