Radiator information

Hi all ( New to this great little site) I was wondering if anyone knows the reason to this problem. I have bought a (s reg) 1998 hijet efi, and have come across what seems to be a common fault with these vans ( Overheating).
I noticed the guy had replaced the 2 rad caps. He replaced the thermostat which I could of sworn was stuck. So removed and tested, and was working fine. I went through the bleeding process when putting the water through but decided to flush the radiator through with a garden hose.
I removed both of the lower pipes on the rad and noticed that when I blocked the inlet pipe underneath the rad, the outlet pipe was not letting out much water(in fact pressure was building up )

My question is:

Should the water run full force through the radiator or are the veins small allowing this slight resistance. I also read on a site that the wiggle pin on a thermostat should remain at its highest point or it wont bleed. I dont understand what this means. Does it mean the pin should remain standing up when you put the themostat in as I cant see a way of doing this ( is the thermostat installed offset in the housing or do you just drop it in place hoping someone can help as my gauge is rising and dropping as, what seems to be a common fault)

Thanks all Nick

1st question, is the fan coming on?
2nd, is the heater blowing hot?
3 is it overheating or just getting pretty hot?

Logi wrote:1st question, is the fan coming on?
2nd, is the heater blowing hot?
3 is it overheating or just getting pretty hot?

Hi Thanks for your kind and quick reply

1 No the fan is not coming on was going to look at that today. Does it run off a fuse?
2 Yes heater is blowing
3 Yes it is overheating but not gurguling at the expansion tank. The temperature is well into the (H) and then drops and rises again. Surely this is no good for the engine.

1 more question (and I do appreciate your help) when yo bleed these vans it states that you run a hose through the front rad cap until the water rubs through the heater bleeder and the inside engine cap. You then close these off and run the engine. It does not state that when you run the engine (Does the expansion bottle have to be full or empty) Thanks again mate Nick

Ps when the van is ticking over it seems fine It rises when you drive?

Wiggle pin at top - thus the air can be bled out, if the thermostat sits in air it will not open =




Water should fly through the radiator from the hose pipe, if not I would suggest testing half at a time via the filler cap under the grill. The radiator flow works like this:-




Do you own a 993cc or a 1300cc?

Maybe have a scan across this:- http://www.daihatsuhijet.co.uk/hijet-overheating-problems-head-gasket-or-not/

A ticking over van has very little heat to displace as it is only burning a small amount of fuel.

When driving, you have the throttle open, with load, thus there is far more heat getting passed over to the coolant system.

Also, when the engine is under load with the throttle open, the combustion pressures in the cylinders ends up much higher as there is more air and fuel in there. This will cause any head gasket leakage to occur while at tickover with low combustion pressures it is less likely.

If the head gasket leaks, the coolant system ends up with combustion gasses in there, which displaces the water into the header tank, which then causes the van to overheat as the radiator tends to get air locked and the thermostat closes due to no coolant flow.

I am hoping it is not the head gasket as thats all I need. I was told that when a head gasket fails there should be white gunk around the oil filler but I cant see any. I am sorry to sound stupid but I still dont understand the wiggle pin situation. Does the wiggle pin have to be situated at this position as opposed to the engine. (Meaning face the wiggle pin at the top end of the engine) or does it mean not to put the thermostat upside down?
Regards the fan. Does the fan run while you are driving as I know the fan is definitely not working. The fuse box screw cover is seized which shows that someone hasnt been at it for a while. I do know that the cigarette lighter doesnt work. If they are on the same fuse then that may solve the fan.

Hijet engines do not mayo up unless there is a massive failier the thermostat in a 1.3l van has the stat on it's side so the bleed hole/wiggle pin needs to be at the top however the 993cc van has a upright stat so it does not matter as long as the stat is the correct way up which I think it won't fit the wrong way.

on my 1ltr van the head warped & there was no milky oil/water.. i had exhaust in the coolant instead.. which can be tested for with a kit from a decent car shop.

Highly unlikely to find mayo, but mine's was loaded with it. Though mine's was due to short journeys, 8000 miles in 11 years, 1/2 a mile a day each way.

As previous owner has changed stuff i'm reckoning HG, prob why they sold it....

How exactly are you bleeding it? Have you removed the bleed cover on the drivers side? Are there any leaks? Rad may be full of goo, usually why head gaskets f*ck up on them.

sounds like your rad is blocked and probably hg gone :-(
this may be helpfull
https://hijet.forumotion.com/t1041-reasons-why-my-hijet-was-over-heating-1-2-3-4-and-more

Thanks all for advice so far (Logi) I am bleeding according to the instructions on the label stuck under the front cover.
It states the following:

Drain all water from rad by undoing drain cap underneath and remove pipe as well

1 Remove inner cap from engine (Same looking one as the front Rad cap) and remove the bleeder cap held on with one of then funny clips.

2 Fill rad from front until water pours from both (Obviously replace lower pipe and drain cap)

3 replace rad cap (Front) ( Inner) and replace cover of bleeder pipe)

4 Run engine until fan kicks in 2 times ( My fan not working at the moment)

5 Top up from expansion bottle when it is low.

I noticed the link sent by (Daisydon) (Thank You) that there is a cap removed showing white foamy water.

I have seen the same in mine but is now gone

Havent had the time even to get the fuse box open at the minute as am in the middle of a dissertation for a degree but any more advice is helpful

Thank You All I really appreciate your comments so far ( Great site) Nick

I dont get this expansion system does the water suck up and then drop down because thats what it says on the sticker. Cooling system in these vans seem to be a bit over engineered if you ask me?

Need to know Is it a 1.3 or 1 litre? They are slightly different coolant systems thus why the wiggle pin stuff might not make sense to you. There is no top on a 993cc. And bleeding is different for the two systems so it's quite important.

Coolant system is very simple on a hijet, and has two "high point caps" because the foot wells stop the implementation of the standard top hose design found on most cars.

The rad cap under the drivers seat has a 1 way return valve built into the middle of it to allow coolant to be drawn back in under cooling/contraction.

fireblade101 wrote:1 Remove inner cap from engine (Same looking one as the front Rad cap) and remove the bleeder cap held on with one of then funny clips.

2 Fill rad from front until water pours from both (Obviously replace lower pipe and drain cap)

3 replace rad cap (Front) ( Inner) and replace cover of bleeder pipe)

4 Run engine until fan kicks in 2 times ( My fan not working at the moment)

5 Top up from expansion bottle when it is low.

Does your bottom hoses that goes to the radiator actually get warm? If not then the fan will never kick in as the fan sensor is in the bottom metal pipe.

I only fill from the cap under the seat, when water is spewing out of the front rad cap I put the cap on.

Then I keep filling with the bleed nipple missing. Make sure heaters are on hot mode.

Thanks (HighlyJetted) I havent checked the bottom hose as yet But if it is the one that runs from the thermostat housing, Then yes it does. As for the van. It is the 1.3 litre version.

I have the owners manual which states in big bold letters that at no point should you fill the cooling system from the inside cap under the seat.
I have done as you said and left the heater on in hot mode.

If I was to fill the rad from the front and then close off all the caps once the water flows through do i leave the front radiator cap off while the engine is running to bleed the system.
Also I didnt want to say it but is there a kit you can recommend to see if my head is gone.
Also any diagrams as to how you can replace it.
I am on a final year of a degree in Motorsport Manufacturing so have some knowledge but some tips would help Thank You Once again Nick

Oh you will learn a lot with a Hijet.......

We all.have different ways of bleeding them. Mines;
Open both caps and bleed valve.
Fill from rad till it pisses out underseat cap, put it on, continue filling slowly till it comew out top cap, put it on. Put on bleed bung. Open underseat cap. Open top cap coolant will piss out underseat one, replace top cap. I find it wastes some coolant but the gush gets any big airlocks out. Remove top cap, fill up again.
Replace top cap. Remove underseat cap and bung.
Start engine. Keep topping up underseat till it pours out the bleeder. ( a wee rev now and again).
Replace caps.
Find HG is away after all
Cry.
Come back here and we will.tell you how to fix it......

lol @ Logan!!! you speak the truth - and just beat me to a reply!

Often when your dealing with a problem van the hose can be hot at the top, but not at the bottom due to no coolant flow. Pipes get hot at the top due to convection.

If you leave either of the caps off while you run it you will end up with more air locks again, because the highest point in the system is the heater matrix. This is why block test kits don't work on a hijet, you can't test the air pocket because you don't get one under the cap(s), it goes to the heater matrix first, then to the top of the radiator, then coolant stops flowing round the system once the rad has an air pocket at the top. If you ever take the front rad cap off it lets all the water drain straight out of the heater matrix and your back to square one.

Sod the manual, Daihatsu are bloody useless! I fill from the cap under the seat, and I have made a rubber hose that fits inside the filler cap under the seat, which then goes to a length of hose pipe to a watering can, which I rest on top of the sliding door on its side. I make sure the watering can never runs out of premixed coolant as it will introduce air locks. I would highly recommend you make yourself some sort of header tank like this.

Because the watering can gives me some head height, it means that I can just start filling the whole system with a little pressure:-

when I get coolant spewing out of the front cap I put it on,
then I wait till I get coolant spewing out of the bleed nipple and put it on,
top up the watering can as you've just used a about 3 to 4 litres,
then I pull the little pipe off the neck of the radiator which ensures the heater matrix is full of coolant - when I get solid coolant I put the hose back on,
then I pull the little pipe off the thermostat - and at the same time clamp the big rad hose to the heater matrix with a brake hose clamp - this tries to ensure the block is full of coolant.
Then I pull off the little hose at the rear of the cylinder head that goes to the idle control valve - I wait for fluid to come from the idle control valve and then from the hex/arm/pipe fitting.

Also if it is an LPG one, you need to bleed the vaporizer separate from the heater matrix, but as you have a bleed nipple I would guess it is not an LPG van.

Once you have got all the air out you can (it helps if the front of the van is right up in the air on axle stands or whatever), fill the header tank to the max line, put the cap back on, then start it up. Wait for the fan to kick in a couple of times, then turn it off and leave it for a couple of hours to cool down.

I then take the cap off under the seat, top any air gap up with fluid, make sure the header tank is to the max line exactly. Then I just drive it normally for a few days, but I check the header tank every time the engine is could to see how much coolant is in there.

If it starts going higher than the max line when cold, you have got bigger problems, and if it goes much below the line, take the cap off and see if you've got a big air lock - again, you probably have bigger problems.

This is strange I drove the van today about 3 miles or so The temperature was not running into the hot but between half and 3/4 up the guage.

A mate of mine (Who owns one of these) says that the sensor that kicks the fan on is missing from where it should be. He also said that sometimes the fins on the water pump can rot.
When we opened the inner cap today in the sunshine we noticed that the water contained what looked like copper glitter floating inside (Any ideas on this one anyone)?
He told me to change the pump fix the fan and flush the system with rad cleaner.
Does this sound like good advice?

fireblade101 wrote:copper glitter floating inside
He told me to change the pump fix the fan and flush the system with rad cleaner.
Does this sound like good advice?

Copper glitter = radweld/stopleak sort of product = bad bodgy crap

This stuff is designed to block up water leakage in radiators and head gaskets etc, but it's only a temporary bodge it up sort of fix. People use it when they have a vehicle that keeps losing water - no money or will to fix it, want to get rid, etc

Unfortunately what it also does is:-

Block up radiator cap return valves in the middle
Clogs up radiators
Coats the sensors
Makes thermostat stick
Fills the bottom of the water jacket in the block with crud
blocks up all the little pipes that bleed the air to the top
Blocks up the idle control valve


I think you have to ask yourself do you want to definitely fix it, is it worth fixing? Scrap value is about £150 on the scales, maybe you'd get more on ebay if its a good example!

Or do you have time to waste, and feel like messing around doing half a job and might be a bit of fun when it doesn't work.

Proper job:-

Take head off, get it skimmed and chemically cleaned
Replace thermostat, radiator caps, hose clips
Test radiator for leaks and flow
Clean out the block while the head is off
Rebuild with new head gasket, clean coolant and oil
Fix fan kick in system

Parts and machining cost = £150 (if you don't need a radiator)
Time = a couple of days.


Messing around method:-

Drain it down, replace some bits, refill with new coolant.
Go round in circles for a few days.
Drain it down, replace some other bits, refill with coolant.
Keep going round in circles
Realise if you'd just done it properly you would have saved money on coolant and ruining more new bits, and days and days of wasted time without a working vehicle
Then do it properly wishing you'd not wasted your time.

Your mates advice is pretty sound I have to say, without a working fan it is currently doomed, and water pumps can just be visually inspected for damage.

And ask yourself without a working fan, how hot has it been before? How many times has it been boiled up? What's the chances the head isn't warped and the gasket knackard? (drove once or twice on the red bit on the gauge and they are knackard)

How long have you owned it? Did it work fine for years while you've owned it? Have you recently bought a bag of problems?

I went the half job and hope route myself the first time, and so did Daisy, and others have done it too - some then sell on the problem van unfixed when it hacks them off too bad, and then the new owner turns up here when their new ebay van boiled up on the way home


p.s. 1 lite fan switch and 1.3 is in different places. 1.3 one is in the metal coolant pipe under the passenger side footwell, screwed into a pipe boss at 90 degrees.

HighlyJetted wrote:........ There is no top on a 993cc...... .

Err, what does this mean? I take it to mean there is no top pipe across a 993cc engine -- there is.

They are slightly different coolant systems thus why the wiggle pin stuff might not make sense to you. There is no top on a 993cc.

It was in reference to the wiggle pin on the thermostat.

Ok thanks. Makes sense now. Although I thought the workshop manual did say that the thermostat had to go in the right way up -- will check when I get home, if I remember.

I'm not 100% as i've never had a 993cc.... I just thought it might be why he didn't understand the wiggle pin pointing up bit - e.g. he had a 993cc and the info/photos was regarding a 1.3. But no, he has a 1.3

IIRC the stat on the 993 sits horizontally so it wouldn't matter where the pin is (unless, obviously, the stat is upside down!)

(Highly Jetted) These are the words that you really dont want to read but you have got it in one.
Although I have always agreed that half the fun of driving or owning a car or van is being underneath it (Well it is for me)
I have no doubt in anything that you said there. and yes there are sites for most if not all vehicles that find themselves in the same situation after ebay or gum tree purchases. ( Keeps the site alive I suppose)

The head replacement according to a manual that I downloaded does not look that bad, just time consuming and sourcing a skimmer to skim the head.
I have only driven this van a couple of times and the room inside them , compared to their size is unbelievable. I have the bought the 7 seater version ( just happened to have seats) which, (even with the all the seats installed) has room to move in.
I am at present working on a 1965 VW splitscreen camper and beleive or not I would rather camp in this little highjet then the camper due to the space.
For that reason I am going to save the van from the crusher and do the work on it.
One thing I have noticed. My mate was saying that he has a sensor installed into a pipe which is the heat sensor to kick in the fan.
Mine has an empty hole with no sensor.
It does appear that someone has wired something from the rad. I am presuming that this may be an independent switch but cant find one.

Can you give me an idea how this system works. If I was to install a new sensor and run a power a new power supply to it and further run this to the fan. Would this work.

Thanks again for your honest advice mate Nick

Ps There seems to be another cap on the header unit which looks like the heater pipe bleeder but on a smaller scale.
Can you tell me what this is for Thanks again Nick

Take pics, easier to understand what & where etc.

Daisydon wll be along soon for moral support, she had a toasty one and fixed it.
HJ is fast becoming the resident Hot Hijet expert, and im full of shit so we will keep you right

haha, yeah mine was well toastie!!

im wondering how you have any water in your system tho if there is no heat sensor, just a hole??!! if i removed my sensor all the water would drain out!

and your right about the job not being particularly difficult, as long as youve got the time, space and tools and somewhere to get the head skimmed. much more cost effective than sending it to a garage to be fixed, and youll know its been done properly

Managed to get it running from A to B until I can look properly. Heres what the problem was.

There is a separate temperature sender that runs from the outlet pipe of the thermostat to the sensor connected into the rad.
This is the piece that is missing ( someone had bypassed this sensor and wired the temperature gauge direct) In other wards it is not the sensor on the rad that kicks the fan on , but a sensor that is supposed to be housed in a pipe running from the thermostat housing pipe. ( Why they did this I dont know) No explanation of this in the manual either but beleive me it is there and costs around £30.00 to replace (hence they didn't bother) I tested the fan (working) and am waiting for sensor to arrive via ebay. The fan is now running of the rear heater switch (as it was the closest and only one that does not turn lights on ow wipers etc) obviously I uprated the fuse and only use in traffic. Hope this may help someone if they are in the same boat.